AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 25, 1997

REGISTRATION NO. 333-

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM S-3
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

MERCK & CO., INC.
(EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

          NEW JERSEY                                           22-1109110
(STATE OR OTHER JURISDICTION OF                               (IRS EMPLOYER
INCORPORATION OR ORGANIZATION)                           IDENTIFICATION NUMBER)

P.O. BOX 100
ONE MERCK DRIVE
WHITEHOUSE STATION, NEW JERSEY 08889
(908) 423-1000

(ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING
AREA CODE, OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

CELIA A. COLBERT
VICE PRESIDENT AND SECRETARY
MERCK & CO., INC.
P.O. BOX 100
ONE MERCK DRIVE
WHITEHOUSE STATION, NEW JERSEY 08889
(908) 423-1000
(NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
INCLUDING AREA CODE, OF AGENT FOR SERVICE)

COPIES TO:

      KENNETH C. FRAZIER, ESQ.                                ANN B. FISHER, ESQ.
          MERCK & CO., INC.                                   SULLIVAN & CROMWELL
            P.O. BOX 100                                       125 BROAD STREET
           ONE MERCK DRIVE                                 NEW YORK, NEW YORK 10004
WHITEHOUSE STATION, NEW JERSEY 08889

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO PUBLIC: From time to time after the effective date of this Registration Statement, as determined in light of market conditions.

If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box [ ]

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. [X]

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ]

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [ ] _______________

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box. [ ]

CALCULATION OF REGISTRATION FEE

================================================================================================================
                                                                               PROPOSED MAXIMUM
                                                              PROPOSED MAXIMUM    AGGREGATE        AMOUNT OF
     TITLE OF EACH CLASS OF SECURITIES         AMOUNT TO BE    OFFERING PRICE      OFFERING       REGISTRATION
              TO BE REGISTERED                REGISTERED(1)    PER UNIT(2)(3)    PRICE(2)(3)         FEE(4)
----------------------------------------------------------------------------------------------------------------
Debt Securities.............................  $1,500,000,000        100%        $1,500,000,000      $454,545
================================================================================================================

(1) If any Debt Securities are issued (i) at an original issue discount, such greater principal amount as shall result in an aggregate offering price equal to $1,500,000,000 or (ii) with a principal amount denominated in a foreign or composite currency, such principal amount as shall result in an aggregate offering price equivalent to $1,500,000,000 at the time of the offering.

(2) Estimated solely for the purposes of computing the registration fee.

(3) Excluding accrued interest and accrued amortization of discount, if any, to the date of delivery.

(4) Pursuant to Rule 429, $170,000,000 of debt securities are being carried forward from Registration Statement No. 33-60322 for sale under the Prospectus filed herewith. A registration fee of $53,125 was paid with respect to such debt securities.

THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE SECURITIES ACT OF 1993 OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a), MAY DETERMINE.

PURSUANT TO RULE 429, THE PROSPECTUS CONTAINED IN THIS REGISTRATION STATEMENT ALSO RELATES TO $170,000,000 OF UNISSUED DEBT SECURITIES REGISTERED UNDER FORM S-3 REGISTRATION STATEMENT NO. 33-60322.


INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR

MAY OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT BECOMES EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS OF SUCH STATE.

                SUBJECT TO COMPLETION, DATED SEPTEMBER   , 1997

PROSPECTUS

                                 $1,670,000,000

          [LOGO]               MERCK & CO., INC.
                                DEBT SECURITIES
                            ------------------------

Merck & Co., Inc. (the "Company") may offer from time to time in one or more series its debt securities (the "Debt Securities") at an aggregate initial offering price not to exceed $1,670,000,000 (or its equivalent in foreign currencies or currency units). The Company will offer Debt Securities to the public on terms determined by market conditions.


The accompanying Prospectus Supplement sets forth the specific designation, aggregate principal amount, purchase price, maturity, interest rate (or manner of calculation thereof), time of payment of interest (if any), listing (if any) on a securities exchange, the form of the Debt Securities (which may be in registered form or book-entry form) and any other specific terms of the Debt Securities and the name of and compensation to each dealer, underwriter, or agent (if any) involved in the sale of the Debt Securities covered by the Prospectus Supplement.


THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE

CONTRARY IS A CRIMINAL OFFENSE.


Debt Securities may be offered through dealers, through underwriters, or through agents designated from time to time, as set forth in the Prospectus Supplement, and Debt Securities may be offered to other purchasers directly or through agents. Net proceeds to the Company will be the purchase price in the case of a purchaser or dealer, the public offering price less discount in the case of an underwriter, or the purchase price less commission in the case of an agent -- in each case, less other expenses attributable to issuance and distribution. See "Plan of Distribution" for possible indemnification arrangements for dealers, underwriters, and agents.


This Prospectus may not be used to consummate the sale of any Securities unless accompanied by a Prospectus Supplement.


THE DATE OF THIS PROSPECTUS IS , 1997


NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATION OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS AND ANY ACCOMPANYING PROSPECTUS SUPPLEMENT IN CONNECTION WITH THE OFFERING DESCRIBED HEREIN AND THEREIN, AND, IF GIVEN OR MADE, SUCH OTHER INFORMATION OR REPRESENTATION MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED BY THE COMPANY OR BY ANY UNDERWRITER, DEALER OR AGENT. NEITHER THIS PROSPECTUS NOR ANY PROSPECTUS SUPPLEMENT SHALL CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN OFFER TO BUY ANY SECURITIES OFFERED HEREUNDER IN ANY JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR SOLICITATION OR SALE IN SUCH JURISDICTION. NEITHER THE DELIVERY OF THIS PROSPECTUS OR ANY PROSPECTUS SUPPLEMENT NOR ANY SALE MADE HEREUNDER IMPLIES THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY AT ANY TIME SUBSEQUENT TO THE DATE HEREOF OR THAT THE INFORMATION HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO ITS DATE.

AVAILABLE INFORMATION

The Company is subject to the informational requirements of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and in accordance therewith files reports, proxy statements and other information with the Securities and Exchange Commission (the "Commission").

All such reports, proxy statements and other information, including the documents incorporated by reference herein, can be inspected and copied at prescribed rates at the public reference facilities maintained by the Commission at 450 Fifth Street, N.W., Washington, D.C. 20549, and at the Commission's regional offices at 7 World Trade Center, 13th floor, New York, New York 10048, and 1400 Citicorp Center, 500 West Madison Street, Suite 1400, Chicago, Illinois 60661. Certain of such reports, proxy statements and other information are also available over the Internet at http://www.sec.gov. Such material can also be inspected at the office of the New York Stock Exchange, 20 Broad Street, New York, New York 10005, and at the office of the Philadelphia Stock Exchange, 1900 Market Street, Philadelphia, Pennsylvania 19130.

The Company has filed a registration statement on Form S-3 (herein, together with all amendments and exhibits, referred to as the "Registration Statement") under the Securities Act of 1933, as amended (the "Securities Act"), with respect to the securities offered hereby. This Prospectus does not contain all of the information set forth in the Registration Statement, certain parts of which are omitted in accordance with the rules and regulations of the Commission. For further information, reference is made to the Registration Statement and the exhibits filed as a part thereof. Statements contained herein concerning any document filed as an exhibit are not necessarily complete and, in each instance, reference is made to the copy of such document filed as an exhibit to the Registration Statement. Each such statement is qualified in its entirety by such reference.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The following documents filed by the Company (Exchange Act File No. 1-3305) with the Commission are hereby incorporated by reference into this Prospectus:

(a) Annual Report on Form 10-K, filed March 19, 1997, for the fiscal year ended December 31, 1996.

(b) Quarterly Report on Form 10-Q, filed on May 13, 1997, for the quarter ended March 31, 1997.

(c) Current Report on Form 8-K, filed May 15, 1997.

(d) Quarterly Report on Form 10-Q, filed August 13, 1997, for the quarter ended June 30, 1997.

All documents filed by the Company pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this Prospectus and prior to the termination of the offering of the Debt Securities hereby shall be deemed to be incorporated by reference into this Prospectus and to be a part of this Prospectus from the date of filing of such document.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Prospectus and the Registration Statement

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of which it is a part to the extent that a statement contained herein or in any other subsequently filed document which is also incorporated or deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Prospectus or such Registration Statement.

The Company will provide without charge to each person to whom a copy of this Prospectus has been delivered, upon written or oral request of such person, a copy of any or all of the documents which have been or may be incorporated herein by reference, other than exhibits to such documents (unless such exhibits are specifically incorporated by reference into the information that the Registration Statement incorporates). Requests for such copies should be directed to the Office of the Secretary, Merck & Co., Inc., P.O. Box 100, One Merck Drive, Whitehouse Station, New Jersey 08889-0100, telephone number (800) 613-2104.

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THE COMPANY

The Company is a leading research-driven pharmaceutical company that discovers, develops, manufactures and markets a broad range of human and animal health products and services.

Human health products include therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. Among these are elevated cholesterol products, hypertension/heart failure products, anti-ulcerants, antibiotics, opthalmologicals, vaccines/biologicals, benign prostatic hyperplasia products, osteoporosis products, an HIV protease inhibitor, anti-inflammatories/analgesics, psychotherapeutics and a muscle relaxant. The Company also provides human health services, principally managed prescription drug programs.

A portion of the Company's human health products business is conducted through joint ventures, including joint ventures with Astra AB, Johnson & Johnson, E.I. DuPont de Nemours and Company, Pasteur-Merieux Connaught and American Home Products Corporation.

Through a joint venture with Rhone-Poulenc, the Company also conducts an animal health and poultry genetics business. The joint venture, which is equally owned by the Company and Rhone-Poulenc, conducts the Company's and Rhone Poulenc's former animal health and poultry genetics businesses. Animal health products include medicinals used to control and alleviate disease in livestock, small animals and poultry. These products are primarily antiparasitics and also include coccidiostats for the treatment of poultry diseases. The poultry genetics business products include poultry breeding stock selected for increased or improved meat or egg production.

The Company was incorporated in the State of New Jersey in 1927 and maintains its principal offices at Whitehouse Station, New Jersey. The Company's address is P.O. Box 100, One Merck Drive, Whitehouse Station, New Jersey 08889-0100 and its telephone number is (908) 423-1000.

USE OF PROCEEDS

Except as otherwise described in the applicable Prospectus Supplement, the Company intends to use the net proceeds from the sale of the Debt Securities for general corporate purposes, including the reduction of short-term debt. Funds not required immediately for such purposes may be invested temporarily in short-term marketable securities.

RATIOS OF EARNINGS TO FIXED CHARGES

The following table sets forth the Company's consolidated ratios of earnings to fixed charges for the indicated periods:

                                            SIX
                                           MONTHS
                                           ENDED               YEAR ENDED DECEMBER 31,
                                          JUNE 30,     ----------------------------------------
                                            1997       1996     1995     1994     1993     1992
                                          --------     ----     ----     ----     ----     ----
Ratio of earnings to fixed charges......     29         23       38       28       27       34

For purposes of computing these ratios, "earnings" consist of income before income taxes, cumulative effect of accounting changes, one-third of rents (deemed by the Company to be representative of the interest factor inherent in rents), interest expense, net of amounts capitalized, and dividends on preferred stock of subsidiary companies. "Fixed charges" consist of one-third of rents, interest expense as reported in the Company's consolidated financial statements and dividends on preferred stock of subsidiary companies.

DESCRIPTION OF DEBT SECURITIES

The Debt Securities are to be issued under the Indenture dated as of April 1, 1991, as amended and supplemented (the "Indenture"), between the Company and First Trust of New York, National Association,

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as Trustee (the "Trustee"), a copy of which is filed (or incorporated by reference) as an exhibit to the Registration Statement. The following summaries of certain provisions of the Indenture do not purport to be complete and are subject to, and are qualified in their entirety by reference to, all the provisions of the Indenture, including the definitions therein of certain terms. Wherever particular Sections or defined terms of the Indenture are referred to, such Sections or defined terms are incorporated herein by reference.

The following sets forth certain general terms and provisions of the Debt Securities offered hereby. The particular terms of the Debt Securities offered by any Prospectus Supplement (the "Offered Debt Securities") will be described in the Prospectus Supplement relating to such Offered Debt Securities (the "Applicable Prospectus Supplement").

GENERAL

The Indenture does not limit the amount of Debt Securities that may be issued thereunder and Debt Securities may be issued thereunder from time to time in one or more series. The Debt Securities will be unsecured and unsubordinated obligations of the Company and will rank equally and ratably with other unsecured and unsubordinated obligations of the Company.

