<PAGE>

       As filed with the Securities and Exchange Commission on
       May 3, 1995                            Registration No. 33-
                                                                      




                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549
                         ____________________________
                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                         ____________________________

                             IONICS, INCORPORATED
            (Exact name of registrant as specified in its charter)

          Massachusetts                                  04-2068530
       (State or other jurisdic-                      (I.R.S. Employer
       tion of incorporation                         Identification No.)
       or organization)

                                65 Grove Street
                        Watertown, Massachusetts  02172
             (Address of Principal Executive Offices)  (Zip Code)
                         _____________________________

                             IONICS, INCORPORATED
                          1994 RESTRICTED STOCK PLAN
                           (Full title of the plan)
                         _____________________________

                                 Stephen Korn
                      Vice President and General Counsel
                             Ionics, Incorporated
                                65 Grove Street
                        Watertown, Massachusetts  02172
                                (617) 926-2500
                (Name, address and telephone number, including
                       area code, of agent for service)








       /1

       <PAGE>

       <TABLE>





                         CALCULATION OF REGISTRATION FEE
       ___________________________________________________________________
       <CAPTION>
                                   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(2)         fee(3)
       ___________________________________________________________________
       <S>            <C>           <C>         <C>            <C>
       Common Stock,  450,000 shs.  $27.25      $12,262,500    $4,228.45
       $1.00 par value
       ___________________________________________________________________
       <FN>
       (1)   This Registration Statement also covers such indeterminable
             number of additional shares of Common Stock as may become
             deliverable as a result of future adjustments in accordance
             with the terms of the Ionics, Incorporated 1994 Restricted
             Stock Plan.

       (2)   Estimated solely for the purpose of determining the
             registration fee pursuant to Rule 457(c) and (h) and based
             upon the average of the high and low prices of the Common
             Stock of Ionics, Incorporated (the "Company) on April 27,
             1995, on the New York Stock Exchange.

       (3)   Pursuant to Section 6(b).
       </TABLE>
             This Registration Statement will become effective
       automatically upon the date of filing, pursuant to the provisions
       of Section 8 of the Securities Act of 1933 and Rule 462 enacted
       thereunder, or such other day as the Commission acting pursuant to
       said Section 8 may determine.
       __________________________________________________________________

             The approximate date of proposed sale to the public and cross
       reference sheet called for by Items 501(a) and (b) of Regulation 
       S-K are not applicable and have been omitted.








                                       -2-

       /2

       <PAGE>





                                     PART I

             Pursuant to Part I of Form S-8, the information required by
       Item 1, Plan Information, and Item 2, Registrant Information and
       Employee Plan Annual Information, of Form S-8 has not been filed as
       part of this Registration Statement.

                                     PART II

       Item 3.  Incorporation of Documents by Reference.

             The following documents filed with the Securities and
       Exchange Commission are hereby incorporated by reference:

             (a)  The Annual Report of the Company on Form 10-K for the
       fiscal year ended December 31, 1994.

             (b)  The description of the Company's Common Stock contained
       in the Company's Registration Statement on Form 8-A filed under the
       Securities Exchange Act of 1934 pursuant to Section 12 thereof.

             All documents subsequently filed by the Company pursuant to
       Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
       of 1934 prior to the filing of a post-effective amendment which
       indicates that all securities offered hereby have been sold or
       which deregisters all securities then remaining unsold, shall be
       deemed to be incorporated by reference herein 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 by reference herein 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.  Any such statement so modified or superseded shall not
       be deemed, except as so modified or superseded, to constitute part
       of this Registration Statement.









                                       -3-

       /3

       <PAGE>







       Item 4.  Description of Securities.

             Not applicable.

       Item 5.  Interests of Named Experts and Counsel.

             Certain legal matters in connection with the offering of the
       shares of Common Stock of the Company are being passed upon for the
       Company by Stephen Korn, Vice President, General Counsel and Clerk
       of the Company.  Mr. Korn is the beneficial owner of 42,800 shares
       of Common Stock in the form of presently exercisable stock options,
       and 94 shares held in the Company's Section 401(k) Stock Savings
       Plan (based on December 31, 1994 401(k) plan data).

       Item 6.  Indemnification of Directors and Officers.

             The Company is permitted by Massachusetts law and required by
       its By-laws to indemnify any director or officer or former director
       or officer against all expenses and liabilities reasonably incurred
       by him in connection with any legal action in which such person is
       involved by reason of his position with the Company unless he shall
       have been finally adjudicated in any action, suit or proceeding not
       to have acted in good faith in the reasonable belief that his
       action was in the best interests of the Company.  Such
       indemnification shall include payment by the Company of expenses
       incurred in defending a civil or criminal action or proceeding in
       advance of the final disposition of such action, or defending a
       civil or criminal action or proceeding, upon the Company's receipt
       of the undertaking of the person indemnified to repay such payment
       if such person shall be adjudicated not entitled to such
       indemnification.

