SECURITIES AND EXCHANGE COMMISSION
                          WASHINGTON, D.C.  20549
                             ________________

                                 FORM  S-8
                       REGISTRATION STATEMENT UNDER
                        THE SECURITIES ACT OF 1933
                             ________________

                        SIGMA-ALDRICH CORPORATION             
          (Exact name of registrant as specified in its charter)
        
           DELAWARE                                             43-1050617    
  (State or other jurisdiction                              (I.R.S. Employer
of incorporation or organization)                          Identification No.)

                            3050 SPRUCE STREET
                            ST. LOUIS, MO  63103         
                 (Address of principal Executive Offices)

            SIGMA-ALDRICH CORPORATION SHARE OPTION PLAN OF 1995
                         (Full title of the plan)

                              KIRK A. RICHTER
                                CONTROLLER
                         SIGMA-ALDRICH CORPORATION
                            3050 SPRUCE STREET
                           ST. LOUIS, MO  63103
                                (314) 771-5765                     
         (Name, address and telephone number of agent for service)



                      CALCULATION OF REGISTRATION FEE



                                   Proposed       Proposed
 Title of                          Maximum        Maximum
 Securities       Amount           Offering       Aggregate       Amount of
 to be            to be            Price          Offering        Registration
 Registered       Registered(1)    Per Share(2)   Price           Fee         
 Common Stock,    2,000,000        $48.00         $96,000,000     $33,104
 par value        shares
 $1.00 per
 share


Notes:

(1)  The registration statement also includes an indeterminable number of
     additional shares that may become issuable pursuant to antidilution
     provisions.

(2)  Estimated solely for the purpose of calculating the registration fee
     pursuant to Rule 457(h) based on the average of the high and low prices
     for the Common Stock on September 5, 1995, as reported by NASDAQ.


                                 PART  II
            INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
                                     
Item 3.   Incorporation of Certain Documents by Reference

          The following documents, which are on file with the Securities and
       Exchange Commission, are incorporated herein by reference:

       (a) Sigma-Aldrich Corporation's (the "Company") Annual Report on Form
           10-K for the year ended December 31, 1994 (File No.
           0-8135); 
       (b) The Company's Quarterly Reports on Form 10-Q for the quarters
           ended March 31, and June 30, 1995 (File No. 0-8135);
       (c) The description of the Company's Common Stock contained in the
           Company's registration statement on Form S-14 under the 1933 Act,
           dated May 16, 1975 (File No. 2-53698), as amended by the
           description contained in the Company's proxy statements dated May
           29, 1984 under the caption "Proposal to amend Certificate of
           Incorporation" and dated March 29, 1991 under the caption
           "Proposal to amend Certificate of Incorporation to Increase
           authorized Common Stock."
           
          All documents subsequently filed by the Registrant pursuant to
       Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of
       1934 (the "1934 Act"), prior to the filing of a post-effective
       amendment which indicates that all securities offered have been sold or
       which deregisters all securities then remaining unsold, shall be deemed
       to be incorporated by reference in this registration statement and to
       be a part hereof from the date of filing of such documents.  Any
       statement contained in a document incorporated or deemed to be
       incorporated herein by reference shall be deemed to be modified or
       superseded for purposes of this registration statement to the extent
       that a statement contained herein or in any other subsequently filed
       document which also is or is deemed to be incorporated by reference
       herein modifies or supersedes such statement.

Item 4.   Description of Securities

          The authorized capital stock of the Company consists of 100,000,000
       shares of Common Stock, $1.00 par value per share.  Dividends may be
       paid on the Common Stock as and when declared by the Board of Directors
       out of any funds legally available therefor.  The holders of Common
       Stock are entitled to one vote per share in the election of directors
       and in respect of other matters submitted to shareholders for a vote. 
       Upon liquidation, the holders of the Common Stock are entitled to
       receive all assets of the Company available for distribution to
       shareholders pro rata in accordance with their holdings.

          The Company's Certificate of Incorporation as amended requires that
       a merger or consolidation of the Company with another corporation or
       which involves a subsidiary of the Company when shares of the Company
       in excess of 35% of the outstanding shares are issued; a sale of assets
       having an aggregate book value of 20% of the Company's total assets;
       the adoption of a plan of liquidation or dissolution; and certain
       related transactions, must be approved by the affirmative vote of two-
       thirds of the shares of voting stock.

          The Common Stock has no preemptive or conversion rights, redemption
       provisions or sinking fund provisions.  The outstanding Common Stock,
       including the Common Stock offered hereby, is fully-paid and
       nonassessable.

          The transfer agent for the Common Stock is the Boatmen's Trust
       Company, St. Louis, Missouri.    

