EXHIBIT 4

                     SCHERING-PLOUGH CORPORATION

                        AMENDMENT TO BY-LAWS


     Effective September 22, 1998, pursuant to a resolution of 
the Board of Directors, the By-laws of Schering-Plough 
Corporation have been amended as follows:

1.   By deleting the second, third and fourth sentences of the 
second paragraph of Section 2 of Article III and replacing such 
sentences with the following:

"For business to be properly brought before an annual meeting by 
a shareholder, the shareholder must have given timely notice 
thereof in writing to the Secretary of the Corporation and such 
business must otherwise be a proper matter for shareholder 
action.  To be timely, a shareholder's notice shall be delivered 
to the Secretary at the principal executive offices of the 
Corporation not later than the close of business on the 90th day 
nor earlier than the close of business on the 120th day prior to 
the first anniversary of the preceding year's annual meeting; 
provided, however, that in the event that the date of the annual 
meeting is more than 30 days before or more than 60 days after 
such anniversary date, notice by the shareholder to be timely 
must be so delivered not earlier than the close of business on 
the 120th day prior to such annual meeting and not later than the 
close of business on the later of the 90th day prior to such 
annual meeting or the 10th day following the day on which public 
announcement of the date of such meeting is first made by the 
Corporation.  In no event shall the public announcement of an 
adjournment of an annual meeting commence a new time period for 
the giving of a shareholder's notice as described above.  Such 
shareholder's notice shall set forth (a) as to any business that 
the shareholder proposes to bring before the meeting, a brief 
description of the business desired to be brought before the 
meeting, the reasons for conducting such business at the meeting 
and any material interest in such business of such shareholder 
and the beneficial owner, if any, on whose behalf the proposal is 
made; and (b) as to the shareholder giving the notice and the 
beneficial owner, if any, on whose behalf the nomination or 
proposal is made (i) the name and address of such shareholder as 
they appear on the Corporation's books, and of such beneficial 
owner and (ii) the class and number of shares of the Corporation 
which are owned beneficially and of record by such shareholder 
and such beneficial owner."

2.    By deleting the phrase "by oral telegraph and written 
notice given to each director not less than forty-eight hours 
before such meeting" from Section 5 of Article V and replacing 
such phrase with the following:

     "Notice of any special meeting of directors shall be given 
to each director at his business or residence in writing by hand 
delivery, first-class or overnight mail or courier service, 
telegram or facsimile transmission, or orally by telephone.  If 
mailed by first-class mail, such notice shall be deemed 
adequately delivered when deposited in the United States mails so 
addressed, with postage thereon prepaid, at least five (5) days 
before such meeting.  If by telegram, overnight mail or courier 
service, such notice shall be deemed adequately delivered when 
the telegram is delivered to the telegraph company or the notice 
is delivered to the overnight mail or courier service company at 
least twenty-four (24) hours before such meeting.  If by 
facsimile transmission, such notice shall be deemed adequately 
delivered when the notice is transmitted at least twelve (12) 
hours before such meeting.  If by telephone or by hand delivery, 
the notice shall be given at least twelve (12) hours prior to the 
time set for the meeting.  A meeting may be held at any time 
without notice if all the directors are present or if those not 
present waive notice of the meeting.  Members of the Board of 
Directors, or any committee thereof, may participate in a meeting 
of the Board of Directors or such committee by means of 
conference telephone or similar communications equipment by means 
of which all persons participating in the meeting can hear each 
other, and such participation in a meeting shall constitute 
presence in person at such meeting.