             Directors and officers are also insured up to an aggregate
       amount of $5,000,000 under a Directors' and Officers' Liability and
       Company Reimbursement Policy.

             The Company's Restated Articles of Organization include a
       provision limiting the personal liability of a director of the
       Company to its stockholders for monetary damages for breaches of
       their fiduciary duty to the extent permitted by the Massachusetts
       Business Corporation Law.







                                       -4-

       /4

       <PAGE>

             See Item 9(c) for a statement concerning indemnification for
       liabilities under the Securities Act of 1933.

       Item 7.  Exemption for Registration Claimed.

             Not applicable.

       Item 8.  Exhibits.

             Exhibit No.      Description

               4.0         Instruments defining the rights of security
                           holders, including indentures

                    *4.1      Rights Agreement, dated as of December 22,
                              1987, as amended and restated as of August
                              22, 1989, between the Company and The First
                              National Bank of Boston (filed as Exhibit 1
                              to the Company's Current Report on Form 8-K
                              dated August 30, 1989).

                    *4.2      Indenture, dated as of December 22, 1987,
                              between the company and The First National
                              Bank of Boston, relating to Rights Agreement
                              (filed as Exhibit 2 to the Company's Current
                              Report on Form 8-K dated December 22, 1987).

                    *4.3      Form of Common Stock Certificate (filed as
                              Exhibit 4.10 to the Company's registration
                              statement on Form S-2, No. 33-38290, filed
                              on December 18, 1990).

                    *4.4      Ionics, Incorporated 1979 Stock Option Plan,
                              as amended through February 17, 1994 (filed
                              as Exhibit 10.1 to the Company's Annual
                              Report on Form 10-K for the year ended
                              December 31, 1993).

                    *4.5      Ionics, Incorporated 1994 Restricted Stock
                              Plan (filed as Exhibit 10.12 to the
                              Company's Annual Report on Form 10-K for the
                              year ended December 31, 1994).

               5.0         Opinion re legality

                     5.1      Opinion of Stephen Korn, General Counsel

              24.0         Consents of experts and counsel

       __________________
       *Incorporated herein by reference



                                       -5-

       /5

       <PAGE>
             Exhibit No.      Description

                     24.1     Consent of Coopers & Lybrand L.L.P.

                     24.2     Consent of Stephen Korn, General Counsel
                              (contained in Exhibit 5 hereto)

              25.0         Power of attorney 

       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, represents 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 (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.




                                       -6-

       /6

       <PAGE>

             (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 connected 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 Town of
       Watertown and Commonwealth of Massachusetts on the 3rd day of May,
       1995.

                                  IONICS, INCORPORATED


                                  By: /s/ Arthur L. Goldstein               
                                  Arthur L. Goldstein, Chairman of the Board,
                                  President and Chief Executive Officer     





                                       -7-
       /7

       <PAGE>



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

             Signature                       Title                 Date



       /s/Arthur L. Goldstein          Chairman of the Board,   May 3, 1995 
       Arthur L. Goldstein             President and Chief
                                       Executive Officer
                                       (Principal Executive Officer)


       /s/Robert J. Halliday           Vice President,          May 3, 1995 
       Robert J. Halliday              Finance and Accounting
                                       and Chief Financial Officer
                                       (Principal Financial
                                       and Accounting Officer)
































                                         -8-
       /8

       <PAGE>


             Signature                       Title                 Date



       /s/Arthur L. Goldstein          Director, Chairman of    May 3, 1995 
       Arthur L. Goldstein             the Board of Directors


       /s/William L. Brown             Director                 May 3, 1995 
       William L. Brown


       /s/Arnaud de Vitry d'Avaucourt  Director                 May 3, 1995 
       Arnaud de Vitry d'Avaucourt


       /s/Lawrence E. Fouraker         Director                 May 3, 1995 
       Lawrence E. Fouraker


       /s/Samuel A. Goldblith          Director                 May 3, 1995 
       Samuel A. Goldblith

       /s/Kachig Kachadurian           Director                 May 3, 1995 
       Kachig Kachadurian


       /s/William E. Katz              Director                 May 3, 1995 
       William E. Katz


                                       Director                  
       Robert B. Luick


       /s/John J. Shields              Director                 May 3, 1995 
       John J. Shields


       /s/Carl S. Sloane               Director                 May 3, 1995 
       Carl S. Sloane


       /s/Mark S. Wrighton             Director                 May 3, 1995 
       Mark S. Wrighton

       /s/Allen S. Wyett               Director                 May 3, 1995 
       Allen S. Wyett


                                         -9-
       /9

       <PAGE>
                                      FORM S-8

               IONICS, INCORPORATED 1994 RESTRICTED STOCK OPTION PLAN

                                    EXHIBIT INDEX

       Exhibit No.             Description                    
           4.0            Instruments defining the rights of security
                          holders, including indentures.