Item 5.   Interests of Named Experts and Counsel

          Jerome W. Sandweiss, a Director of the Registrant, is of counsel with
       the law firm of Blumenfeld, Kaplan & Sandweiss, P.C.  Mr. Sandweiss
       owns, directly and indirectly, an aggregate of Twelve Thousand (12,000)
       shares of the Registrant's Common Stock.  Blumenfeld, Kaplan &
       Sandweiss, P.C. has rendered its opinion concerning the shares of
       Common Stock covered by the Plan as set forth in Exhibit No. 5 to this
       registration statement.

Item 6.   Indemnification of Directors and Officers

          Section 145(a) of the Delaware General Corporation Law provides
       that a corporation may indemnify any director, officer, employee or
       agent of the corporation in any action, other than an action by or in
       the right of the corporation, if such person acted in good faith and in
       a manner he reasonably believed to be in or not opposed to the best
       interests of the corporation and, with respect to any criminal action,
       had no reasonable cause to believe his conduct was unlawful.  Section
       145(b) provides that the corporation may indemnify any such person in
       an action by or in the right of the corporation if he acted in good
       faith and in a manner he reasonably believed to be in or not opposed to
       the best interests of the corporation, except that such person may not
       be indemnified in respect of any matter in which he has been judged
       liable to the corporation, unless authorized by the court.  Section
       145(c) provides that the corporation shall indemnify any such person
       against expenses actually and reasonably incurred in defense of any
       action if he has been successful in defense of such action and if such
       action is one for which the corporation may indemnify such person under
       Section 145(a) or (b).

          The Company's By-Laws provide that it shall indemnify, and in the
       Company's discretion may obtain insurance for the benefit of its
       officers and directors, to the extent permitted by applicable Delaware
       law. The Plan provides that the Company will indemnify each member of
       the Board of Directors and the Compensation Committee (the "Committee")
       for any action or failure to act under the Plan, except in satisfaction
       of a judgment based upon a finding of bad faith.

          Pursuant to amendments of the Delaware General Corporation Law
       effective July 1, 1986, the Company's Certificate of Incorporation
       eliminates the personal liability of directors to the Company or its
       shareholders for monetary damages for breach of fiduciary duty as a
       director, except (i) for breaches of the duty of loyalty to the Company
       or its shareholders, (ii) for acts or omissions not in good faith or
       involving intentional misconduct or knowing violation of law, (iii) for 
       the payment of unlawful dividends or unlawful stock repurchases or
       redemptions, or (iv) for transactions in which the director received an
       improper personal benefit.

Item 7.   Exemption from Registration Claimed

          Not applicable.

Item 8.   Exhibits

          The exhibits to the registration statement are listed in the Exhibit
          Index elsewhere herein.

Item 9.   Undertakings 

 (a) 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.  Notwithstanding the foregoing, any increase or
                decrease in volume of securities offered (if the total
                dollar value of securities offered would not exceed that
                which was registered) and any deviation from the low or high
                end of the estimated maximum offering range may be reflected
                in the form of prospectus filed with the Commission pursuant
                to Rule 424(b) if, in the aggregate, the changes in volume
                and price represent no more than a 20% change in the maximum
                aggregate offering price set forth in the "Calculation of
                Registration Fee" table in the effective 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 (a)(1)(i) and (a)(1)(ii)
                do not apply if the registration statement is on Form S-3 or
                Form S-8, and 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.

  (b)    The undersigned Registrant hereby undertakes 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 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. 
       
  (c)    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 foregoing provisions, 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 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 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.


                                SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized in the City of St. Louis and State of Missouri on the 15th day of
August, 1995.

                                   SIGMA-ALDRICH CORPORATION
                                          (Registrant)


                                   BY:    /s/  Kirk A. Richter       
                                         Kirk A. Richter, Controller

                            POWER  OF  ATTORNEY

          Each person whose signature appears below constitutes and appoints
Peter A. Gleich and Kirk A. Richter, and either of them, his true and lawful
attorneys-in-fact and agents, with full power of substitution and 
resubstitution, for him and in his name, place and stead, in any and all 
capacities, to sign any or all amendments to this registration statement and
to file the same, with all exhibits thereto and all other documents in 
connection therewith with the Securities and Exchange Commission, granting 
unto said attorneys-in-fact and agents full power and authority to do and 
perform each and every act and thing requisite and necessary to be done in 
and about the premises, as fully as he might or could do in person, hereby 
ratifying and confirming all that said attorneys-in-fact and agents 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 on behalf
of the Registrant and in the capacities and on the dates indicated.

