U.S. SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                     FORM 4

                  STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

    Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934,
       Section 17(a) of the Public Utility Holding Company Act of 1935 or
               Section 30(f) of the Investment Company Act of 1940

[_]  Check box if no longer  subject to Section 16. Form 4 or Form 5 obligations
     may continue. See Instruction 1(b).

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1.   Name and Address of Reporting Person*

        Shields                         John                    J.
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   (Last)                           (First)             (Middle)

        357 Hale Street, P.O. Box 174
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                                    (Street)

        Prides Crossing                 MA              01965
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   (City)                           (State)              (Zip)


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2.   Issuer Name and Ticker or Trading Symbol


        Ionics, Incorporated (ION)
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3.   IRS Identification Number of Reporting Person, if an Entity (Voluntary)



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4.   Statement for Month/Year


        5/02
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5.   If Amendment, Date of Original (Month/Year)


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6.   Relationship of Reporting Person to Issuer
     (Check all applicable)

     [X]  Director                             [_]  10% Owner
     [_]  Officer (give title below)           [_]  Other (specify below)


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7.   Individual or Joint/Group Filing (Check applicable line)

     [X]  Form filed by one Reporting Person
     [_]  Form filed by more than one Reporting Person
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           Table I -- Non-Derivative Securities Acquired, Disposed of,
                             or Beneficially Owned
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                                                                                                                6.
                                                                 4.                              5.             Owner-
                                                                 Securities Acquired (A) or      Amount of      ship
                                                    3.           Disposed of (D)                 Securities     Form:     7.
                                                    Transaction  (Instr. 3, 4 and 5)             Beneficially   Direct    Nature of
                                      2.            Code         ------------------------------- Owned at End   (D) or    Indirect
1.                                    Transaction   (Instr. 8)                   (A)             of Month       Indirect  Beneficial
Title of Security                     Date          ------------     Amount      or     Price    (Instr. 3      (I)       Ownership
(Instr. 3)                            (mm/dd/yy)     Code     V                  (D)             and 4)         (Instr.4) (Instr. 4)
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Common Stock                          05/08/02       A        V      267*         A     $28.13   3,696           D
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*    If the Form is filed by more than one  Reporting  Person,  see  Instruction
     4(b)(v).

Reminder: Report on a separate line for each class of securities beneficially
          owned directly or indirectly.

                            (Print or Type Responses)

                                                            (Over)
(Form 4-07/99)

*Represents shares acquired by reporting person as payment of retainer fee
pursuant to Ionics, Incorporated 1998 Non-Employee Directors' Fee Plan in a
transaction exempt under Rule 16b-3.



FORM 4 (continued)

Table II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned
         (e.g., puts, calls, warrants, options, convertible securities)

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                                                                                                                    10.
                                                                                                          9.        Owner-
                                                                                                          Number    ship
                                                                                                          of        Form
                    2.                                                                                    Deriv-    of
                    Conver-                    5.                              7.                         ative     Deriv-   11.
                    sion                       Number of                       Title and Amount           Secur-    ative    Nature
                    or                         Derivative    6.                of Underlying     8.       ities     Secur-   of
                    Exer-             4.       Securities    Date              Securities        Price    Bene-     ity:     In-
                    cise     3.       Trans-   Acquired (A)  Exercisable and   (Instr. 3 and 4)  of       ficially  Direct   direct
                    Price    Trans-   action   or Disposed   Expiration Date   ----------------  Deriv-   Owned     (D) or   Bene-
1.                  of       action   Code     of(D)         (Month/Day/Year)            Amount  ative    at End    In-      ficial
Title of            Deriv-   Date     (Instr.  (Instr. 3,    ----------------            or      Secur-   of        direct   Owner-
Derivative          ative    (Month/  8)       4 and 5)      Date     Expira-            Number  ity      Month     (I)      ship
Security            Secur-   Day/     ------   ------------  Exer-    tion               of      (Instr.  (Instr.   (Instr.  (Instr.
(Instr. 3)          ity      Year)    Code V    (A)   (D)    cisable  Date     Title     Shares  5)       4)        4)       4)
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Stock Option                                                                   Common
(right to buy)      $28.13   5/8/02   J*   V    2,000        11/8/02  5/8/12** Stock     2,000   *        2,000      D
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Explanation of Responses:

* Grant to reporting person of option to buy 2,000 shares of Common Stock under
the Ionics, Incorporated 1986 Stock Option Plan for Non-Employee Directors in
a transaction exempt under Rule 16b-3.
**Option expires earlier in the event the reporting person ceases being a
director.


        /s/John J. Shields                                      May 8, 2002
---------------------------------------------            -----------------------
      **Signature of Reporting Person                             Date


**     Intentional misstatements or omissions of facts constitute Federal
       Criminal Violations.

See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note:  File three copies of this Form, one of which must be manually signed.
       If space provided is insufficient, see Instruction 6 for procedure.


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