EXHIBIT 4.1
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                 AMENDMENT NO. 2 TO THE RENEWED RIGHTS AGREEMENT

         AMENDMENT NO. 2, dated as of November 24, 2004 (this "Amendment"), to
the RENEWED RIGHTS AGREEMENT, dated as of August 19, 1997, as amended to date
between IONICS, INCORPORATED, a Massachusetts corporation (the "Company"), and
EQUISERVE TRUST COMPANY, N.A. (as successor to BankBoston, N.A.), as Rights
Agent (the "Rights Agreement"). All terms not otherwise defined herein shall
have the meanings given such terms in the Rights Agreement. Unless otherwise
specified herein, all section references made herein are references to sections
in the Rights Agreement.

                              W I T N E S S E T H:

         WHEREAS, on December 22, 1987, the Board of Directors of the Company
(the "Board") adopted a stockholder rights plan (the "Existing Rights Plan") and
executed a Rights Agreement between the Company and the Rights Agent (the "1987
Agreement");

         WHEREAS, the Existing Rights Plan expired on December 31, 1997;

         WHEREAS, on August 19, 1997 the Board determined it desirable and in
the best interests of the Company and its stockholders for the Company to renew
the Existing Rights Plan upon its expiration and to implement such renewal by
executing the Rights Agreement;

         WHEREAS, on November 2, 2003, the Board authorized and approved
Amendment No. 1 to the Rights Agreement, which was entered into on November 17,
2003;

         WHEREAS, pursuant to Section 26 of the Rights Agreement, the Company
may cause the Rights Agreement to be amended at any time prior to the
Distribution Date without the approval of any holders of certificates
representing shares of Common Stock of the Company;

         WHEREAS, as of the date of this Amendment, the Distribution Date has
not occurred;

         WHEREAS, on November 23, 2004, the Board authorized and approved the
acquisition (the "2004 Acquisition") of the Company by General Electric Company
as provided under that certain Agreement and Plan of Merger (the "Merger
Agreement") dated as of November 24, 2004 by and among the Company, General
Electric Company and Triton Acquisition Corp., a Massachusetts corporation and a
wholly-owned subsidiary of General Electric Company;

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         WHEREAS, on November 23, 2004, the Board authorized and approved those
certain Voting Agreements dated as of November 24, 2004 by and among General
Electric Company and the stockholders of the Company party thereto relating to
the 2004 Acquisition and the Merger Agreement (collectively, the "Voting
Agreement"); and

         WHEREAS, in anticipation of and in connection with the execution and
delivery of the Voting Agreement and the 2004 Acquisition, on November 23, 2004,
the Board authorized and approved an amendment of the Rights Agreement for the
express purpose of rendering the Rights Agreement inapplicable to the execution
and delivery of the Voting Agreement and the 2004 Acquisition, including without
limitation, the acquisition of the Company's Common Stock by General Electric
Company or its Subsidiaries, Affiliates or Associates and the other transactions
contemplated by the Merger Agreement;

         NOW, THEREFORE, in consideration of these premises and for other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereby agree as follows:

         1. Notwithstanding anything to the contrary in the Rights Agreement,
the Rights Agreement shall not apply to, and neither General Electric Company
nor its Subsidiaries, Affiliates or Associates will become an Acquiring Person
upon, and no Distribution Date, Section 11(a)(ii) Event, Stock Acquisition Date
or Triggering Event will occur as a result of, (i) the approval, execution,
delivery, consummation or performance of the Merger Agreement or the Voting
Agreement, (ii) the announcement of the 2004 Acquisition, or (iii) the
consummation of the 2004 Acquisition.

         2. The definition of "Acquiring Person" set forth in Section 1(a) is
hereby amended and restated in its entirety as follows:

                  "Acquiring Person" shall mean any Person (as hereinafter
                  defined) who or which, together with all Affiliates and
                  Associates (each as hereinafter defined) of such Person, shall
                  be the Beneficial Owner (as hereinafter defined) of 15% or
                  more of the shares of Common Stock of the Company then
                  outstanding, but shall not include an Exempt Person, the 2003
                  Special Exempt Persons or the 2004 Special Exempt Persons
                  (each as hereinafter defined).

         3. A new definition is hereby added to Section 1 as Section 1(xx),
which such new definition shall read in its entirety as follows:

                  "2004 Merger Agreement" shall mean that certain Agreement and
                  Plan of Merger dated as of November 24, 2004 by and among the
                  Company, General Electric Company and Triton Acquisition
                  Corp., a Massachusetts corporation and a wholly-owned
                  subsidiary of General Electric Company

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                  (the "2004 Merger Sub"), as amended and supplemented from time
                  to time in accordance with its terms.