                    *4.1      Rights, Agreement, dated as of December 22,
                              1987, as amended and restated as of August 22,
                              1989, between the Company and The First
                              National Bank of Boston (filed as Exhibit 1 to
                              the Company's Current Report on Form 8-K dated
                              August 30, 1989).

                    *4.2      Indenture, dated as of December 22, 1987,
                              between the Company and The First National Bank
                              of Boston, relating to Rights Agreement (filed
                              as Exhibit 2 to the Company's Current Report on
                              Form 8-K dated December 22, 1987).

                    *4.3      Form of Common Stock Certificate (filed as
                              Exhibit 4.10 to the Company's registration
                              statement on Form S-2, No. 33-38290, filed on
                              December 18, 1990).

                    *4.4      Ionics, Incorporated 1979 Stock Option Plan, as
                              amended through February 17, 1994 (filed as
                              Exhibit 10.1 to the Company's Annual Report on
                              Form 10-K for the year ended December 31,
                              1993).

                    *4.5      Ionics, Incorporated 1994 Restricted Stock Plan
                              (filed as Exhibit 10.12 to the Company's Annual
                              Report on Form 10-K for the year ended December
                              31, 1994).

           5.0            Opinion re legality

                     5.1      Opinion of Stephen Korn, Esquire

          24.0            Consents of experts and counsel

                    24.1      Consent of Coopers & Lybrand L.L.P.

                    24.2      Consent of Stephen Korn, 
                              General Counsel 
                              (contained in Exhibit 5 hereto)

          25.0                Power of attorney 

       __________________
       *Incorporated herein by reference

                                       -10-
       /10
<PAGE>
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 21191}]
{"company-data": {"conformed-name": "IONICS INC", "cik": "0000052466", "assigned-sic": "3559", "irs-number": "042068530", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "033-59051", "film-number": "95534160"}, "business-address": {"street1": "65 GROVE ST", "city": "WATERTOWN", "state": "MA", "zip": "02172", "phone": "6179262500"}}
As filed with the Securities and Exchange Commission on
       May 3, 1995                            Registration No. 33-
                                                                      

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549
                         ____________________________
                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                         ____________________________

                             IONICS, INCORPORATED
            (Exact name of registrant as specified in its charter)

          Massachusetts                                  04-2068530
       (State or other jurisdic-                      (I.R.S. Employer
       tion of incorporation                         Identification No.)
       or organization)

                                65 Grove Street
                        Watertown, Massachusetts  02172
             (Address of Principal Executive Offices)  (Zip Code)
                         _____________________________

                             IONICS, INCORPORATED
                          1994 RESTRICTED STOCK PLAN
                           (Full title of the plan)
                         _____________________________

                                 Stephen Korn
                      Vice President and General Counsel
                             Ionics, Incorporated
                                65 Grove Street
                        Watertown, Massachusetts  02172
                                (617) 926-2500
                (Name, address and telephone number, including
                       area code, of agent for service)

       /1
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(2)         fee(3)
       ___________________________________________________________________
Common Stock,  450,000 shs.  $27.25      $12,262,500    $4,228.45
       $1.00 par value
       ___________________________________________________________________
(1)   This Registration Statement also covers such indeterminable
             number of additional shares of Common Stock as may become
             deliverable as a result of future adjustments in accordance
             with the terms of the Ionics, Incorporated 1994 Restricted
             Stock Plan.

       (2)   Estimated solely for the purpose of determining the
             registration fee pursuant to Rule 457(c) and (h) and based
             upon the average of the high and low prices of the Common
             Stock of Ionics, Incorporated (the "Company) on April 27,
             1995, on the New York Stock Exchange.

       (3)   Pursuant to Section 6(b).
This Registration Statement will become effective
       automatically upon the date of filing, pursuant to the provisions
       of Section 8 of the Securities Act of 1933 and Rule 462 enacted
       thereunder, or such other day as the Commission acting pursuant to
       said Section 8 may determine.
       __________________________________________________________________

             The approximate date of proposed sale to the public and cross
       reference sheet called for by Items 501(a) and (b) of Regulation 
       S-K are not applicable and have been omitted.