Unless otherwise indicated in the Applicable Prospectus Supplement, principal of, premium, if any, and interest on the Debt Securities will be payable, and the transfer of Debt Securities will be registrable, at the office or agency to be maintained by the Company in The City of New York and at any other office or agency maintained by the Company for such purpose. (Sections 301, 305 and 1002) The Debt Securities will be issued only in fully registered form without coupons and, unless otherwise indicated in the Applicable Prospectus Supplement, in denominations of $1,000 or integral multiples thereof. (Section 302) No service charge will be made for any registration of transfer or exchange of the Debt Securities, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge imposed in connection therewith. (Section 305)

The Applicable Prospectus Supplement will describe the following terms of the Offered Debt Securities: (1) the title of the Offered Debt Securities; (2) any limit on the aggregate principal amount of the Offered Debt Securities; (3) the Person to whom any interest on the Offered Debt Securities shall be payable, if other than the Person in whose name that Security (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest; (4) the date or dates on which the principal of the Offered Debt Securities is payable; (5) the rate or rates at which the Offered Debt Securities shall bear interest, if any, the date or dates from which any such interest shall accrue, the Interest Payment Dates on which any such interest shall be payable and the Regular Record Date for the interest payable on any Interest Payment Date; (6) the place or places where the principal of and any premium and interest on the Offered Debt Securities shall be payable; (7) the period or periods within which, the price or prices at which and the terms and conditions upon which the Offered Debt Securities may be redeemed, in whole or in part, at the option of the Company; (8) the obligation, if any, of the Company to redeem or purchase the Offered Debt Securities pursuant to any sinking fund or analogous provisions or at the option of a Holder thereof and the period or periods within which, the price or prices at which and the terms and conditions upon which the Offered Debt Securities shall be redeemed or purchased, in whole or in part, pursuant to such obligation; (9) if other than denominations of $1,000 and any integral multiple thereof, the denominations in which the Offered Debt Securities shall be issuable; (10) the currency, currencies or currency units in which payment of the principal of and any premium and interest on any Offered Debt Securities shall be payable if other than the currency of the United States of America; (11) if the amount of payments of principal of or any premium or interest on any Offered Debt Securities may be determined with reference to an index or formula, the manner in which such amounts shall be determined; (12) if the principal of or any premium or interest on any Offered Debt Securities is to be payable, at the election of the Company or a Holder thereof, in one or more currencies or currency units other than that or those in which the Securities are stated to be payable, the currency, currencies or currency units in which payment of the principal of and any premium and interest on the Offered Debt Securities as to which such election is made shall be payable, and the periods within which and the terms and conditions upon which such election is to be made; (13) if other than the principal amount thereof, the portion of the principal amount of the Offered Debt Securities which shall be payable upon

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declaration of acceleration of the Maturity thereof; (14) the applicability of the provisions described under "Defeasance and Covenant Defeasance"; (15) if the Offered Debt Securities will be issuable only in the form of a Book-Entry Security as described under "Book-Entry Debt Securities," the Depository or its nominee with respect to the Offered Debt Securities and the circumstances under which the Book-Entry Security may be registered for transfer or exchange or authenticated and delivered in the name of a Person other than the Depository or its nominee; and (16) any other terms of the Offered Debt Securities. (Section 301)

The Debt Securities may be issued as Original Issue Discount Debt Securities to be offered and sold at a substantial discount below their stated principal amount. Federal income tax consequences and other special considerations applicable to Original Issue Discount Debt Securities and any Debt Securities treated as having been issued with original issue discount for Federal income tax purposes will be described in the Applicable Prospectus Supplement. "Original Issue Discount Debt Securities" means any Debt Security which provides for an amount less than the principal amount thereof to be due and payable upon the declaration of acceleration of the Maturity thereof upon the occurrence of an Event of Default and the continuation thereof. (Section 101)

BOOK-ENTRY DEBT SECURITIES

The Debt Securities of a series may be issued in the form of one or more Book-Entry Securities that will be deposited with a Depository or its nominee identified in the Applicable Prospectus Supplement. In such a case, one or more Book-Entry Securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal amount of Outstanding Debt Securities of the series to be represented by such Book-Entry Security or Securities. Unless and until it is exchanged in whole or in part for Debt Securities in definitive registered form, a Book-Entry Security may not be registered for transfer or exchange except as a whole by the Depository for such Book-Entry Security to a nominee or such Depository and except in the circumstances described in the Applicable Prospectus Supplement. (Sections 204 and 305)

The specific terms of the depository arrangement with respect to any portion of a series of Debt Securities to be represented by a Book-Entry Security will be described in the Applicable Prospectus Supplement.

CERTAIN COVENANTS OF THE COMPANY

Subsidiaries. The term "Subsidiary" is defined in the Indenture as a corporation more than 50% of the outstanding stock of which is owned directly or indirectly by the Company and/or one or more Subsidiaries. The term "Domestic Subsidiary" is defined in the Indenture as a Subsidiary substantially all the fixed assets of which are located, or substantially all the business of which is carried on, within the United States (including Puerto Rico), or which owns or leases any Principal Domestic Manufacturing Property, but such term excludes any Subsidiary the principal business of which is the financing of the operations of the Company or its Subsidiaries outside the United States (including Puerto Rico) (but such Subsidiary is excluded only so long as it neither owns nor leases any Principal Domestic Manufacturing Property). (Section 101)

Restrictions on Secured Debt. The Indenture provides that if the Company or any Domestic Subsidiary shall incur, issue, assume or guarantee any Debt secured by a Mortgage on any Principal Domestic Manufacturing Property of the Company or any Domestic Subsidiary or on any shares of stock or Debt of any Domestic Subsidiary, the Company will secure, or cause such Domestic Subsidiary to secure, the Outstanding Debt Securities equally and ratably with (or prior to) such secured Debt, unless after giving effect thereto the aggregate amount of all such secured Debt together with all Attributable Debt of the Company and of any Domestic Subsidiary in respect of sale and leaseback transactions involving Principal Domestic Manufacturing Properties would not exceed 10% of the Consolidated Net Tangible Assets of the Company and its consolidated Subsidiaries. For the purpose of providing such equal and ratable security, the principal amount of Outstanding Debt Securities of any series of Original Issue Discount Securities shall be such portion of the principal amount as specified in the terms of that series that would be payable upon acceleration of the Maturity thereof at the time of such determination. This restriction will not apply to, and there shall be excluded in computing secured Debt for the purpose of such restriction, Debt secured by (a) Mortgages on property of, or on any shares of stock or Debt of, any corporation existing at the time such corporation

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becomes a Domestic Subsidiary, (b) Mortgages in favor of the Company or a Domestic Subsidiary, (c) Mortgages in favor of governmental bodies of the United States or any State or Puerto Rico or any other country or any political subdivision thereof to secure partial, progress or advance payments, (d) Mortgages on property, shares of stock or Debt, purchase money Mortgages and construction Mortgages existing at or incurred within 120 days of the time of acquisition thereof (including acquisition through merger or consolidation), and
(e) certain extensions, renewals or replacements of Mortgages referred to in the foregoing clauses (a) through (d) inclusive. (Section 1008) The Indenture does not restrict the incurrence of unsecured Debt by the Company or its Subsidiaries.

"Principal Domestic Manufacturing Property" is defined in the Indenture to include any facility (together with the land on which it is erected and fixtures comprising a part thereof) used primarily for manufacturing, processing or warehousing of the Company's products and located in the United States (including Puerto Rico), owned or leased by the Company or a Subsidiary and having a gross book value in excess of 1% of Consolidated Net Tangible Assets, other than any such facility or portion thereof (i) which is financed by certain governmental obligations the interest on which is excludable from gross income of the holder thereof pursuant to the provisions of Section 103 (a) of the Internal Revenue Code or Section 745 of Title 48 of the United States Code or
(ii) which in the opinion of the Board of Directors of the Company is not of material importance to the total business conducted by the Company and its Subsidiaries as an entirety. "Consolidated Net Tangible Assets" is defined as the aggregate amount of all assets (after deducting intangible assets and the amount of all current liabilities) of the Company and its consolidated Subsidiaries. "Mortgage" is defined as any mortgage, pledge, lien, security interest, conditional sale or other title retention agreement or similar encumbrance. "Attributable Debt" is defined to mean the total net amount of rent (discounted at the rate of 1% per annum over the weighted average Yield to Maturity of the Outstanding Debt Securities compounded semi-annually) required to be paid during the remaining term of any lease. (Section 101)

Restrictions on Sales and Leaseback Transactions. The Indenture provides that neither the Company nor any Domestic Subsidiary may, after the effective date of the Indenture, enter into any sale and leaseback transaction involving any Principal Domestic Manufacturing Property which has been or is to be sold or transferred, more than 120 days afer the acquisition thereof or the completion of construction and commencement of full operations thereof, unless (a) the Company or such Domestic Subsidiary could create Debt secured by a Mortgage on such property as described under "Restrictions on Secured Debt" in an amount equal to the Attributable Debt with respect to the sale and leaseback transaction without equally and ratably securing the Outstanding Debt Securities or (b) the Company, within 120 days, applies to the retirement of its Funded Debt which is pari passu (as defined in the Indenture) with the Outstanding Securities an amount equal to the greater of (i) the net proceeds of the sale of the Principal Domestic Manufacturing Property leased pursuant to such arrangement or (ii) the fair market value of the Principal Domestic Manufacturing Property so leased (subject to credits for certain voluntary retirements of Funded Debt). (Section 1009) "Funded Debt" is defined as indebtedness for money borrowed having a maturity at or being renewable or extendible to a date more than 12 months from the date of determination. (Section 101) This restriction does not apply to any sale and leaseback transaction (a) between the Company and a Subsidiary or between Subsidiaries, or
(b) involving the taking back of a lease for a period of three years or less.
(Section 1009)

Unless otherwise indicated in the Applicable Prospectus Supplement, the Indenture does not contain covenants specifically designed to protect Holders in the event of a highly leveraged transaction involving the Company.

EVENTS OF DEFAULT

Any one of the following events constitutes an Event of Default under the Indenture with respect to Securities of any series: (a) failure to pay any interest on any Debt Security of that series when due, continued for 30 days;
(b) failure to pay principal of or any premium on any Debt Security of that series when due; (c) failure to deposit any sinking fund payment, when due, in respect of any Debt Security of that series; (d) failure to perform, or breach of, any covenant or warranty of the Company in the Indenture (other than a

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covenant included in the Indenture solely for the benefit of a series of Debt Securities thereunder other than that series) continued for 90 days after written notice as provided in the Indenture; (e) certain events in bankruptcy, insolvency or reorganization of the Company; or (f) any other Event of Default provided with respect to Debt Securities of that series. (Section 501)

If any Event of Default with respect to the Debt Securities of any series at the time Outstanding occurs and is continuing, either the Trustee or the Holders of at least 25 percent in aggregate principal amount of the Outstanding Debt Securities of that series may declare the principal amount (or, if the Debt Securities of that series are Original Issue Discount Debt Securities, such portion of the principal amount as may be specified in the terms thereof) of all the Debt Securities of that series to be due and payable immediately. At any time after a declaration of acceleration with respect to Debt Securities of any series has been made, but before a judgment or decree based on acceleration has been obtained, the Holders of a majority in aggregate principal amount of Outstanding Debt Securities of that series may, under certain circumstances, rescind and annul such acceleration. (Section 502)

Reference is made to the Applicable Prospectus Supplement relating to any series of Offered Debt Securities that are Original Issue Discount Debt Securities for the particular provisions relating to acceleration of the Stated Maturity of a portion of the principal amount of such series of Original Issue Discount Debt Securities upon the occurrence of an Event of Default and the continuation thereof.