          SIGNATURE / TITLE                                DATE

       By  /s/     Carl T. Cori                        August 15, 1995
          Carl T. Cori, Director, Chairman of the           Date
           Board and Chief Executive Officer   
           
       By  /s/     David R. Harvey                     August 15, 1995
          David R. Harvey, Director, President and          Date
           Chief Operating Officer

       By  /s/     Peter A. Gleich                     August 15, 1995
          Peter A. Gleich, Vice President and               Date
           Treasurer

       By  /s/     Thomas M. Tallarico                 August 15, 1995
          Thomas M. Tallarico, Vice President and           Date
           Secretary 

       By  /s/     Kirk A. Richter                     August 15, 1995
          Kirk A. Richter, Controller                       Date


       By  /s/     Andrew E. Newman                    August 15, 1995
          Andrew E. Newman, Director                        Date

       By  /s/     David M. Kipnis                     August 15, 1995
          David M. Kipnis, Director                         Date

       By  /s/     Jerome W. Sandweiss                 August 15, 1995
          Jerome W. Sandweiss, Director                     Date

<PAGE>

                               EXHIBIT INDEX

Exhibit No.                        Description

   4a.     Certificate of Incorporation and Amendments
           (incorporated by reference to Exhibit 3(a)of
           Form 10-K filed for the year ended December 31, 1991,
           File No. 0-8135).

   4b.     By-Laws as amended February 1993 (incorporated
           by reference to Exhibit 3(b) of Form 10-K filed
           for the year ended December 31, 1992, File No.
           0-8135).

   5.      Opinion of counsel.

   10.     Share Option Plan of 1995 (incorporated by reference
           to Appendix A to the definitive Proxy Statement dated 
           March 30, 1995 for the Company's Annual Meeting of Shareholders
           held on May 2, 1995, File No. 0-8135).

   23a.    Consent of counsel (included in Exhibit No. 5).

   23b.    Consent of Independent Public Accountants.

   24.     Power of Attorney (included on signature page).
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 18435}]
{"company-data": {"conformed-name": "SIGMA ALDRICH CORP", "cik": "0000090185", "assigned-sic": "5160", "irs-number": "431050617", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "033-62541", "film-number": "95572902"}, "business-address": {"street1": "3050 SPRUCE ST", "city": "ST LOUIS", "state": "MO", "zip": "63103", "phone": "3147715765"}, "mail-address": {"street1": "3050 SPRUCE STREET", "city": "ST LOUIS", "state": "MO", "zip": "63103"}, "former-company": [{"former-conformed-name": "SIGMA INTERNATIONAL LTD", "date-changed": "19750925"}, {"former-conformed-name": "ALDRICH CHEMICAL CO INC", "date-changed": "19750908"}]}
SECURITIES AND EXCHANGE COMMISSION
                          WASHINGTON, D.C.  20549
                             ________________

                                 FORM  S-8
                       REGISTRATION STATEMENT UNDER
                        THE SECURITIES ACT OF 1933
                             ________________

                        SIGMA-ALDRICH CORPORATION             
          (Exact name of registrant as specified in its charter)
        
           DELAWARE                                             43-1050617    
  (State or other jurisdiction                              (I.R.S. Employer
of incorporation or organization)                          Identification No.)

                            3050 SPRUCE STREET
                            ST. LOUIS, MO  63103         
                 (Address of principal Executive Offices)

            SIGMA-ALDRICH CORPORATION SHARE OPTION PLAN OF 1995
                         (Full title of the plan)

                              KIRK A. RICHTER
                                CONTROLLER
                         SIGMA-ALDRICH CORPORATION
                            3050 SPRUCE STREET
                           ST. LOUIS, MO  63103
                                (314) 771-5765                     
         (Name, address and telephone number of agent for service)

                      CALCULATION OF REGISTRATION FEE

                                   Proposed       Proposed
 Title of                          Maximum        Maximum
 Securities       Amount           Offering       Aggregate       Amount of
 to be            to be            Price          Offering        Registration
 Registered       Registered(1)    Per Share(2)   Price           Fee         
 Common Stock,    2,000,000        $48.00         $96,000,000     $33,104
 par value        shares
 $1.00 per
 share

Notes:

(1)  The registration statement also includes an indeterminable number of
     additional shares that may become issuable pursuant to antidilution
     provisions.

(2)  Estimated solely for the purpose of calculating the registration fee
     pursuant to Rule 457(h) based on the average of the high and low prices
     for the Common Stock on September 5, 1995, as reported by NASDAQ.