                                       -2-

       /2
PART I

             Pursuant to Part I of Form S-8, the information required by
       Item 1, Plan Information, and Item 2, Registrant Information and
       Employee Plan Annual Information, of Form S-8 has not been filed as
       part of this Registration Statement.

                                     PART II

       Item 3.  Incorporation of Documents by Reference.

             The following documents filed with the Securities and
       Exchange Commission are hereby incorporated by reference:

             (a)  The Annual Report of the Company on Form 10-K for the
       fiscal year ended December 31, 1994.

             (b)  The description of the Company's Common Stock contained
       in the Company's Registration Statement on Form 8-A filed under the
       Securities Exchange Act of 1934 pursuant to Section 12 thereof.

             All documents subsequently filed by the Company pursuant to
       Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
       of 1934 prior to the filing of a post-effective amendment which
       indicates that all securities offered hereby have been sold or
       which deregisters all securities then remaining unsold, shall be
       deemed to be incorporated by reference herein 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 by reference herein 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.  Any such statement so modified or superseded shall not
       be deemed, except as so modified or superseded, to constitute part
       of this Registration Statement.

                                       -3-

       /3
Item 4.  Description of Securities.

             Not applicable.

       Item 5.  Interests of Named Experts and Counsel.

             Certain legal matters in connection with the offering of the
       shares of Common Stock of the Company are being passed upon for the
       Company by Stephen Korn, Vice President, General Counsel and Clerk
       of the Company.  Mr. Korn is the beneficial owner of 42,800 shares
       of Common Stock in the form of presently exercisable stock options,
       and 94 shares held in the Company's Section 401(k) Stock Savings
       Plan (based on December 31, 1994 401(k) plan data).

       Item 6.  Indemnification of Directors and Officers.

             The Company is permitted by Massachusetts law and required by
       its By-laws to indemnify any director or officer or former director
       or officer against all expenses and liabilities reasonably incurred
       by him in connection with any legal action in which such person is
       involved by reason of his position with the Company unless he shall
       have been finally adjudicated in any action, suit or proceeding not
       to have acted in good faith in the reasonable belief that his
       action was in the best interests of the Company.  Such
       indemnification shall include payment by the Company of expenses
       incurred in defending a civil or criminal action or proceeding in
       advance of the final disposition of such action, or defending a
       civil or criminal action or proceeding, upon the Company's receipt
       of the undertaking of the person indemnified to repay such payment
       if such person shall be adjudicated not entitled to such
       indemnification.

             Directors and officers are also insured up to an aggregate
       amount of $5,000,000 under a Directors' and Officers' Liability and
       Company Reimbursement Policy.

             The Company's Restated Articles of Organization include a
       provision limiting the personal liability of a director of the
       Company to its stockholders for monetary damages for breaches of
       their fiduciary duty to the extent permitted by the Massachusetts
       Business Corporation Law.

                                       -4-

       /4
See Item 9(c) for a statement concerning indemnification for
       liabilities under the Securities Act of 1933.

       Item 7.  Exemption for Registration Claimed.

             Not applicable.

       Item 8.  Exhibits.

             Exhibit No.      Description

               4.0         Instruments defining the rights of security
                           holders, including indentures

                    *4.1      Rights Agreement, dated as of December 22,
                              1987, as amended and restated as of August
                              22, 1989, between the Company and The First
                              National Bank of Boston (filed as Exhibit 1
                              to the Company's Current Report on Form 8-K
                              dated August 30, 1989).

                    *4.2      Indenture, dated as of December 22, 1987,
                              between the company and The First National
                              Bank of Boston, relating to Rights Agreement
                              (filed as Exhibit 2 to the Company's Current
                              Report on Form 8-K dated December 22, 1987).

                    *4.3      Form of Common Stock Certificate (filed as
                              Exhibit 4.10 to the Company's registration
                              statement on Form S-2, No. 33-38290, filed
                              on December 18, 1990).

                    *4.4      Ionics, Incorporated 1979 Stock Option Plan,
                              as amended through February 17, 1994 (filed
                              as Exhibit 10.1 to the Company's Annual
                              Report on Form 10-K for the year ended
                              December 31, 1993).

                    *4.5      Ionics, Incorporated 1994 Restricted Stock
                              Plan (filed as Exhibit 10.12 to the
                              Company's Annual Report on Form 10-K for the
                              year ended December 31, 1994).