The Indenture provides that, subject to the duty of the Trustee during default to act with the required standard of care, the Trustee will be under no obligation to exercise any of its rights or powers under the Indenture at the request or direction of any of the Holders, unless such Holders shall have offered to the Trustee reasonable indemnity. (Section 603) Subject to such provisions for the indemnification of the Trustee and to certain other conditions, the Holders of a majority in aggregate principal amount of the Outstanding Debt Securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee, or exercising any trust or power conferred on the Trustee, with respect to the Debt Securities of that series. (Section 512)

No Holder of any series of Debt Securities will have any right to institute any proceeding with respect to the Indenture or for any remedy thereunder, unless such Holder shall have previously given to the Trustee written notice of a continuing Event of Default and unless the Holders of at least 25 percent in principal amount of the Outstanding Debt Securities of that series shall have made written request, and offered reasonable indemnity, to the Trustee to institute such proceeding as trustee, and the Trustee shall not have received from the Holders of a majority in aggregate principal amount of the Outstanding Debt Securities of that series a direction inconsistent with such request and shall have failed to institute such proceeding within 60 days. (Section 507) However, such limitations do not apply to a suit instituted by a Holder of a Debt Security for enforcement of payment of the principal of and premium, if any, or interest on such Debt Security on or after the respective due dates expressed in such Debt Security. (Section 508)

The Company is required to furnish to the Trustee annually a statement as to the performance by the Company of certain of its obligations under the Indenture and as to any default in such performance. (Section 1004)

MODIFICATION AND WAIVER

Modifications and amendments of the Indenture may be made by the Company and the Trustee with the consent of the Holders of not less than a majority in aggregate principal amount of the Outstanding Debt Securities of each series issued under the Indenture and affected by the modification or amendments; provided, however, that no such modification or amendment may, without the consent of the Holders of all Debt Securities affected thereby, (i) change the Stated Maturity of the principal of, or any installment of principal of or interest on, any Debt Security, (ii) reduce the principal amount of, or the premium, if any, or (except as otherwise provided in the Applicable Prospectus Supplement) interest on, any Debt Security (including in the case of an Original Issue Discount Debt Security the amount payable upon acceleration of the Maturity thereof); (iii) change the place or currency of payment of principal of, premium, if any, or interest on any Debt Security; (iv) impair the right to institute suit for the enforcement of any payment on any

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Debt Security on or after the Stated Maturity thereof (or in the case of redemption, on or after the Redemption Date); or (v) reduce the percentage in principal amount of Outstanding Debt Securities of any series, the consent of whose Holders is required for modification or amendment of the Indenture or for waiver of compliance with certain provisions of the Indenture or for waiver of certain defaults. (Section 902)

The Holders of at least a majority in aggregate principal amount of the Outstanding Debt Securities of any series may, on behalf of all Holders of that series, waive compliance by the Company with certain restrictive provisions of the Indenture. (Section 1010) The Holders of not less than a majority in aggregate principal amount of the Outstanding Debt Securities of any series may, on behalf of all Holders of that series, waive any past default under the Indenture, except a default in the payment of principal, premium or interest or in respect of a covenant or provision of the Indenture that cannot be modified or amended without the consent of the Holder of each Outstanding Debt Security of such series affected thereby. (Section 513)

CONSOLIDATION, MERGER AND SALE OF ASSETS

The Company may not consolidate with or merge into any other Person or transfer or lease its assets substantially as an entirety to any Person and may not permit any Person to merge into or consolidate with the Company or transfer or lease its assets substantially as an entirety to the Company, unless (i) any successor or purchaser is a corporation, partnership, or trust organized under the laws of the United States of America, any State or the District of Columbia, and any such successor or purchaser expressly assumes the Company's obligations on the Debt Securities under a supplemental Indenture, (ii) immediately after giving effect to the transaction no Event of Default, and no event which, after notice or lapse of time or both, would become an Event of Default, shall have occurred and be continuing, (iii) if properties or assets of the Company become subject to a Mortgage not permitted by the Indenture, the Company or such successor Person, as the case may be, takes such steps as shall be necessary effectively to secure the Securities equally and ratably with (or prior to) all indebtedness secured thereby, and (iv) the Company has delivered to the Trustee an Officers' Certificate and an Opinion of Counsel stating compliance with these provisions. (Section 801)

DEFEASANCE AND COVENANT DEFEASANCE

The Indenture provides, unless otherwise indicated in the Applicable Prospectus Supplement with respect to the Offered Debt Securities, that the Company, at the Company's option, (a) will be discharged from any and all obligations in respect of the Debt Securities of any series (except for certain obligations to register the transfer of or exchange of Debt Securities of such series, replace stolen, lost or mutilated Debt Securities of such series, maintain paying agencies and hold moneys for payment in trust) or (b) need not comply with certain restrictive covenants of the Indenture, including those described under "Certain Covenants", and the occurrence of an event described in clause (e) under "Events of Default" shall no longer be an Event of Default, in each case, if the Company deposits, in trust, with the Trustee money or U.S. Government Obligations, which through the payment of interest thereon and principal thereof in accordance with their terms will provide money, in an amount sufficient to pay all the principal of and interest on the Debt Securities of such series on the dates such payments are due (which may include one or more redemption dates designated by the Company) in accordance with the terms of the Debt Securities of such series. Such a trust may only be established if, among other things, (i) no Event of Default or event which with the giving of notice or lapse of time, or both, would become an Event of Default under the Indenture shall have occurred and be continuing on the date of such deposit, (ii) such deposit will not cause the Trustee to have any conflicting interest with respect to other securities of the Company and (iii) the Company shall have delivered an Opinion of Counsel to the effect that the Holders will not recognize income, gain or loss for Federal income tax purposes as a result of such deposit or defeasance and will be subject to Federal income tax in the same manner as if such defeasance had not occurred, which Opinion of Counsel, in the case of clause (a) above, must refer to and be based upon a published ruling of the Internal Revenue Service, a private ruling of the Internal Revenue Service addressed to the Company, or otherwise a change in applicable Federal income tax law occurring after the date of the Indenture. In the event the Company omits to comply with its remaining obligations under the Indenture after a defeasance of the Indenture with respect to the Debt Securities of any series as described under clause (b) above and the Debt Securities of such series are declared due and payable

9

because of the occurrence of any Event of Default, the amount of money and U.S. Government Obligations on deposit with the Trustee may be insufficient to pay amounts due on the Debt Securities of such series at the time of the acceleration resulting from such Event of Default. However, the Company will remain liable in respect of such payments. (Article Thirteen)

CONCERNING THE TRUSTEE

First Trust of New York, National Association, is Trustee under the Indenture. The Trustee performs services for the Company in the ordinary course of business.

PLAN OF DISTRIBUTION

The Company may sell the Debt Securities being offered hereby through agents, through underwriters and through dealers, and Debt Securities may be sold to other purchasers directly or through agents.

The distribution of the Debt Securities may be effected from time to time in one or more transactions at a fixed price or prices, which may be changed, or at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices.

In connection with the sale of Debt Securities, underwriters may receive compensation from the Company or from purchasers of Debt Securities for whom they may act as agents in the form of discounts, concessions or commissions. Underwriters may sell Debt Securities to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents. Underwriters, dealers and agents that participate in the distribution of Debt Securities may be deemed to be underwriters, and any discounts or commissions received by them from the Company, and any profit on the resale of Debt Securities by them, may be deemed to be underwriting discounts and commissions, under the Securities Act. Any such underwriter or agent will be identified, and any such compensation received from the Company will be described, in the Applicable Prospectus Supplement.

Underwriters, dealers and agents that participate in the distribution of the Debt Securities or their affiliates may be customers of, extend credit to or engage in transactions with or perform services for the Company in the ordinary course of business.

The Debt Securities are not proposed to be listed on a securities exchange, and any underwriters or dealers will not be obligated to make a market in Debt Securities. The Company cannot predict the activity or liquidity of any trading in the Debt Securities.

Underwriters participating in the offering of the Debt Securities may purchase and sell Debt Securities in the open market. These transactions may include overallotment and stabilizing transactions and purchasees to cover short positions created by such underwriters in connection with the offering. Such underwriters may also impose a penalty bid, whereby selling concessions allowed to broker-dealers in respect of the Debt Securities sold in the offering may be reclaimed by such underwriters if such Debt Securities are repurchased by the underwriters in stabilizing transactions. These activities may stabilize, maintain or otherwise affect the market price of the Debt Securities, which may be higher than the price that might otherwise prevail in the open market; and these activities, if commenced, may be discontinued at any time.

VALIDITY OF DEBT SECURITIES

The validity of Debt Securities offered hereby will be passed upon for the Company by Mary M. McDonald, Esq., Senior Vice President and General Counsel of the Company, and for any underwriters or agents by Sullivan & Cromwell, New York, New York. Ms. McDonald and her husband beneficially own an aggregate of 35,622 shares of Common Stock and hold options to acquire 600 shares which are exercisable within 60 days.

10

EXPERTS

The consolidated financial statements of the Company at December 31, 1996 and 1995 and for each of the three years in the period ended December 31, 1996, appearing in its Annual Report on Form 10-K, for the fiscal year ended December 31, 1996 and incorporated in this Prospectus by reference, have been audited by Arthur Andersen LLP, independent public accountants, as indicated in their reports with respect thereto and incorporated by reference herein. The financial statements referred to above are included in reliance upon the reports of said firm and upon the authority of said firm as experts in auditing and accounting.

11

PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

The Company estimates that expenses, other than underwriting compensation, in connection with the offering described in this Registration Statement will be as follows:

Registration Fee..................................................  $454,545
Trustee's Fees....................................................    35,000
Printing and Engraving............................................    10,000
Legal Fees........................................................   100,000
Accounting Fees...................................................    20,000
Rating Agency Fees................................................   100,000
Blue Sky Fees and Expenses........................................     5,000
Miscellaneous.....................................................    10,000
          Total...................................................  $734,545
                                                                    ========

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

The New Jersey Business Corporation Act provides that a New Jersey corporation has the power to indemnify a director or officer against his or her expenses and liabilities in connection with any proceeding involving the director or officer by reason of his or her being or having been such a director or officer, other than a proceeding by or in the right of the corporation, if such a director or officer acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation; and with respect to any criminal proceeding, such director or officer had no reasonable cause to believe his or her conduct was unlawful.

The indemnification and advancement of expenses shall not exclude any other rights, including the right to be indemnified against liabilities and expenses incurred in proceedings by or in the right of the corporation, to which a director or officer may be entitled under a certificate of incorporation, bylaw, agreement, vote of shareholders, or otherwise; provided that no indemnification shall be made to or on behalf of a director or officer if a judgment or other final adjudication adverse to the director or officer establishes that his or her omissions (a) were in breach of his or her duty of loyalty to the corporation or its shareholders, (b) were not in good faith or involved a knowing violation of law or (c) resulted in receipt by the director or officer of an improper personal benefit.

The Company's Restated Certificate of Incorporation provides that, to the fullest extent permitted by the laws of the State of New Jersey, directors and officers of the Corporation shall not be personally liable to the Corporation or its stockholders for damages for breach of any duty owed to the Corporation or its stockholders, except that a director or officer shall not be relieved from liability for any breach of duty based upon an act or omission (a) in breach of such person's duty of loyalty to the Corporation or its stockholders, (b) not in good faith or involving a knowing violation of law or (c) resulting in receipt by such person of an improper personal benefit.

The By-Laws of the Company provide that a former, present or future director, officer or employee of the Company or the legal representative of any such director, officer or employee shall be indemnified by the Company:

(a) against reasonable costs, disbursements and counsel fees paid or incurred where such person has been successful in the defense on the merits or otherwise of any pending, threatened or completed civil, criminal, administrative or arbitrative action, suit or proceeding, brought by reason of such person's being or having been such director, officer or employee,

and


(b) with respect to the defense of any such action, suit, proceeding, inquiry or investigation for which indemnification is not made under (a) above, against reasonable costs, disbursements (which shall include amounts paid in satisfaction of settlements, judgments, fines and penalties, exclusive, however, of any amount paid or payable to the Company) and counsel fees if such person acted in good faith and in a manner such person reasonably believed to be in or not opposed to the best interests of the Company, and in connection with any criminal proceedings such person also had no reasonable cause to believe the conduct was unlawful, with the determination as to whether the applicable standard of conduct was met to be made by a majority of the members of the Board of Directors (sitting as a Committee of the Board) who were not parties to such inquiry, investigation, action, suit or proceeding or by any one or more disinterested counsel to whom the question may be referred by the Board of Directors; provided, however, in connection with any proceeding by or in the right of the Company, no indemnification shall be provided as to any person adjudged by any court to be liable to the Company except as and to the extent determined by such court.

The Company enters into indemnification agreements with its directors and officers and enters into insurance agreements on its own behalf. The indemnification agreements provide that the Company agrees to hold harmless and indemnify its directors and officers to the fullest extent authorized or permitted by the Business Corporation Act of the State of New Jersey, or any other applicable law, or by any amendment thereof or other statutory provisions authorizing or permitting such indemnification that is adopted after the date hereof. Without limiting the generality of the foregoing, the Company agrees to hold harmless and indemnify its directors and officers to the fullest extent permitted by applicable law against any and all expenses, judgments, fines, and amounts paid in settlement actually and reasonably incurred by its directors and officers in connection with the defense of any present or future threatened, pending, or completed claim, action, suit, or proceeding by reason of the fact that they were, are, shall be, or shall have been a director or officer of the Company, or are or were serving, shall serve, or shall have served, at the request of the Company, as a director or officer of another corporation, partnership, joint venture, trust, employee benefit plan, or other enterprise.

A Resolution adopted by the Company's Board of Directors provides, that to the extent permitted by applicable law and not prohibited by the Company's Certificate of Incorporation or By-laws, the Company shall (i) indemnify and save harmless each and every past and present director and officer of the Company against any and all losses, claims, damages or liabilities to which such officer or director may become subject, under the Securities Act, the Exchange Act, any state Blue Sky or securities law or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise in connection with this Registration Statement or any amendments (including, without limitation, post effective amendments) or supplements thereto and any Prospectus included therein and (ii) reimburse each such director and officer for any legal or other expenses reasonably incurred by him or her in connection with investigating or defending any such action or claim.