         4. A new definition is hereby added to Section 1 as Section 1(yy),
which such new definition shall read in its entirety as follows:

                  "2004 Special Exempt Persons" shall mean, collectively, (i)
                  General Electric Company, (ii) 2004 Merger Sub, (iii) any
                  Subsidiaries, Affiliates or Associates of General Electric
                  Company or 2004 Merger Sub, (iv) any Persons party to the
                  Voting Agreement and (v) any Persons to whom shares of Common
                  Stock of the Company are attributed due to their relationship
                  with any Person described in the immediately preceding clauses
                  (i), (ii), (iii) and (iv) (but only to the extent of such
                  attribution); provided, however, that each such Person shall
                  cease to be 2004 Special Exempt Persons upon the earliest to
                  occur, subsequent to the execution and delivery of the 2004
                  Merger Agreement, of the following events: (A) all Persons
                  described in the immediately preceding clauses (i), (ii),
                  (iii) and (iv), together with their Subsidiaries, Affiliates
                  and Associates, cease to Beneficially Own in the aggregate 15%
                  or more of the shares of Common Stock of the Company then
                  outstanding, or (B) the 2004 Merger Agreement is terminated
                  prior to the consummation of the transactions contemplated
                  thereby.

         5. A new definition is hereby added to Section 1 as Section 1(zz),
which such new definition shall read in its entirety as follows:

                  "Voting Agreement" shall mean those certain Voting Agreements
                  dated as of November 24, 2004 by and among the Company,
                  General Electric Company and the stockholders of the Company
                  party thereto relating to the 2004 Acquisition and the Merger
                  Agreement

         6. The definition of "Final Expiration Date" set forth in Section 1(t)
is hereby amended and restated in its entirety as follows:

                  "Final Expiration Date" shall mean the earlier to occur of (i)
                  the Close of Business on August 19, 2007 and (ii) unless the
                  2004 Merger Agreement is terminated prior to the consummation
                  of the merger contemplated thereby, the Close of Business on
                  the business day immediately preceding the consummation of the
                  2004 Acquisition.

         7. Section 3(a) is hereby amended and restated in its entirety as
follows:

                  (a) Until the earliest of (i) the Close of Business on the
                  tenth Business Day (or such specified or unspecified later
                  date as may be determined by

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                  the Board before the occurrence of a Distribution Date) after
                  the Stock Acquisition Date (or, if the tenth Business Day (or
                  such later date) after the Stock Acquisition Date occurs
                  before the Record Date, the Close of Business on the Record
                  Date), (ii) the Close of Business on the tenth Business Day
                  (or such specified or unspecified later date as may be
                  determined by the Board before the occurrence of a
                  Distribution Date) after the date that a tender or exchange
                  offer by any Person (other than an Exempt Person or, solely
                  with respect to the acquisition of shares of Common Stock of
                  the Company pursuant to the 2003 Ecolochem Purchase Agreement,
                  the 2003 Special Exempt Persons, or solely with respect to the
                  acquisition of shares of Common Stock of the Company pursuant
                  to the 2004 Merger Agreement, the 2004 Special Exempt Persons)
                  is first published or sent or given within the meaning of Rule
                  14d-2(a) of the General Rules and Regulations under the
                  Exchange Act if upon consummation thereof such Person would be
                  the Beneficial Owner of 15% or more of the Common Stock of the
                  Company then outstanding (the earlier of (i) and (ii) being
                  herein referred to as the "Distribution Date"), (x) the Rights
                  will be evidenced (subject to the provisions of paragraphs (b)
                  and (c) of this Section 3) by the certificates for the Common
                  Stock of the Company registered in the names of the holders
                  thereof (which certificates shall be deemed also to be
                  certificates for Rights) and not by separate certificates and
                  (y) the Rights will be transferable only in connection with
                  the transfer of the underlying shares of Common Stock of the
                  Company (including a transfer to the Company). As soon as
                  practicable after the Distribution Date, the Rights Agent will
                  send by first-class, insured, postage prepaid mail, to each
                  record holder of the Common Stock of the Company as of the
                  Close of Business on the Distribution Date, at the address of
                  such holder shown on the records of the Company, one or more
                  rights certificates, substantially in the form attached hereto
                  as Exhibit A (the "Rights Certificates"), evidencing one Right
                  for each share of Common Stock of the Company so held, subject
                  to adjustment as provided herein. In the event that an
                  adjustment in the number of Rights per share of Common Stock
                  of the Company has been made pursuant to Section 11(i) hereof,
                  at the time of distribution of the Rights Certificates, the
                  Company shall not be required to issue Rights Certificates
                  evidencing fractional Rights, but may, in lieu thereof, make
                  the necessary and appropriate rounding adjustments (in
                  accordance with Section 14(a) hereof) so that Rights
                  Certificates representing only whole numbers of Rights are
                  distributed and cash is paid in lieu of any fractional Rights.
                  As of and after the Distribution Date, the Rights will be
                  evidenced solely by such Rights Certificates.