                                 PART  II
            INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
                                     
Item 3.   Incorporation of Certain Documents by Reference

          The following documents, which are on file with the Securities and
       Exchange Commission, are incorporated herein by reference:

       (a) Sigma-Aldrich Corporation's (the "Company") Annual Report on Form
           10-K for the year ended December 31, 1994 (File No.
           0-8135); 
       (b) The Company's Quarterly Reports on Form 10-Q for the quarters
           ended March 31, and June 30, 1995 (File No. 0-8135);
       (c) The description of the Company's Common Stock contained in the
           Company's registration statement on Form S-14 under the 1933 Act,
           dated May 16, 1975 (File No. 2-53698), as amended by the
           description contained in the Company's proxy statements dated May
           29, 1984 under the caption "Proposal to amend Certificate of
           Incorporation" and dated March 29, 1991 under the caption
           "Proposal to amend Certificate of Incorporation to Increase
           authorized Common Stock."
           
          All documents subsequently filed by the Registrant pursuant to
       Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of
       1934 (the "1934 Act"), prior to the filing of a post-effective
       amendment which indicates that all securities offered have been sold or
       which deregisters all securities then remaining unsold, shall be deemed
       to be incorporated by reference in this registration statement and to
       be a part hereof from the date of filing of such documents.  Any
       statement contained in a document incorporated or deemed to be
       incorporated herein by reference shall be deemed to be modified or
       superseded for purposes of this registration statement to the extent
       that a statement contained herein or in any other subsequently filed
       document which also is or is deemed to be incorporated by reference
       herein modifies or supersedes such statement.

Item 4.   Description of Securities

          The authorized capital stock of the Company consists of 100,000,000
       shares of Common Stock, $1.00 par value per share.  Dividends may be
       paid on the Common Stock as and when declared by the Board of Directors
       out of any funds legally available therefor.  The holders of Common
       Stock are entitled to one vote per share in the election of directors
       and in respect of other matters submitted to shareholders for a vote. 
       Upon liquidation, the holders of the Common Stock are entitled to
       receive all assets of the Company available for distribution to
       shareholders pro rata in accordance with their holdings.

          The Company's Certificate of Incorporation as amended requires that
       a merger or consolidation of the Company with another corporation or
       which involves a subsidiary of the Company when shares of the Company
       in excess of 35% of the outstanding shares are issued; a sale of assets
       having an aggregate book value of 20% of the Company's total assets;
       the adoption of a plan of liquidation or dissolution; and certain
       related transactions, must be approved by the affirmative vote of two-
       thirds of the shares of voting stock.

          The Common Stock has no preemptive or conversion rights, redemption
       provisions or sinking fund provisions.  The outstanding Common Stock,
       including the Common Stock offered hereby, is fully-paid and
       nonassessable.

          The transfer agent for the Common Stock is the Boatmen's Trust
       Company, St. Louis, Missouri.    

Item 5.   Interests of Named Experts and Counsel

          Jerome W. Sandweiss, a Director of the Registrant, is of counsel with
       the law firm of Blumenfeld, Kaplan & Sandweiss, P.C.  Mr. Sandweiss
       owns, directly and indirectly, an aggregate of Twelve Thousand (12,000)
       shares of the Registrant's Common Stock.  Blumenfeld, Kaplan &
       Sandweiss, P.C. has rendered its opinion concerning the shares of
       Common Stock covered by the Plan as set forth in Exhibit No. 5 to this
       registration statement.

Item 6.   Indemnification of Directors and Officers

          Section 145(a) of the Delaware General Corporation Law provides
       that a corporation may indemnify any director, officer, employee or
       agent of the corporation in any action, other than an action by or in
       the right of the corporation, if such person acted in good faith and in
       a manner he reasonably believed to be in or not opposed to the best
       interests of the corporation and, with respect to any criminal action,
       had no reasonable cause to believe his conduct was unlawful.  Section
       145(b) provides that the corporation may indemnify any such person in
       an action by or in the right of the corporation if he acted in good
       faith and in a manner he reasonably believed to be in or not opposed to
       the best interests of the corporation, except that such person may not
       be indemnified in respect of any matter in which he has been judged
       liable to the corporation, unless authorized by the court.  Section
       145(c) provides that the corporation shall indemnify any such person
       against expenses actually and reasonably incurred in defense of any
       action if he has been successful in defense of such action and if such
       action is one for which the corporation may indemnify such person under
       Section 145(a) or (b).

          The Company's By-Laws provide that it shall indemnify, and in the
       Company's discretion may obtain insurance for the benefit of its
       officers and directors, to the extent permitted by applicable Delaware
       law. The Plan provides that the Company will indemnify each member of
       the Board of Directors and the Compensation Committee (the "Committee")
       for any action or failure to act under the Plan, except in satisfaction
       of a judgment based upon a finding of bad faith.