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ITEM 16. EXHIBITS.

 1         --   Form of Underwriting Agreement.
 4  (a)    --   Indenture between the Company and Morgan Guaranty Trust Company of New York, as
                Trustee (incorporated herein by reference to Exhibit (4) to the Company's
                Registration Statement on Form S-3 (No. 33-39349)).
 4  (b)    --   Form of First Supplemental Indenture between the Company and First Trust of New
                York, National Association, as Trustee.
 5         --   Opinion and Consent of Mary M. McDonald, Esq.
12         --   Computation of Ratio of Earnings to Fixed Charges (incorporated herein by
                reference to Exhibit 12 to the Company's Quarterly Report on Form 10-Q for the
                quarterly period ended June 30, 1997 (File No. 1-03305)).
23  (a)    --   Consent of Arthur Andersen LLP.
23  (b)    --   Consent of Counsel (included in Exhibit 5).
24         --   Power of Attorney (included in the signature page hereto).
25         --   Statement of Eligibility and Qualification on Form T-1 under the Trust Indenture
                Act of 1939, as amended, of First Trust of New York, National Association.

ITEM 17. UNDERTAKINGS.

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

(i) To include any prospectus required by section 10 (a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (i) and (ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to section 13(a) or section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan's annual report pursuant to section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the provisions described under Item 15

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above or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted against the registrant by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has theretofore been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, Merck & Co., Inc. certifies that it has reasonable grounds to believe that it meets all the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, at Whitehouse Station, State of New Jersey, on September 23, 1997.

MERCK & CO., INC.

By /s/  RAYMOND V. GILMARTIN
  ------------------------------------
         (Raymond V. Gilmartin)
  Chairman of the Board, President and
        Chief Executive Officer

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Celia A. Colbert and Mary M. McDonald, and each of them, as his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and all documents relating thereto, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing necessary or advisable to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

             SIGNATURE                               TITLE                         DATE
------------------------------------  ------------------------------------  -------------------

      /s/ RAYMOND V. GILMARTIN        Chairman of the Board, President,     September 23, 1997
------------------------------------    Chief Executive Officer and
       (Raymond V. Gilmartin)           Director (principal executive
                                        officer)

         /s/ JUDY C. LEWENT           Senior Vice President and Chief       September 23, 1997
------------------------------------    Financial Officer (principal
          (Judy C. Lewent)              financial officer)

        /s/ PETER E. NUGENT           Vice President and Controller         September 23, 1997
------------------------------------    (principal accounting officer)
         (Peter E. Nugent)

    /s/ H. BREWSTER ATWATER, JR.      Director                              September 23, 1997
------------------------------------
     (H. Brewster Atwater, Jr.)

          /s/ DEREK BIRKIN            Director                              September 23, 1997
------------------------------------
           (Derek Birkin)

      /s/ LAWRENCE A. BOSSIDY         Director                              September 23, 1997
------------------------------------
       (Lawrence A. Bossidy)


             SIGNATURE                               TITLE                         DATE
------------------------------------  ------------------------------------  -------------------

        /s/ WILLIAM G. BOWEN          Director                              September 23, 1997
------------------------------------
         (William G. Bowen)

       /s/ JOHNNETTA B. COLE          Director                              September 23, 1997
------------------------------------
        (Johnnetta B. Cole)

       /s/ CAROLYNE K. DAVIS          Director                              September 23, 1997
------------------------------------
        (Carolyne K. Davis)

         /s/ LLOYD C. ELAM            Director                              September 23, 1997
------------------------------------
          (Lloyd C. Elam)

     /s/ CHARLES E. EXLEY, JR.        Director                              September 23, 1997
------------------------------------
      (Charles E. Exley, Jr.)

       /s/ WILLIAM N. KELLEY          Director                              September 23, 1997
------------------------------------
        (William N. Kelley)

       /s/ EDWARD M. SCOLNICK         Director                              September 23, 1997
------------------------------------
        (Edward M. Scolnick)

        /s/ SAMUEL O. THIER           Director                              September 23, 1997
------------------------------------
         (Samuel O. Thier)

                                      Director
------------------------------------
       (Dennis Weatherstone)


EXHIBIT INDEX

EXHIBIT NUMBER                                        DESCRIPTION
--------------        ----------------------------------------------------------------------------
       1         --   Form of Underwriting Agreement.
       4(b)      --   Form of First Supplemental Indenture between the Company and First Trust of
                      New York, National Association, as Trustee.
       5         --   Opinion and Consent of Mary M. McDonald, Esq.
      23(a)      --   Consent of Arthur Andersen LLP.
      23(b)      --   Consent of Counsel (included in Exhibit 5).
      24         --   Power of Attorney (included in the signature page hereto).
      25         --   Statement of Eligibility and Qualification on Form T-1 under the Trust
                      Indenture Act of 1939, as amended, of First Trust of New York, National
                      Association.





Exhibit 1

S&C Draft of September 11, 1997

MERCK & CO., INC.

Debt Securities

Underwriting Agreement

_________ ___, 1997

TO THE REPRESENTATIVES OF THE
SEVERAL UNDERWRITERS NAMED IN THE
RESPECTIVE PRICING AGREEMENTS
HEREINAFTER DESCRIBED.

Dear Sir or Madame:

From time to time Merck & Co., Inc., a New Jersey corporation (the "Company"), proposes to enter into one or more Pricing Agreements (each a "Pricing Agreement") in the form of Annex I hereto, with such additions and deletions as the parties thereto may determine, and, subject to the terms and conditions stated herein and therein, to issue and sell to the firms named in Schedule I to the applicable Pricing Agreement (such firms constituting the "Underwriters" with respect to such Pricing Agreement and the securities specified therein) certain of its debt securities (the "Securities") specified in Schedule II to such Pricing Agreement (with respect to such Pricing Agreement,the "Designated Securities").

The terms and rights of any particular issuance of Designated Securities shall be as specified in the Pricing Agreement relating thereto and in or pursuant to the indenture (the "Indenture") identified in such Pricing Agreement.

1. Particular sales of Designated Securities may be made from time to time to the Underwriters of such Securities, for whom the firms designated as representatives of the Underwriters of such Securities in the Pricing Agreement relating thereto will act as representatives (the "Representatives"). The term "Representatives" also refers to a single firm acting as sole representative of the Underwriters and to Underwriters who act without any firm being designated as their representative. This Underwriting Agreement shall not be construed as an obligation of the Company to sell any of the Securities or as an obligation of any of the Underwriters to purchase the Securities. The obligation of the Company to issue and sell any of the Securities and the obligation of any of the Underwriters to


purchase any of the Securities shall be evidenced by the Pricing Agreement with respect to the Designated Securities specified therein. Each Pricing Agreement shall specify the aggregate principal amount of such Designated Securities, the initial public offering price of such Designated Securities, the purchase price to the Underwriters of such Designated Securities, the names of the Underwriters of such Designated Securities, the names of the Representatives of such Underwriters and the principal amount of such Designated Securities to be purchased by each Underwriter and shall set forth the date, time and manner of delivery of such Designated Securities and payment therefor. The Pricing Agreement shall also specify (to the extent not set forth in the Indenture and the registration statement and prospectus with respect thereto) the terms of such Designated Securities. A Pricing Agreement shall be in the form of an executed writing (which may be in counterparts), and may be evidenced by an exchange of telegraphic communications or any other rapid transmission device designed to produce a written record of communications transmitted. The obligations of the Underwriters under this Agreement and each Pricing Agreement shall be several and not joint.

2. The Company represents and warrants to, and agrees with, each of the Underwriters that:

(a) Two registration statements on Form S-3 (File Nos. 33-60322 and 333-______ )(together, the "Initial Registration Statement") in respect of the Securities have been filed with the Securities and Exchange Commission (the "Commission"); such Initial Registration Statement and any post-effective amendment thereto, each in the form heretofore delivered or to be delivered to the Representatives and, excluding exhibits to such registration statement, but including all documents incorporated by reference in the prospectus contained in the latest registration statement, to the Representatives for each of the other Underwriters, have been declared effective by the Commission in such form; other than a Registration Statement, if any, increasing the size of the offering (a "Rule 462(b) Registration Statement"), filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the "Act"), which became effective upon filing, no other document with respect to the Initial Registration Statement or document incorporated by reference therein has heretofore been filed or transmitted for filing with the Commission (other than the prospectuses filed pursuant to Rule 424(b) of the rules and regulations of

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the Commission under the Act), each in the form heretofore delivered to the Representatives on or prior to the date hereof; and no stop order suspending the effectiveness of the Initial Registration Statement, any post-effective amendment thereto or the Rule 462(b) Registration Statement, if any, has been issued and no proceeding for that purpose has been initiated or threatened by the Commission (any preliminary prospectus included in the Initial Registration Statement or filed with the Commission pursuant to Rule 424(a) of the rules and regulations of the Commission under the Act, being hereinafter called a "Preliminary Prospectus"; the various parts of the Initial Registration Statement and the Rule 462(b) Registration Statement, if any, including all exhibits thereto and the documents incorporated by reference in the prospectus contained in the Initial Registration Statement at the time such part of the registration statement became effective but excluding Form T-1, each as amended at the time such part of the registration statement became effective or such part of the Rule 462(b) Registration Statement, if any, became or hereafter becomes effective, being hereinafter called the "Registration Statement"; the prospectus relating to the Securities, in the form in which it has most recently been filed, or transmitted for filing, with the Commission on or prior to the date of this Agreement, being hereinafter called the "Prospectus"; any reference herein to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to the applicable form under the Act, as of the date of such Preliminary Prospectus or Prospectus, as the case may be; any reference to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents filed after the date of such Preliminary Prospectus or Prospectus, as the case may be, under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and incorporated by reference in such Preliminary Prospectus or Prospectus, as the case may be; any reference to any amendment to the Registration Statement shall be deemed to refer to and include any annual report of the Company filed pursuant to Section 13(a) or 15(d) of the Exchange Act after the effective date of the Registration Statement that is incorporated by reference in the Registration Statement; and any reference to the Prospectus as amended or supplemented shall be deemed to refer to the Prospectus as amended or

-3-

supplemented in relation to the applicable Designated Securities in the form in which it is filed with the Commission pursuant to Rule 424(b) under the Act in accordance with Section 5(a) hereof, including any documents incorporated by reference therein as of the date of such filing);

(b) The documents incorporated by reference in the Prospectus, when they became effective or were filed with the Commission, as the case may be, conformed in all material respects to the requirements of the Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder, and none of such documents contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading; and any further documents so filed and incorporated by reference in the Prospectus or any further amendment or supplement thereto, when such documents become effective or are filed with the Commission, as the case may be, will conform in all material respects to the requirements of the Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; provided, however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter of Designated Securities through the Representatives expressly for use in the Prospectus as amended or supplemented relating to such Securities;

(c) The Registration Statement and the Prospectus conform, and any further amendments or supplements to the Registration Statement or the Prospectus will conform, in all material respects to the requirements of the Act and the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act") and the rules and regulations of the Commission thereunder and do not and will not, as of the applicable effective date as to the Registration Statement and any amendment thereto and as of the applicable filing date as to the Prospectus and any amendment or supplement thereto, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; provided,

-4-

however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter of Designated Securities through the Representatives expressly for use in the Prospectus as amended or supplemented relating to such Securities;

(d) Neither the Company nor any of its subsidiaries has sustained since the date of the latest audited financial statements included or incorporated by reference in the Prospectus any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus; and, since the respective dates as of which information is given in the Registration Statement and the Prospectus, there has not been any material change in the consolidated capital stock or any material increase in the consolidated long-term debt of the Company and its subsidiaries or any material adverse change, or any development involving a prospective material adverse change, in or affecting the general affairs, management, financial position, stockholders' equity or results of operations of the Company and its subsidiaries taken as a whole, otherwise than as set forth or contemplated in the Prospectus;

(e) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of New Jersey, with power and authority (corporate and other) to own its properties and conduct its business as described in the Prospectus;

(f) Each of the following subsidiaries of the Company: [MSD Ireland (Holdings) S.A., Merck Sharp & Dohme (Ireland) Ltd., MSD Overseas Finance, Merck Sharp & Dohme Quimica de Puerto Rico, Inc., Merck Sharp & Dohme Limited, Merck Sharp & Dohme (Italia) S.p.A., Merck Sharp & Dohme B.V., Laboratoires Merck Sharp & Dohme - Chibret SNC, Banyu Pharmaceutical Co., Ltd., Financiere MSD S.A.S., MSD Overseas Manufacturing Co. and Merck Sharp & Dohme Overseas Finance]* has been duly incorporated, and is validly existing as a corporation in good standing under the laws of the


* Confirm which subsidiaries currently should be covered.