         8. Section 11(a)(ii) is hereby amended and restated in its entirety as
follows:

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            (ii)  In the event (a "Section 11(a)(ii) Event") that any Person
                  (other than an Exempt Person), alone or together with its
                  Affiliates and Associates, shall, at any time after the Rights
                  Dividend Declaration Date, become the Beneficial Owner of 15%
                  or more of the shares of Common Stock of the Company then
                  outstanding, unless the event causing the 15% threshold to be
                  crossed (A) is a transaction set forth in Section 13(a)
                  hereof, or (B) is an acquisition of shares of Common Stock of
                  the Company pursuant to a tender offer or an exchange offer
                  for all outstanding shares of Common Stock of the Company at a
                  price and on terms determined by at least a majority of the
                  Outside Directors, after receiving advice from one or more
                  investment banking firms, to be (x) at a price that is fair to
                  stockholders (taking into account all factors which such
                  members of the Board deem relevant, including without
                  limitation prices which could reasonably be achieved if the
                  Company or its assets were sold on an orderly basis designed
                  to realize maximum value) and (y) otherwise in the best
                  interests of the Company and its stockholders, or (C) is the
                  execution, delivery, consummation and performance of the 2003
                  Ecolochem Purchase Agreement, or (D) is the sale, disposition,
                  conveyance or other transfer of shares of Common Stock of the
                  Company from one or more Persons, each of whom was a 2003
                  Special Exempt Person immediately prior to such transaction,
                  to a Person who, immediately following such transaction, is a
                  2003 Special Exempt Person, or (E) is the execution, delivery,
                  consummation and performance of the Voting Agreement or the
                  2004 Merger Agreement, then promptly after the date of
                  occurrence of a Section 11(a)(ii) Event, proper provision
                  shall be made so that each holder of a Right (except as
                  provided below and in Section 7(e) hereof) shall thereafter
                  have the right to receive, upon exercise thereof at the then
                  current Purchase Price in accordance with the terms of this
                  Agreement, such number of shares of Common Stock of the
                  Company as shall equal the result obtained by (1) multiplying
                  the then current Purchase Price by the then number of shares
                  of Common Stock of the Company for which a Right was
                  exercisable immediately prior to the first occurrence of a
                  Section 11(a)(ii) Event (whether or not such Right was then
                  exercisable) and (2) dividing that product (which following
                  such first occurrence, shall thereafter be referred to as the
                  "Purchase Price" for each Right and for all purposes of this
                  Agreement) by 50% of the Current Market Price per share of
                  Common Stock of the Company on the date of such first
                  occurrence (such number of shares being referred to as the
                  "Adjustment Shares").

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         9. Section 13(d) is hereby amended and restated in its entirety as
follows:

            (d)   Notwithstanding anything in this Agreement to the contrary,
                  (A) Section 13 hereof shall not be applicable to a transaction
                  described in subparagraph (x) or subparagraph (y) of Section
                  13(a) hereof if (i) such transaction is consummated with a
                  Person or Persons (or a wholly owned Subsidiary of any such
                  Person or Persons) who acquired shares of Common Stock of the
                  Company pursuant to a tender offer or exchange offer for all
                  outstanding shares of Common Stock of the Company which
                  complies with the exception provided for in Section 11(A) (ii)
                  hereof, (ii) the price per share of Common Stock of the
                  Company offered in such transaction is not less than the price
                  per share of Common Stock of the Company paid to all holders
                  of shares of Common Stock of the Company whose shares were
                  purchased pursuant to such tender offer or exchange offer and
                  (iii) the form of consideration being offered to the remaining
                  holders of shares of Common Stock of the Company pursuant to
                  such transaction is the same as the form of consideration paid
                  pursuant to such tender offer or exchange offer, and (B) any
                  transaction that results from the execution, delivery,
                  consummation or performance of the Voting Agreement or the
                  2004 Merger Agreement shall not be a Section 13 Event. Upon
                  consummation of any such transaction contemplated by this
                  Section 13(d), all Rights hereunder shall expire.

         11. Sections 18(a) and 20(c) are hereby amended by inserting the word
"gross" in front of negligence.

         10. Except as amended hereby, the Rights Agreement shall continue in
full force and effect.

         11. The laws of the Commonwealth of Massachusetts shall govern the
interpretation, validity and performance of the terms of this Amendment,
regardless of the law that might be applied under principles of conflicts of
laws.

         12. This Amendment may be executed in two or more counterparts, each of
which shall be deemed an original but all of which, when taken together, shall
constitute one and the same instrument.

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         IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 2
to the Renewed Rights Agreement to be duly executed and their respective
corporate seals to be hereunto affixed and attested, all as of the day and year
first above written.


                                         IONICS, INCORPORATED

                                         By: /s/Stephen Korn
                                             ------------------------------
                                             Name: Stephen Korn
                                             Title: Vice President and
                                             General Counsel


Attest:

                                         EQUISERVE TRUST COMPANY, N.A.

By: /s/ Jeff Seiders                     By: /s/ Tyler Heynes
    --------------------------               ------------------------------
    Name: Jeff Seiders                       Name: Tyler Heynes
    Title: Account Manager                   Title: Managing Director






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