EXHIBIT 24.2

POWER OF ATTORNEY

     Each of the undersigned does hereby appoint Celia A. Colbert and Kenneth C. Frazier, and each of them severally, to be his or her true and lawful attorney or attorneys to execute on behalf of the undersigned (whether on behalf of Merck & Co., Inc., or as an officer or director thereof, or by attesting the seal of the Company, or otherwise) a Registration Statement in connection with the registration under the Securities Act of 1933, as amended, of shares of Common Stock of Merck & Co., Inc. which may be purchased under the Merial 401(k) Savings Plan (the “Plan”) covered by this Registration Statement, including amendments thereto and all other documents in connection therewith.

     IN WITNESS WHEREOF, this instrument has been duly executed as of the 27^th day of July 2004.

	MERCK & CO., INC.
By:	/s/ Raymond V. Gilmartin
	Raymond V. Gilmartin
	Chairman of the Board, President
	& Chief Executive Officer
	(Principal Executive Officer; Director)
	/s/ Judy C. Lewent
	Judy C. Lewent
	Executive Vice President, Chief
	Financial Officer and President,
	Human Health Asia
	(Principal Financial Officer)
	/s/ Richard C. Henriques, Jr.
	Richard C. Henriques, Jr.
	Vice President, Controller
	(Principal Accounting Officer)

DIRECTORS

/s/ Lawrence A. Bossidy	/s/ Thomas E. Shenk
Lawrence A. Bossidy	Thomas E. Shenk
/s/ William G. Bowen
William G. Bowen	Anne M. Tatlock
/s/ Johnnetta B. Cole	/s/ Samuel O. Thier
Johnnetta B. Cole	Samuel O. Thier
/s/ William B. Harrison, Jr.
William B. Harrison, Jr.	Wendell P. Weeks
/s/ William N. Kelley	/s/ Peter C. Wendell
William N. Kelley	Peter C. Wendell

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