-5-

jurisdiction of its incorporation and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or the ownership or leasing of its property requires such qualification, except where failure to qualify would not have a materially adverse effect upon the Company and its consolidated subsidiaries taken as a whole;

(g) The Securities have been duly authorized, and, when Designated Securities are issued and delivered pursuant to this Agreement and the Pricing Agreement with respect to such Designated Securities, such Designated Securities will have been duly executed, authenticated, issued and delivered and will constitute valid and legally binding obligations of the Company entitled to the benefits provided by the Indenture, which will be substantially in the form filed as an exhibit to the Registration Statement; the Indenture has been duly authorized and duly qualified under the Trust Indenture Act and, at the Time of Delivery for such Designated Securities (as defined in Section 4 hereof), the Indenture will constitute a valid and legally binding instrument, enforceable in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors' rights and to general equity principles; and the Indenture conforms, and the Designated Securities will conform, to the descriptions thereof contained in the Prospectus as amended or supplemented with respect to such Designated Securities;

(h) The issue and sale of the Securities and the compliance by the Company with all of the provisions of the Securities, the Indenture, this Agreement and any Pricing Agreement, and the consummation of the transactions herein and therein contemplated will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any of the property or assets of the Company or any of its subsidiaries pursuant to the terms of any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its

-6-

subsidiaries is subject, nor will such action result in any violation of the provisions of the Certificate of Incorporation or By-laws of the Company or any statute, order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Securities or the consummation by the Company of the transactions contemplated by this Agreement or any Pricing Agreement or the Indenture, except such as have been, or will have been prior to the Time of Delivery, obtained under the Act and the Trust Indenture Act and such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Securities by the Underwriters; and

(i) There are no legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or of which any property of the Company or any of its subsidiaries is the subject, other than as set forth in the Prospectus and other than litigation incident to the kind of business conducted by the Company and its subsidiaries which, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a material adverse effect on the consolidated financial position, stockholders' equity or results of operation of the Company and its subsidiaries; and, to the best of the Company's knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others.

3. Upon the execution of the Pricing Agreement applicable to any Designated Securities and authorization by the Representatives of the release of such Designated Securities, the several Underwriters propose to offer such Designated Securities for sale upon the terms and conditions set forth in the Prospectus as amended or supplemented.

4. Designated Securities to be purchased by each Underwriter pursuant to the Pricing Agreement relating thereto, in definitive form to the extent practicable, and in such authorized denominations and registered in such names as the Representatives may request upon at least forty-eight hours' prior notice to the Company, shall be

-7-

delivered by or on behalf of the Company to the Representatives for the account of such Underwriter, against payment by such Underwriter or on its behalf of the purchase price therefor by wire transfer or by certified or official bank check or checks, payable to the order of the Company (unless provided otherwise in the Pricing Agreement) in the funds specified in such Pricing Agreement, all at the place and time and date specified in such Pricing Agreement or at such other place and time and date as the Representatives and the Company may agree upon in writing, such time and date being herein called the "Time of Delivery" for such Securities.

5. The Company agrees with each of the Underwriters of any Designated Securities:

(a) To prepare the Prospectus as amended and supplemented in relation to the applicable Designated Securities in a form approved by the Representatives and to file such Prospectus pursuant to Rule 424(b) under the Act not later than the Commission's close of business on the second business day following the execution and delivery of the Pricing Agreement relating to the applicable Designated Securities or, if applicable, such earlier time as may be required by Rule 424(b); to make no further amendment or any supplement to the Registration Statement or Prospectus as amended or supplemented after the date of the Pricing Agreement relating to such Securities and prior to the Time of Delivery for such Securities which shall be disapproved by the Representatives for such Securities promptly after reasonable notice thereof; to advise the Representatives promptly of any such amendment or supplement after such Time of Delivery and furnish the Representatives with copies thereof; to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act for so long as the delivery of a prospectus is required in connection with the offering or sale of such Securities, and during such same period to advise the Representatives, promptly after it receives notice thereof, of the time when any amendment to the Registration Statement has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed with the Commission, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any prospectus relating to the Securities, of the suspension of the qualification of

-8-

such Securities for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statement or Prospectus or for additional information; and, in the event of the issuance of any such stop order or of any such order preventing or suspending the use of any prospectus relating to the Securities or suspending any such qualification, to use promptly its best efforts to obtain its withdrawal;

(b) Promptly from time to time to take such action as the Representatives may reasonably request to qualify such Securities for offering and sale under the securities laws of such jurisdictions as the Representatives may request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of such Securities, provided that in connection therewith the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction;

(c) Prior to 10:00 a.m., New York City time, on the New York Business Day next succeeding the date of this Agreement and from time to time, to furnish the Underwriters with copies of the Prospectus in New York City as amended or supplemented in such quantities as the Representatives may reasonably request, and, if the delivery of a prospectus is required at any time in connection with the offering or sale of the Securities and if at such time any event shall have occurred as a result of which the Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made when such Prospectus is delivered, not misleading, or, if for any other reason it shall be necessary during such same period to amend or supplement the Prospectus or to file under the Exchange Act any document incorporated by reference in the Prospectus in order to comply with the Act, the Exchange Act or the Trust Indenture Act, to notify the Representatives and upon their request to file such document and to prepare and furnish without charge to each Underwriter and to any dealer in securities as many copies as the Representatives may from time to time reasonably

-9-

request of an amended Prospectus or a supplement to the Prospectus which will correct such statement or omission or effect such compliance;

(d) To make generally available to its securityholders as soon as practicable, but in any event not later than eighteen months after the effective date of the Registration Statement (as defined in Rule 158(c)), an earnings statement of the Company and its subsidiaries (which need not be audited) complying with Section 11(a) of the Act and the rules and regulations of the Commission thereunder (including, at the option of the Company, Rule 158); and

(e) During the period beginning from the date of the Pricing Agreement for such Designated Securities and continuing to and including the earlier of (i) the termination of trading restrictions for such Designated Securities, as notified to the Company by the Representatives and (ii) the Time of Delivery for such Designated Securities, not to offer, sell, contract to sell or otherwise dispose of any debt securities of the Company which mature more than one year after such Time of Delivery and which are substantially similar to such Designated Securities, without the prior written consent of the Representatives.

(f) If the Company elects to rely upon Rule 462(b), the Company shall file a Rule 462(b) Registration Statement with the Commission in compliance with Rule 462(b) by 10:00 P.M., Washington, D.C. time, on the date of this Agreement, and the Company shall at the time of filing either pay to the Commission the filing fee for the Rule 462(b) Registration Statement or give irrevocable instructions for the payment of such fee pursuant to Rule 111(b) under the Act.

6. The Company covenants and agrees with the several Underwriters that the Company will pay or cause to be paid the following: (i) the fees, disbursements and expenses of the Company's counsel and accountants in connection with the registration of the Securities under the Act and all other expenses in connection with the preparation, printing and filing of the Registration Statement, any Preliminary Prospectus and the Prospectus and amendments and supplements thereto and the mailing and delivering of copies thereof to the Underwriters and dealers; (ii) the cost of printing or producing any Agreement among Underwriters, this

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Agreement, any Pricing Agreement, any Indenture, any Blue Sky and Legal Investment Memoranda and any other documents in connection with the offering, purchase, sale and delivery of the Securities; (iii) all expenses in connection with the qualification of the Securities for offering and sale under state securities laws as provided in Section 5(b) hereof, including the fees and disbursements of counsel for the Underwriters in connection with such qualification and in connection with the Blue Sky and legal investment surveys;
(iv) any fees charged by securities rating services for rating the Securities;
(v) any filing fees incident to any required review by the National Association of Securities Dealers, Inc. of the terms of the sale of the Securities; (vi) the cost of preparing the Securities; (vii) the fees and expenses of any Trustee and any agent of any Trustee and the fees and disbursements of counsel for any Trustee in connection with any Indenture and the Securities; and (viii) all other costs and expenses incident to the performance of its obligations hereunder which are not otherwise specifically provided for in this Section; but the Company shall not in any event be liable to any of the Underwriters for damages on account of loss of anticipated profits from the sale by them of the Securities. It is understood, however, that, except as provided in this Section,
Section 8 and Section 11 hereof, the Underwriters will pay all of their own costs and expenses, including the fees of their counsel, transfer taxes on resale of any of the Securities by them, and any advertising expenses connected with any offers they may make.

7. The obligations of the Underwriters of any Designated Securities under the Pricing Agreement relating to such Designated Securities shall be subject, in the discretion of the Representatives, to the condition that all representations and warranties and other statements of the Company in or incorporated by reference in the Pricing Agreement relating to such Designated Securities are, at and as of the Time of Delivery for such Designated Securities, true and correct, the condition that the Company shall have performed all of its obligations hereunder theretofore to be performed, and the following additional conditions:

(a) The Prospectus as amended or supplemented in relation to the applicable Designated Securities shall have been filed with the Commission pursuant to Rule 424(b) within the applicable time period prescribed for such filing by the rules and regulations under the Act and in accordance with Section 5(a) hereof; if the Company has elected to rely upon Rule
462(b), the Rule

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462(b) Registration Statement shall have become effective by 10:00 P.M., Washington, D.C. time, on the date of this Agreement; no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to the Representatives' reasonable satisfaction;

(b) Counsel for the Underwriters shall have furnished to the Representatives such opinion or opinions, dated the Time of Delivery for such Designated Securities, with respect to the incorporation of the Company, the validity of the Indenture, the Designated Securities, the Registration Statement, the Prospectus as amended or supplemented and other related matters as the Representatives may reasonably request, and such counsel shall have received such papers and information as they may reasonably request to enable them to pass upon such matters;

(c) Mary M. McDonald, Esq., Senior Vice President and General Counsel to the Company (or such other person who shall be General Counsel to the Company at such Time of Delivery), shall have furnished to the Representatives his written opinion, dated the Time of Delivery for such Designated Securities, in form and substance satisfactory to the Representatives, to the effect that:

(i) The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the State of New Jersey and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or the ownership or leasing of property requires such qualification, except where failure to qualify would not have a materially adverse effect upon the Company and its consolidated subsidiaries taken as a whole;

(ii) Each of the following subsidiaries of the Company: [MSD Ireland (Holdings) S.A., Merck Sharp & Dohme (Ireland) Ltd., MSD Overseas Finance, Merck Sharp & Dohme Quimica de Puerto Rico, Inc., Merck Sharp & Dohme Limited, Merck Sharp & Dohme (Italia) S.p.A., Merck Sharp & Dohme B.V.,

-12-

Laboratoires Merck Sharp & Dohme - Chibret SNC, Banyu Pharmaceutical Co., Ltd., Financiere MSD S.A.S., MSD Overseas Manufacturing Co. and Merck Sharp & Dohme Overseas Finance]** has been duly incorporated, and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or the ownership or leasing of its property requires such qualification, except where failure to qualify would not have a materially adverse effect upon the Company and its consolidated subsidiaries taken as a whole;

(iii) To the best of such counsel's knowledge, there are no legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or of which any property of the Company or any of its subsidiaries is the subject, other than as set forth in the Prospectus and other than litigation or proceedings which individually are not material to the Company and its subsidiaries taken as a whole; to the best of such counsel's knowledge, no such proceedings are threatened by governmental authorities or others; and such counsel has not received notice that any such proceedings are contemplated by governmental authorities;

(iv) This Agreement and the Pricing Agreement with respect to the Designated Securities have been duly authorized, executed and delivered by the Company;

(v) The Designated Securities have been duly authorized, executed, authenticated, issued and delivered and constitute valid and legally binding obligations of the Company entitled to the benefits provided by the Indenture; and the Designated Securities and the Indenture conform to the descriptions thereof in the Prospectus as amended or supplemented;

(vi) The Indenture has been duly authorized, executed and delivered by the Company and duly qualified under the Trust Indenture Act and, at


** Note: Conform to Sec. 2(f).

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the Time of Delivery for such Designated Securities (as defined in
Section 4 hereof), the Indenture will constitute a valid and legally binding instrument, enforceable in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors' rights and to general equity principles;

(vii) The issue and sale of the Designated Securities and the compliance by the Company with all of the provisions of the Designated Securities, the Indenture, this Agreement and the Pricing Agreement with respect to the Designated Securities will not conflict with or result in a breach of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any of the property or assets of the Company or any of its subsidiaries pursuant to the terms of, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument known to such counsel to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject, nor will such action result in any violation of the provisions of the Certificate of Incorporation, as amended, or the By-Laws of the Company or any statute, order, rule or regulation known to such counsel of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties; and no consent, approval, authorization, order, registration or qualification of or with any court or any such regulatory authority or other governmental body is required for the issue and sale by the Company of the Designated Securities or the execution and delivery and performance by the Company of this Agreement, the Pricing Agreement or the Indenture, except such as have been obtained under the Act and the Trust Indenture Act and such consents, approvals, authorizations, registrations or qualifications as may be required under State Securities or Blue Sky laws in connection with the purchase and