               5.0         Opinion re legality

                     5.1      Opinion of Stephen Korn, General Counsel

              24.0         Consents of experts and counsel

       __________________
       *Incorporated herein by reference

                                       -5-

       /5
Exhibit No.      Description

                     24.1     Consent of Coopers & Lybrand L.L.P.

                     24.2     Consent of Stephen Korn, General Counsel
                              (contained in Exhibit 5 hereto)

              25.0         Power of attorney 

       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, represents 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 (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.

                                       -6-

       /6
(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 connected 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 Town of
       Watertown and Commonwealth of Massachusetts on the 3rd day of May,
       1995.

                                  IONICS, INCORPORATED

                                  By: /s/ Arthur L. Goldstein               
                                  Arthur L. Goldstein, Chairman of the Board,
                                  President and Chief Executive Officer     

                                       -7-
       /7
Pursuant to the requirements of the Securities Act of 1933,
       this Registration Statement has been signed by the following
       persons in the capacities and on the dates indicated.

             Signature                       Title                 Date

       /s/Arthur L. Goldstein          Chairman of the Board,   May 3, 1995 
       Arthur L. Goldstein             President and Chief
                                       Executive Officer
                                       (Principal Executive Officer)

       /s/Robert J. Halliday           Vice President,          May 3, 1995 
       Robert J. Halliday              Finance and Accounting
                                       and Chief Financial Officer
                                       (Principal Financial
                                       and Accounting Officer)

                                         -8-
       /8
Signature                       Title                 Date

       /s/Arthur L. Goldstein          Director, Chairman of    May 3, 1995 
       Arthur L. Goldstein             the Board of Directors

       /s/William L. Brown             Director                 May 3, 1995 
       William L. Brown

       /s/Arnaud de Vitry d'Avaucourt  Director                 May 3, 1995 
       Arnaud de Vitry d'Avaucourt

       /s/Lawrence E. Fouraker         Director                 May 3, 1995 
       Lawrence E. Fouraker

       /s/Samuel A. Goldblith          Director                 May 3, 1995 
       Samuel A. Goldblith

       /s/Kachig Kachadurian           Director                 May 3, 1995 
       Kachig Kachadurian

       /s/William E. Katz              Director                 May 3, 1995 
       William E. Katz

                                       Director                  
       Robert B. Luick

       /s/John J. Shields              Director                 May 3, 1995 
       John J. Shields

       /s/Carl S. Sloane               Director                 May 3, 1995 
       Carl S. Sloane

       /s/Mark S. Wrighton             Director                 May 3, 1995 
       Mark S. Wrighton

       /s/Allen S. Wyett               Director                 May 3, 1995 
       Allen S. Wyett

                                         -9-
       /9
FORM S-8

               IONICS, INCORPORATED 1994 RESTRICTED STOCK OPTION PLAN

                                    EXHIBIT INDEX

       Exhibit No.             Description                    
           4.0            Instruments defining the rights of security
                          holders, including indentures.

                    *4.1      Rights, Agreement, dated as of December 22,
                              1987, as amended and restated as of August 22,
                              1989, between the Company and The First
                              National Bank of Boston (filed as Exhibit 1 to
                              the Company's Current Report on Form 8-K dated
                              August 30, 1989).

                    *4.2      Indenture, dated as of December 22, 1987,
                              between the Company and The First National Bank
                              of Boston, relating to Rights Agreement (filed
                              as Exhibit 2 to the Company's Current Report on
                              Form 8-K dated December 22, 1987).

                    *4.3      Form of Common Stock Certificate (filed as
                              Exhibit 4.10 to the Company's registration
                              statement on Form S-2, No. 33-38290, filed on
                              December 18, 1990).

                    *4.4      Ionics, Incorporated 1979 Stock Option Plan, as
                              amended through February 17, 1994 (filed as
                              Exhibit 10.1 to the Company's Annual Report on
                              Form 10-K for the year ended December 31,
                              1993).

                    *4.5      Ionics, Incorporated 1994 Restricted Stock Plan
                              (filed as Exhibit 10.12 to the Company's Annual
                              Report on Form 10-K for the year ended December
                              31, 1994).

           5.0            Opinion re legality

                     5.1      Opinion of Stephen Korn, Esquire

          24.0            Consents of experts and counsel

                    24.1      Consent of Coopers & Lybrand L.L.P.

                    24.2      Consent of Stephen Korn, 
                              General Counsel 
                              (contained in Exhibit 5 hereto)

          25.0                Power of attorney 

       __________________
       *Incorporated herein by reference

                                       -10-
       /10