          Pursuant to amendments of the Delaware General Corporation Law
       effective July 1, 1986, the Company's Certificate of Incorporation
       eliminates the personal liability of directors to the Company or its
       shareholders for monetary damages for breach of fiduciary duty as a
       director, except (i) for breaches of the duty of loyalty to the Company
       or its shareholders, (ii) for acts or omissions not in good faith or
       involving intentional misconduct or knowing violation of law, (iii) for 
       the payment of unlawful dividends or unlawful stock repurchases or
       redemptions, or (iv) for transactions in which the director received an
       improper personal benefit.

Item 7.   Exemption from Registration Claimed

          Not applicable.

Item 8.   Exhibits

          The exhibits to the registration statement are listed in the Exhibit
          Index elsewhere herein.

Item 9.   Undertakings 

 (a) 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.  Notwithstanding the foregoing, any increase or
                decrease in volume of securities offered (if the total
                dollar value of securities offered would not exceed that
                which was registered) and any deviation from the low or high
                end of the estimated maximum offering range may be reflected
                in the form of prospectus filed with the Commission pursuant
                to Rule 424(b) if, in the aggregate, the changes in volume
                and price represent no more than a 20% change in the maximum
                aggregate offering price set forth in the "Calculation of
                Registration Fee" table in the effective 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 (a)(1)(i) and (a)(1)(ii)
                do not apply if the registration statement is on Form S-3 or
                Form S-8, and 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.

  (b)    The undersigned Registrant hereby undertakes 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 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. 
       
  (c)    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 foregoing provisions, 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 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 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.

                                SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized in the City of St. Louis and State of Missouri on the 15th day of
August, 1995.

                                   SIGMA-ALDRICH CORPORATION
                                          (Registrant)

                                   BY:    /s/  Kirk A. Richter       
                                         Kirk A. Richter, Controller

                            POWER  OF  ATTORNEY

          Each person whose signature appears below constitutes and appoints
Peter A. Gleich and Kirk A. Richter, and either of them, his true and lawful
attorneys-in-fact and agents, with full power of substitution and 
resubstitution, for him and in his name, place and stead, in any and all 
capacities, to sign any or all amendments to this registration statement and
to file the same, with all exhibits thereto and all other documents in 
connection therewith with the Securities and Exchange Commission, granting 
unto said attorneys-in-fact and agents full power and authority to do and 
perform each and every act and thing requisite and necessary to be done in 
and about the premises, as fully as he might or could do in person, hereby 
ratifying and confirming all that said attorneys-in-fact and agents 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 on behalf
of the Registrant and in the capacities and on the dates indicated.

          SIGNATURE / TITLE                                DATE

       By  /s/     Carl T. Cori                        August 15, 1995
          Carl T. Cori, Director, Chairman of the           Date
           Board and Chief Executive Officer   
           
       By  /s/     David R. Harvey                     August 15, 1995
          David R. Harvey, Director, President and          Date
           Chief Operating Officer

       By  /s/     Peter A. Gleich                     August 15, 1995
          Peter A. Gleich, Vice President and               Date
           Treasurer

       By  /s/     Thomas M. Tallarico                 August 15, 1995
          Thomas M. Tallarico, Vice President and           Date
           Secretary 

       By  /s/     Kirk A. Richter                     August 15, 1995
          Kirk A. Richter, Controller                       Date

       By  /s/     Andrew E. Newman                    August 15, 1995
          Andrew E. Newman, Director                        Date

       By  /s/     David M. Kipnis                     August 15, 1995
          David M. Kipnis, Director                         Date

       By  /s/     Jerome W. Sandweiss                 August 15, 1995
          Jerome W. Sandweiss, Director                     Date
EXHIBIT INDEX

Exhibit No.                        Description

   4a.     Certificate of Incorporation and Amendments
           (incorporated by reference to Exhibit 3(a)of
           Form 10-K filed for the year ended December 31, 1991,
           File No. 0-8135).

   4b.     By-Laws as amended February 1993 (incorporated
           by reference to Exhibit 3(b) of Form 10-K filed
           for the year ended December 31, 1992, File No.
           0-8135).

   5.      Opinion of counsel.

   10.     Share Option Plan of 1995 (incorporated by reference
           to Appendix A to the definitive Proxy Statement dated 
           March 30, 1995 for the Company's Annual Meeting of Shareholders
           held on May 2, 1995, File No. 0-8135).

   23a.    Consent of counsel (included in Exhibit No. 5).

   23b.    Consent of Independent Public Accountants.

   24.     Power of Attorney (included on signature page).