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distribution of the Designated Securities by the Underwriters;

(viii) The documents incorporated by reference in the Prospectus as amended or supplemented (other than the financial statements and related schedules therein, as to which such counsel need express no opinion), when they became effective or were filed with the Commission, as the case may be, complied as to form in all material respects with the requirements of the Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder; and such counsel has no reason to believe that any of such documents, when they became effective or were so filed, as the case may be, contained, in the case of a registration statement which became effective under the Act, an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, or, in the case of other documents which were filed under the Act or the Exchange Act with the Commission, an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made when such documents were so filed, not misleading; and

(ix) The Registration Statement and the Prospectus as amended or supplemented and any further amendments and supplements thereto made by the Company prior to the Time of Delivery for the Designated Securities (other than the financial statements and related schedules therein, as to which such counsel need express no opinion) comply as to form in all material respects with the requirements of the Act and the Trust Indenture Act and the rules and regulations thereunder; such counsel has no reason to believe that, as of its effective date, the Registration Statement or any further amendment thereto made by the Company prior to the Time of Delivery (other than the financial statements and related schedules therein, as to which such counsel need express no opinion) contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or that, as

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of its date, the Prospectus as amended or supplemented or any further amendment or supplement thereto made by the Company prior to the Time of Delivery (other than the financial statements and related schedules therein, as to which such counsel need express no opinion) contained an untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein, in light of the circumstances in which they were made, not misleading or that, as of the Time of Delivery, either the Registration Statement or the Prospectus as amended or supplemented or any further amendment or supplement thereto made by the Company prior to the Time of Delivery (other than the financial statements and related schedules therein, as to which such counsel need express no opinion) contains an untrue statement of a material fact or omits to state a material fact necessary to make the statements therein, in light of the circumstances in which they were made, not misleading; and such counsel does not know of any amendment to the Registration Statement required to be filed or any contracts or other documents of a character required to be filed as an exhibit to the Registration Statement or required to be incorporated by reference into the Prospectus as amended or supplemented or required to be described in the Registration Statement or the Prospectus as amended or supplemented which are not filed or incorporated by reference or described as required;

(d) On the date of the Pricing Agreement for such Designated Securities and at the Time of Delivery for such Designated Securities, the independent accountants of the Company who have certified the financial statements of the Company and its subsidiaries included or incorporated by reference in the Registration Statement shall have furnished to the Representatives a letter, dated the effective date of the Registration Statement or the date of the most recent report filed with the Commission containing financial statements and incorporated by reference in the Registration Statement, if the date of such report is later than such effective date, and a letter dated such Time of Delivery, respectively, to the effect set forth in Annex II hereto, and with respect to such letter dated such Time of Delivery, as to such other matters as the Representatives

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may reasonably request and in form and substance satisfactory to the Representatives;

(e)(i) Neither the Company nor any of its subsidiaries shall have sustained since the date of the latest financial statements included or incorporated by reference in the Prospectus as amended or supplemented any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Prospectus as amended or supplemented, and (ii) since the respective dates as of which information is given in the Prospectus as amended or supplemented there shall not have been any change in the consolidated capital stock (except for the issuance of shares of common stock pursuant to the Company's savings, incentive stock and executive incentive plans) or any increase in the consolidated long-term debt of the Company and its subsidiaries or any change, or any development involving a prospective change, in or affecting the general affairs, management, financial position, stockholders' equity or results of operations of the Company and its subsidiaries, otherwise than as set forth or contemplated in the Prospectus as amended or supplemented, the effect of which, in any such case described in Clause (i) or (ii), is in the judgment of the Representatives so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Designated Securities on the terms and in the manner contemplated in the Prospectus as amended or supplemented;

(f) On or after the date of the Pricing Agreement relating to the Designated Securities (i) no down-grading shall have occurred in the rating accorded the Company's debt securities by any "nationally recognized statistical rating organization," as that term is defined by the Commission for purposes of Rule 436(g)(2) under the Act and (ii) no such organization shall have publicly announced that it has under surveillance or review, with possible negative implications, its rating of any of the Company's debt securities;

(g) On or after the date of the Pricing Agreement relating to the Designated Securities there shall not have occurred any of the following:
(i) a suspension of trading of the Company's Common Stock by the Commission

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or the New York Stock Exchange precipitated by the announcement by the Company of a material adverse event with respect to the Company's business or financial position; (ii) a suspension or material limitation in trading in securities generally on the New York Stock Exchange; (iii) a general moratorium on commercial banking activities in New York declared by either Federal or New York State authorities; or (iv) the outbreak or escalation of hostilities involving the United States or the declaration by the United States of a national emergency or war, if the effect of any such event specified in this clause (iv) in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Designated Securities on the terms and in the manner contemplated by the Prospectus as amended and supplemented; and

(h) The Company shall have complied with the provisions of Section 5(c) hereof with respect to the furnishing of prospectuses on the New York Business Day next succeeding the date of this Agreement.

(i) The Company shall have furnished or caused to be furnished at the Time of Delivery for the Designated Securities a certificate or certificates of officers of the Company satisfactory to the Representatives as to the accuracy of the representations and warranties of the Company herein at and as of such Time of Delivery, as to the performance by the Company of all of its obligations hereunder to be performed at or prior to such Time of Delivery, as to the matters set forth in subsections (a) and (e) of this Section and as to such other matters as the Representatives may reasonably request.

8. (a) The Company will indemnify and hold harmless each Underwriter against any losses, claims, damages or liabilities, joint or several, to which such Underwriter may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, any preliminary prospectus supplement, the Registration Statement, the Prospectus as amended or supplemented and any other prospectus relating to the Securities, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein

-18-

a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such action or claim as such expenses are incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in any Preliminary Prospectus, any preliminary prospectus supplement, the Registration Statement, the Prospectus as amended or supplemented and any other prospectus relating to the Securities, or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by any Underwriter of Designated Securities through the Representatives expressly for use in the Prospectus as amended or supplemented relating to such Securities.

(b) Each Underwriter will indemnify and hold harmless the Company against any losses, claims, damages or liabilities to which the Company may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, any preliminary prospectus supplement, the Registration Statement, the Prospectus as amended or supplemented and any other prospectus relating to the Securities, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in any Preliminary Prospectus, any preliminary prospectus supplement, the Registration Statement, the Prospectus as amended or supplemented and any other prospectus relating to the Securities, or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives expressly for use therein; and will reimburse the Company for any legal or other expenses reasonably incurred by the Company in connection with investigating or defending any such action or claim as such expenses are incurred.

(c) Promptly after receipt by an indemnified party under subsection
(a) or (b) above of notice of the

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commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under such subsection, notify the indemnifying party in writing of the commencement thereof; but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to any indemnified party otherwise than under such subsection. In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such indemnified party under such subsection for any legal expenses of other counsel or any other expenses, in each case subsequently incurred by such indemnified party, in connection with the defense thereof other than reasonable costs of investigation.

(d) If the indemnification provided for in this Section 8 is unavailable to or insufficient to hold harmless an indemnified party under subsection (a) or (b) above in respect of any losses, claims, damages or liabilities (or actions in respect thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (or actions in respect thereof) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters of the Designated Securities on the other from the offering of the Designated Securities to which such loss, claim, damage or liability (or action in respect thereof) relates. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law or if the indemnified party failed to give the notice required under subsection (c) above, then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company on the one hand and the Underwriters of the Designated Securities on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities (or actions in respect thereof), as well as any

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other relevant equitable considerations. The relative benefits received by the Company on the one hand and such Underwriters on the other shall be deemed to be in the same proportion as the total net proceeds from such offering (before deducting expenses) received by the Company bear to the total underwriting discounts and commissions received by such Underwriters. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or such Underwriters on the other and the parties' relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this subsection (d) were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this subsection (d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions in respect thereof) referred to above in this subsection (d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this subsection (d), no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the applicable Designated Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The obligations of the Underwriters of Designated Securities in this subsection (d) to contribute are several in proportion to their respective underwriting obligations with respect to such Securities and not joint.

(e) The obligations of the Company under this Section 8 shall be in addition to any liability which the Company may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Act; and the obligations of the Underwriters under this Section 8 shall

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be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company and to each person, if any, who controls the Company within the meaning of the Act.

9. (a) If any Underwriter shall default in its obligation to purchase the Designated Securities which it has agreed to purchase under the Pricing Agreement relating to such Designated Securities, the Representatives may in their discretion arrange for themselves or another party or other parties to purchase such Designated Securities on the terms contained herein. If within thirty-six hours after such default by any Underwriter the Representatives do not arrange for the purchase of such Designated Securities, then the Company shall be entitled to a further period of thirty-six hours within which to procure another party or other parties satisfactory to the Representatives to purchase such Designated Securities on such terms. In the event that, within the respective prescribed period, the Representatives notify the Company that they have so arranged for the purchase of such Designated Securities, or the Company notifies the Representatives that it has so arranged for the purchase of such Designated Securities, the Representatives or the Company shall have the right to postpone the Time of Delivery for such Designated Securities for a period of not more than seven days, in order to effect whatever changes may thereby be made necessary in the Registration Statement or the Prospectus as amended or supplemented, or in any other documents or arrangements, and the Company agrees to file promptly any amendments or supplements to the Registration Statement or the Prospectus which in the opinion of the Representatives may thereby be made necessary. The term "Underwriter" as used in this Agreement shall include any person substituted under this Section with like effect as if such person had originally been a party to the Pricing Agreement with respect to such Designated Securities.

(b) If, after giving effect to any arrangements for the purchase of the Designated Securities of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided in subsection (a) above, the aggregate principal amount of such Designated Securities which remains unpurchased does not exceed one-eleventh of the aggregate principal amount of the Designated Securities, then the Company shall have the right to require each non-defaulting Underwriter to purchase the principal amount of Designated Securities which such Underwriter agreed to purchase under the Pricing Agreement relating to such

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Designated Securities and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the principal amount of Designated Securities which such Underwriter agreed to purchase under such Pricing Agreement) of the Designated Securities of such defaulting Underwriter or Underwriters for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

(c) If, after giving effect to any arrangements for the purchase of the Designated Securities of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided in subsection (a) above, the aggregate principal amount of Designated Securities which remains unpurchased exceeds one-eleventh of the aggregate principal amount of the Designated Securities, as referred to in subsection (b) above, or if the Company shall not exercise the right described in subsection (b) above to require non-defaulting Underwriters to purchase Designated Securities of a defaulting Underwriter or Underwriters, then the Pricing Agreement relating to such Designated Securities shall thereupon terminate, without liability on the part of any non-defaulting Underwriter or the Company, except for the expenses to be borne by the Company and the Underwriters as provided in Section 6 hereof and the indemnity and contribution agreements in Section 8 hereof; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

10. The respective indemnities, agreements, representations, warranties and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of any Underwriter or any controlling person of any Underwriter, or the Company, or any officer or director or controlling person of the Company, and shall survive delivery of and payment for the Securities.

11. If any Pricing Agreement shall be terminated pursuant to Section 9 hereof, the Company shall not then be under any liability to any Underwriter with respect to the Designated Securities covered by such Pricing Agreement except as provided in Section 6 and Section 8 hereof; but, if for any other reason Designated Securities are not delivered by or on behalf of the Company as provided herein, the Company will reimburse the Underwriters through the

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Representatives for all out-of-pocket expenses approved in writing by the Representatives, including fees and disbursements of counsel, reasonably incurred by the Underwriters in making preparations for the purchase, sale and delivery of such Designated Securities, but the Company shall then be under no further liability to any Underwriter with respect to such Designated Securities except as provided in Section 6 and Section 8 hereof.

12. In all dealings hereunder, the Representatives of the Underwriters of Designated Securities shall act on behalf of each of such Underwriters, and the parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter made or given by such Representatives jointly or by such of the Representatives, if any, as may be designated for such purpose in the Pricing Agreement.

All statements, requests, notices and agreements hereunder shall be in writing, and if to the Underwriters shall be delivered or sent by mail, telex or facsimile transmission to the address of the Representatives as set forth in the Pricing Agreement; and if to the Company shall be delivered or sent by mail, telex or facsimile transmission to the address of the Company set forth in the Registration Statement: Attention: Secretary; provided, however, that any notice to an Underwriter pursuant to Section 8 (c) hereof shall be delivered or sent by mail, telex or facsimile transmission to such Underwriter at its address set forth in its Underwriters' Questionnaire, or telex constituting such Questionnaire, which address will be supplied to the Company by the Representatives upon request. Any such statements, requests, notices or agreements shall take effect upon receipt thereof.

13. This Agreement and each Pricing Agreement shall be binding upon, and inure solely to the benefit of, the Underwriters, the Company and, to the extent provided in Section 8 and Section 10 hereof, the officers and directors of the Company and each person who controls the Company or any Underwriter, and their respective heirs, executors, administrators, successors and assigns, and no other person shall acquire or have any right under or by virtue of this Agreement or any such Pricing Agreement. No purchaser of any of the Securities from any Underwriter shall be deemed a successor or assign by reason merely of such purchase.

14. Time shall be of the essence of each Pricing Agreement. As used herein, "business day" shall mean any

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day when the Commission's office in Washington, D.C. is open for business.

15. THIS AGREEMENT AND EACH PRICING AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

16. This Agreement and each Pricing Agreement may be executed by any one or more of the parties hereto and thereto in any number of counterparts, each of which shall be deemed to be an original, but all such respective counterparts shall together constitute one and the same instrument.

Very truly yours,

MERCK & CO., INC.

By:___________________________
Name:
Title:

Accepted as of the date hereof:


(Goldman, Sachs & Co.)

J.P. MORGAN SECURITIES INC.

By:___________________________
Name:
Title:

MORGAN STANLEY & CO. INCORPORATED

By:___________________________
Name:
Tile:

-25-

Exhibit 4(b)

Draft of August 20, 1997


MERCK & CO., INC.

TO

FIRST TRUST OF NEW YORK,
NATIONAL ASSOCIATION
as Trustee


First Supplemental Indenture

Dated as of ______, 1997

to

Indenture

Dated as of April 1, 1991




FIRST SUPPLEMENTAL INDENTURE dated as of ______, 1997 (the "First Supplemental Indenture") between MERCK & CO., INC., a corporation duly organized and existing under the laws of the State of New Jersey (the "Company"), having its principal office at One Merck Drive, Whitehouse Station, New Jersey 08889 and FIRST TRUST OF NEW YORK, NATIONAL ASSOCIATION, a national banking association duly organized and existing under the laws of the United States, as Trustee (the "Trustee").

R E C I T A L S

The Company has heretofore executed and delivered to MORGAN GUARANTY TRUST COMPANY OF NEW YORK (the "Predecessor Trustee") an Indenture, dated as of April 1, 1991 (herein called the "Indenture") between the Company and the Predecessor Trustee. All terms used in this First Supplemental Indenture which are defined in the Indenture shall have the same meanings assigned to them in the Indenture.

The Trustee is the successor to the Predecessor Trustee under the Indenture.

Section 901(5) of the Indenture provides that, without the consent of any Holders, the Company, when authorized by a Board Resolution, and the Trustee, at any time and from time to time, may enter into one or more indentures supplemental thereto, in form satisfactory to the Trustee, to add to, change or eliminate any of the provisions of the Indenture in respect of one or more series of Securities, provided that any such addition, change or elimination (A) shall neither (i) apply to any Security of any series created prior to the execution of such supplemental indenture and entitled to the benefit of such provision nor (B) modify the rights of the Holder of any such Security with respect to such provision or (ii) shall become effective only when there is no such Security Outstanding.

Section 901(9) of the Indenture provides that, without the consent of any Holders, the Company, when authorized by a Board Resolution, and the Trustee, at any time and from time to time, may enter into one or more indentures supplemental thereto, in form satisfactory to the Trustee, to cure any ambiguity, to correct or supplement any provision in the Indenture which may be defective or inconsistent with any other provision therein, or to make any other provisions with respect to matters or questions arising under the Indenture, provided that such action shall not adversely affect the interests of the Holders of Securities of any series in any material respect.

The Company has delivered to the Trustee an Opinion of Counsel pursuant to Sections 102 and 903 of the Indenture stating that the execution of this First Supplemental Indenture is authorized or permitted by the Indenture.

All things necessary to make this First Supplemental Indenture a valid agreement of the Company, in accordance with its terms, have been done.

NOW, THEREFORE, for and in consideration of the premises and the covenants contained in this First Supplemental Indenture, the parties hereto hereby agree, for

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the equal and proportionate benefit of all Holders of the Securities of any series created on or after the date hereof as follows:

SECTION 1. Section 301 of the Indenture is hereby amended by deleting Section 301(9) and inserting in its place the following:

"(9) if other than denominations of $1,000 and any integral multiple thereof, the denominations in which Securities of the series shall be issuable;"

SECTION 2. Section 302 of the Indenture is hereby amended by deleting the last sentence and inserting the following in its place:

"In the absence of any such provisions with respect to the Securities of any series created on or after the date of the First Supplemental Indenture, the Securities of such series shall be issuable in denominations of $1,000 and any integral multiple thereof."

SECTION 3. The provisions and benefit of this First Supplemental Indenture shall not be effective with respect to Securities of any series created prior to the date hereof.

SECTION 4. If any provision hereof limits, qualifies or conflicts with another provision hereof which is required to be included in this First Supplemental Indenture by any of the provisions of the Trust Indenture Act, such required provision shall control.

SECTION 5. In case any provision in this First Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality, and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

SECTION 6 . Nothing in this First Supplemental Indenture, express or implied, shall give to any Person, other than the parties hereto and their successors under the Indenture and the Holders of the Securities, any benefit or any legal or equitable right, remedy or claim under this First Supplemental Indenture.

SECTION 7. This First Supplemental Indenture supplements the Indenture and shall be a part and subject to all the terms thereof. Except as supplemented hereby, the Indenture shall continue in full force and effect.

SECTION 8. This First Supplemental Indenture may be executed in any number of counterparts, each of which as so executed shall be deemed to be an original, but all such counterparts shall together constitute but one and the same instrument.

SECTION 9. This First Supplemental Indenture shall be governed by and construed in accordance with the laws of the State of New York.

-2-

IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental Indenture to be duly executed, and their respective corporate seals to be hereunto affixed and attested, all as of the day and year first above written.

MERCK & CO., INC.

By_____________________________
Name:
Title:

Attest:


FIRST TRUST OF NEW YORK,
NATIONAL ASSOCIATION,
as Trustee

By_____________________________
Name:
Title:

Attest:


-3-

STATE OF NEW JERSEY                 )
                                    )  ss.:
COUNTY OF _______________           )

On the ____ day of ______, 1997 before me personally came ____________________________, to me known, who, being by me duly sworn, did depose and say that he or she is the _______________________ of Merck & Co, Inc., one of the corporations described in and which executed the foregoing instrument; that he or she knows the seal of said corporation; that the seal affixed to said instrument is such corporate seal; that it was so affixed by authority of the Board of Directors of said corporation, and that he or she signed his or her name thereto by like authority.


STATE OF NEW YORK             )
                              )  ss.:
COUNTY OF NEW YORK            )

On the ____ day of ____ __, 1997 before me personally came _____________________________, to me known, who, being by me duly sworn, did depose and say that he or she is _________________________ of First Trust of New York, National Association, one of the corporations described in and which executed the foregoing instrument; that he or she knows the seal of said corporation; that the seal affixed to said instrument is such corporate seal; that it was so affixed by authority of the Board of Directors of said corporation, and that he or she signed his or her name thereto by like authority.


-4-

Exhibit 5

MERCK & CO., INC.
ONE MERCK DRIVE
WHITEHOUSE STATION, NJ 08889-0100

September 25, 1997

Merck & Co., Inc.
One Merck Drive
Whitehouse Station, NJ 08889-0100

Ladies and Gentlemen:

In connection with the registration under the Securities Act of 1933, as amended (the "Act"), of $1,500,000,000 aggregate principal amount of debt securities (the "Securities") of Merck & Co., Inc., a New Jersey corporation (the "Company"), I, as Senior Vice President and General Counsel of the Company, or attorneys under my general supervision, have examined such corporate records, certificates and other documents and such questions of law as I have considered necessary or appropriate for the purposes of this opinion.

Upon the basis of such examination, I advise you that, in my opinion:

1. The Company has been duly incorporated and is an existing corporation in good standing under the laws of the state of New Jersey.

2. When the Registration Statement has become effective under the Act, the terms of the Securities and of their issue and sale have been duly established in conformity with the Indenture relating to the Securities so as not to violate any applicable law or agreement or instrument then binding on the Company, and the Securities have been duly executed and authenticated in accordance with such Indenture and issued and sold as contemplated in the Registration Statement, the Securities will constitute valid and binding obligations of the Company, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium, and similar laws of general applicability relating to or affecting creditors' rights and to general equity principles.

I hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to me under the heading "Validity of Debt Securities" in the Prospectus. In giving such consent, I do not thereby admit that I am in the category of persons whose consent is required under
Section 7 of the Act.

Very truly yours,

/s/  Mary M. McDonald
Senior Vice President and General Counsel


EXHIBIT 23(a)

CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

As independent public accountants, we hereby consent to the incorporation by reference in this Form S-3 Registration Statement of our report dated January 28, 1997 included in and incorporated by reference in Merck & Co., Inc.'s Annual Report on Form 10-K, for the fiscal year ended December 31, 1996, as amended by Form 10-K/A dated June 16, 1997 and to all references to our Firm included in or made a part of this Registration Statement.

ARTHUR ANDERSEN LLP

Roseland, N.J.

September 24, 1997


Exhibit 25

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D. C. 20549

FORM T - 1

STATEMENT OF ELIGIBILITY UNDER THE TRUST
INDENTURE ACT OF 1939 OF A CORPORATION
DESIGNATED TO ACT AS TRUSTEE

CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY
OF A TRUSTEE PURSUANT TO SECTION 305 (b) (2) _________

FIRST TRUST OF NEW YORK, NATIONAL ASSOCIATION (Exact name
of trustee as specified in its charter)

13-3781471
(I. R. S. Employer
Identification No.)

100 Wall Street, New York, NY 10005
(Address of principal executive offices) (Zip Code)

FOR INFORMATION, CONTACT:
Dennis Calabrese, President

First Trust of New York, National Association 100 Wall Street, 16th Floor New York, NY 10005 Telephone: (212) 361-2506

MERCK & CO., INC.
(Exact name of obligor as specified in its charter)

New Jersey                                                  22-1109110
(State or other jurisdiction of                             (I. R. S. Employer
incorporation or organization)                              Identification No.)

Merck & Co., Inc.
One Merck Drive
Whitehouse Station, New Jersey                              08889

(Address of principal executive offices)                    (Zip Code)

MEDIUM-TERM NOTES, SERIES C


Item 1. GENERAL INFORMATION.

Furnish the following information as to the trustee - -

(a) Name and address of each examining or supervising authority to which it is subject.

      Name                                Address
      ----                                -------
Comptroller of the Currency               Washington, D. C.

(b) Whether it is authorized to exercise corporate trust powers.

Yes.

Item 2. AFFILIATIONS WITH THE OBLIGOR.

If the obligor is an affiliate of the trustee, describe each such affiliation.

None.

Item 16. LIST OF EXHIBITS.

Exhibit 1. Articles of Association of First Trust of New York, National Association, incorporated herein by reference to Exhibit 1 of Form T-1, Registration No. 33-83774.

Exhibit 2. Certificate of Authority to Commence Business for First Trust of New York, National Association, incorporated herein by reference to Exhibit 2 of Form T-1, Registration No. 33-83774.

Exhibit 3. Authorization of the Trustee to exercise corporate trust powers for First Trust of New York, National Association, incorporated herein by reference to Exhibit 3 of Form T-1, Registration No. 33-83774.

Exhibit 4. By-Laws of First Trust of New York, National Association.

Exhibit 5. Not applicable.

Exhibit 6. Consent of First Trust of New York, National Association, required by Section 321(b) of the Act, incorporated herein by reference to Exhibit 6 of Form T-1, Registration No. 33-83774.

Exhibit 7. Report of Condition of First Trust of New York, National Association, as of the close of business on June 30, 1997, published pursuant to law or the requirements of its supervising or examining authority.


Exhibit 8. Not applicable.

Exhibit 9. Not applicable.

SIGNATURE

Pursuant to the requirements of the Trust Indenture Act of 1939, as amended, the trustee, First Trust of New York, National Association, a national banking association organized and existing under the laws of the United States, has duly caused this statement of eligibility to be signed on its behalf by the undersigned, thereunto duly authorized, all in The City of New York, and State of New York, on the 22nd day of September, 1997.

FIRST TRUST OF NEW YORK,
NATIONAL ASSOCIATION

By: /s/ Catherine F. Donohue
    -----------------------------------
      Catherine F. Donohue
      Vice President


EXHIBIT 4

FIRST TRUST OF NEW YORK,
NATIONAL ASSOCIATION

BYLAWS

ARTICLE I
Meetings of Shareholders

Section 1.1. Annual Meeting. The annual meeting of the shareholders, for the election of directors and the transaction of other business, shall be held at a time and place as the Chairman or President may designate. Notice of such meeting shall be given at least ten days prior to the date thereof, to each shareholder of the Association. If, for any reason, an election of directors is not made on the designated day, the election shall be held on some subsequent day, as soon thereafter as practicable, with prior notice thereof.

Section 1.2. Special Meetings. Except as otherwise specially provided by law, special meetings of the shareholders may be called for any purpose, at any time by a majority of the board of directors, or by any shareholder or group of shareholders owning at least ten percent of the outstanding stock. Every such special meeting, unless otherwise provided by law, shall be called upon not less than ten days prior notice stating the purpose of the meeting.

Section 1.3. Nominations for Directors. Nominations for election to the board of directors may be made by the board of directors or by any shareholder.

Section 1.4. Proxies. Shareholders may vote at any meeting of the shareholders by proxies duly authorized in writing. Proxies shall be valid only for one meeting and any adjournments of such meeting and shall be filed with the records of the meeting.

Section 1.5. Quorum. A majority of the outstanding capital stock, represented in person or by proxy, shall constitute a quorum at any meeting of shareholders, unless otherwise provided by law. A majority of the votes cast shall decide every question or matter submitted to the shareholders at any meeting, unless otherwise provided by law or by the Articles of Association.

-1-

ARTICLE II
Directors

Section 2.1. Board of Directors. The board of directors (hereinafter referred to as the "board"), shall have power to manage and administer the business and affairs of the Association. All authorized corporate powers of the Association shall be vested in and may be exercised by the board.

Section 2.2. Powers. In addition to the foregoing, the board of directors shall have and may exercise all of the powers granted to or conferred upon it by the Articles of Association, the Bylaws and by law.

Section 2.3. Number. The board shall consist of a number of members to be fixed and determined from time to time by resolution of the board or the shareholders at any meeting thereof, in accordance with the Articles of Association.

Section 2.4. Organization Meeting. The newly elected board shall meet for the purpose of organizing the new board and electing and appointing such officers of the Association as may be appropriate. Such meeting shall be held on the day of the election or as soon thereafter as practicable, and, in any event, within thirty days thereafter. If, at the time fixed for such meeting, there shall not be a quorum present, the directors present may adjourn the meeting until a quorum is obtained.

Section 2.5. Regular Meetings. The regular meetings of the board shall be held, without notice, as the Chairman or President may designate and deem suitable.

Section 2.6. Special Meetings. Special meetings of the board may be called by the Chairman or the President of the Association, or at the request of two or more directors. Each member of the board shall be given notice stating the time and place of each such meeting.

Section 2.7. Quorum. A majority of the directors shall constitute a quorum at any meeting, except when otherwise provided by law; but fewer may adjourn any meeting. Unless otherwise provided, once a quorum is established, any act by a majority of those constituting the quorum shall be the act of the board.

Section 2.8. Vacancies. When any vacancy occurs among the directors, the remaining members of the board may appoint a director to fill such vacancy at any regular meeting of the board, or at a special meeting called for that purpose.

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ARTICLE III
Committees

Section 3.1. Advisory Board of Directors. The board may appoint persons, who need not be directors, to serve as advisory directors on an advisory board of directors established with respect to the business affairs of either this Association alone or the business affairs of a group of affiliated organizations of which this Association is one. Advisory directors, shall have such powers and duties as may be determined by the board, provided, that the board's responsibility for the business and affairs of this Association shall in no respect be delegated or diminished.

Section 3.2. Audit Committee. The board shall appoint an Audit Committee which shall consist of at least two Directors of the Association or of an affiliate of the Association. If legally permissible, the Board may determine to name itself as the Audit Committee. The Audit Committee shall direct and review audits of the Association's fiduciary activities.

The members of the Audit Committee shall be appointed each year and shall continue to act until their successors are named. The Audit Committee shall have power to adopt its own rules and procedures and to do those things which in the judgment of such Committee are necessary or helpful with respect to the exercise of its functions or the satisfaction of its responsibilities.

Section 3.3. Executive Committee. The board may appoint an Executive Committee which shall consist of at least three directors and which shall have, and may exercise, all the powers of the board between meetings of the board or otherwise when the board is not meeting.

Section 3.4. Other Committees. The board may appoint, from time to time, committees of one or more persons who need not be directors, for such purposes and with such powers as the board may determine. In addition, either the Chairman or the President may appoint, from time to time, committees of one or more officers, employees, agents or other persons, for such purposes and with such powers as either the Chairman or the President deems appropriate and proper.

Whether appointed by the board, the Chairman, or the President, any such Committee shall at all times be subject to the direction and control of the board.

Section 3.5. Meetings. Minutes and Rules. An advisory board of directors and/or committee shall meet as necessary in consideration of the purpose of the advisory board of directors or committee, and shall maintain minutes in sufficient detail to indicate actions taken or recommendations made; unless required by the members, discussions,

-3-

votes or other specific details need not be reported. An advisory board of directors or a committee may, in consideration of its purpose, adopt its own rules for the exercise of any of its functions or authority.

ARTICLE IV
Officers and Employees

Section 4.1. Chairman of the Board. The board may appoint one of its members to be Chairman of the board to serve at the pleasure of the board. The Chairman shall supervise the carrying out of the policies adopted or approved by the board; shall have general executive powers, as well as the specific powers conferred by these Bylaws; shall also have and may exercise such powers and duties as from time to time may be conferred upon or assigned by the board.

Section 4.2. President. The board may appoint one of its members to be President of the Association. In the absence of the Chairman, the President shall preside at any meeting of the board . The President shall have general executive powers, and shall have and may exercise any and all other powers and duties pertaining by law, regulation or practice, to the Office of President, or imposed by these Bylaws. The President shall also have and may exercise such powers and duties as from time to time may be conferred or assigned by the Board.

Section 4.3. Vice President. The board may appoint one or more Vice Presidents who shall have such powers and duties as may be assigned by the board and to perform the duties of the President on those occasions when the President is absent, including presiding at any meeting of the board in the absence of both the Chairman and President.

Section 4.4. Secretary. The board shall appoint a Secretary, or other designated officer who shall be Secretary of the board and of the Association, and shall keep accurate minutes of all meetings. The Secretary shall attend to the giving of all notices required by these Bylaws to be given; shall be custodian of the corporate seal, records, document and papers of the Association; shall provide for the keeping of proper records of all transactions of the Association; shall have and may exercise any and all other powers and duties pertaining by law, regulation or practice, to the Secretary, or imposed by these Bylaws; and shall also perform such other duties as may be assigned from time to time, by the Board.

Section 4.5. Other Officers. The board may appoint, and may authorize the Chairman or the President to appoint, any officer as from time to time may appear to the board, the Chairman or the President to be required or desirable to transact the business of the Association. Such officers shall exercise such powers and perform such duties as pertain to their several offices, or as may be conferred upon or assigned to them by these Bylaws, the board, the Chairman or the President.

-4-

Section 4.6. Tenure of Office. The Chairman or the President and all other officers shall hold office for the current year for which the board was elected, unless they shall resign, become disqualified, or be removed. Any vacancy occurring in the Office of Chairman or President shall be filled promptly by the board.

Any officer elected by the board or appointed by the Chairman or the President may be removed at any time, with or without cause, by the affirmative vote of a majority of the board or, if such officer was appointed by the Chairman or the President, by the Chairman or the President, respectively.

ARTICLE V
Stock

Section 5.1. Shares of stock shall be transferable on the books of the Association, and a transfer book shall be kept in which all transfers of stock shall be recorded. Every person becoming a shareholder by such transfer shall, in proportion to such person's shares, succeed to all rights of the prior holder of such shares. Each certificate of stock shall recite on its face that the stock represented thereby is transferable only upon the books of the Association properly endorsed.

ARTICLE VI
Corporate Seal

Section 6.1. The Chairman, the President, the Secretary, any Assistant Secretary or other officer designated by the board, the Chairman, or the President, shall have authority to affix the corporate seal to any document requiring such seal, and to attest the same. Such seal shall be substantially in the following form:

ARTICLE VII
Miscellaneous Provisions

Section 7.1. Execution of Instruments. All agreements, checks, drafts, orders, indentures, notes, mortgages, deeds, conveyances, transfers, endorsements, assignments, certificates, declarations, receipts, discharges, releases, satisfactions, settlements, petitions, schedules, accounts, affidavits, bonds, undertakings, guarantees, proxies and other instruments or documents may be signed, countersigned, executed, acknowledged, endorsed, verified, delivered or accepted on behalf of the Association, whether in a fiduciary capacity or otherwise, by any officer of the Association, or such employee or agent as may be designated from time to time by the board by resolution, or by the Chairman or the President by written instrument, which resolution or instrument shall be certified as in effect by the Secretary or an Assistant Secretary of the

-5-

Association. The provisions of this section are supplementary to any other provision of the Articles of Association or Bylaws.

Section 7.2. Records. The Articles of Association, the Bylaws and the proceedings of all meetings of the shareholders, the board, and standing committees of the board, shall be recorded in appropriate minute books provided for the purpose. The minutes or each meeting shall be signed by the Secretary, or other officer appointed to act as Secretary of the meeting.

Section 7.3. Trust Files. There shall be maintained in the Association files all fiduciary records necessary to assure that its fiduciary responsibilities have been properly undertaken and discharged.

Section 7.4. Trust Investments. Funds held in a fiduciary capacity shall be invested according to the instrument establishing the fiduciary relationship and according to law. Where such instrument does not specify the character and class of investments to be made and does not vest in the Association a discretion in the matter, funds held pursuant to such instrument shall be invested in investments in which corporate fiduciaries may invest under law.

Section 7.5. Notice. Whenever notice is required by the Articles of Association, the Bylaws or law, such notice shall be by mail, postage prepaid, telegram, in person, or by any other means by which such notice can reasonably be expected to be received, using the address of the person to receive such notice, or such other personal data, as may appear on the records of the Association. Prior notice shall be proper if given not more than 30 days nor less than 10 days prior to the event for which notice is given.

ARTICLE VIII
Indemnification

Section 8.1. The association shall indemnify to the full extent permitted by, and in the manner permissible under, the Articles of Association and the laws of the United States of America, as applicable and as amended from time to time, any person made, or threatened to be made, a party to any action, suit or proceeding, whether criminal, civil, administrative or investigative, by reason of the fact that such person is or was a director, advisory director, officer or employee of the Association, or any predecessor of the Association, or served any other enterprise as a director or officer at the request of the Association or any predecessor of the Association.

Section 8.2. The board in its discretion may, on behalf of the Association, indemnify any person, other than a director, advisory director, officer or employee, made a party to any action, suit or proceeding by reason of the fact that such person is or was an agent of the Association or any predecessor of the Association serving in such capacity at the request of the Association or any predecessor of the Association.

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ARTICLE IX
Bylaws: Interpretation and Amendment

Section 9.1. These Bylaws shall be interpreted in accordance with and subject to appropriate provisions of law, and may be amended, altered or repealed, at any regular or special meeting of the board.

Section 9.2. A copy of the Bylaws, with all amendments, shall at all times be kept in a convenient place at the main office of the Association, and shall be open for inspection to all shareholders during Association hours.

I, Catherine F. Donohue, hereby certify that: (i) I am a duly constituted Assistant Secretary of FIRST TRUST OF NEW YORK, NATIONAL ASSOCIATION (the "Association") and (ii) the foregoing bylaws are the bylaws of the Association, and all of them are now lawfully in force and effect.

I have hereunto affixed my official signature and the seal of the Association, in the City of New York, on the 22nd day of September, 1997.

By: /s/ Catherine F. Donohue
   ---------------------------------
Name:   Catherine F. Donohue
Title:  Assistant  Secretary

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Exhibit 7

FIRST TRUST OF NEW YORK, NATIONAL ASSOCIATION
STATEMENT OF FINANCIAL CONDITION
AS OF 6/30/97

                                    ($000'S)

                                                    6/30/97
                                                   ---------
ASSETS
   Cash and Due From Depository Institutions       $  35,121
   Federal Reserve Stock                               3,490
   Fixed Assets                                          802
   Intangible Assets                                  77,269
   Other Assets                                        5,921
                                                   ---------
      TOTAL ASSETS                                 $ 122,603
                                                   =========


LIABILITIES
   Other Liabilities                                   7,037
                                                   ---------
   TOTAL LIABILITIES                                     703

EQUITY
   Common and Preferred Stock                          1,000
   Surplus                                           120,932
   Undivided Profits                                  (6,367)
                                                   ---------
      TOTAL EQUITY CAPITAL                           115,565

TOTAL LIABILITIES AND EQUITY CAPITAL               $ 122,603
                                                   =========

To the best of the undersigned's determination, as of this date the above financial information is true and correct.

First Trust of New York, National Association

By: /s/ Catherine F. Donohue
    ---------------------------------
    Vice President


Date: September 22, 1997