IONICS, INCORPORATED
__________________________________________________________________________
                               19,366 Shares
                               Common Stock
__________________________________________________________________________
    This Prospectus relates to the offer and sale of up to an aggregate of
19,366 shares of Common Stock, $1.00 par value per share (the "Shares"), of
Ionics, Incorporated ("Ionics" or the "Company"), by a selling shareholder
(the "Selling Shareholder").  The Selling Shareholder may sell the Shares
at market prices prevailing at the time of the sale or at prices otherwise
negotiated.  See "PLAN OF DISTRIBUTION."  The Selling Shareholder and
certain persons who purchase shares from it, including broker-dealers
acting as principals who may resell the Shares, may be deemed
"underwriters," as that term is defined in the Securities Act of 1933, as
amended (the "Securities Act").  See "PLAN OF DISTRIBUTION" and "SELLING
SHAREHOLDER."

    None of the proceeds from the resale of the Shares will be received by
the Company.  The Company is responsible for the expenses incurred in
connection with the registration of the Shares and will pay or assume
brokerage commissions or other similar charges incurred in the sale of the
Shares.  The Company has agreed to indemnify the Selling Shareholder
against certain liabilities, including liabilities under the Securities
Act.

    The Company's Common Stock is traded on the New York Stock Exchange
under the symbol "ION."  The last reported sale price for the Common Stock
on March 7, 1997 was $46.75, as reported by the New York Stock Exchange.

    THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY
THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES
COMMISSION NOR HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY
STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY
OF THIS PROSPECTUS.  ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

    No person has been authorized to give any information or to make any
representation other than those contained in this Prospectus in
connection with the offering made hereby, and if given or made, such
information or representation must not be relied upon as having been
authorized by the Company.  Neither the delivery of this Prospectus nor
any sale made hereunder shall, under any circumstances, create any
implication that information herein is correct as of any time subsequent
to the date hereof.

               The date of this Prospectus is March 10, 1997.





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                          AVAILABLE INFORMATION

    The Company is subject to the informational requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and in
accordance therewith files reports, proxy statements and other
information with the Securities and Exchange Commission (the
"Commission").  Such reports, proxy statements and other information are
available for inspection and copying at the public reference facilities
maintained by the Commission at 450 5th Street, N.W., Washington, D.C.
20549, and at the following regional offices of the Commission:  75 Park
Place, 14th Floor, New York, New York 10007 and 219 South Dearborn
Street, Room 1204, Chicago, Illinois 60604.  Copies of such material can
also be obtained from the Public Reference Section of the Commission at
450 5th Street, N.W., Washington, D.C. 20549 at prescribed rates.  The
Common Stock of the Company is listed for trading on the New York Stock
Exchange and such material may also be inspected and copied at the New
York Stock Exchange, 20 Broad Street, New York, New York.

    The Company has filed with the Commission a Registration Statement on
Form S-3 (including all amendments thereto, the "Registration Statement")
under the Securities Act, with respect to the Common Stock offered
hereby.  This Prospectus does not contain all information set forth in
the Registration Statement, certain parts of which are omitted in
accordance with the rules and regulations of the Commission.  For further
information regarding the Company and the Common Stock offered hereby,
reference is hereby made to the Registration Statement and to the
exhibits and schedules filed therewith.  Statements contained in this
Prospectus regarding the contents of any agreement or other document
filed as an exhibit to the Registration Statement are not necessarily
complete, and in each instance reference is made to the copy of such
agreement filed as an exhibit to the Registration Statement, each such
statement being qualified in all respects by such reference.  The
Registration Statement, including the exhibits and schedules thereto, may
be inspected at the public reference facilities maintained by the
Commission at 450 Fifth Street, N.W., Room 1024, Washington, D.C. 20549
and copies of all or any part thereof may be obtained from such office
upon payment of the prescribed fees.

                  INFORMATION INCORPORATED BY REFERENCE

    The following documents filed by the Company with the Commission
pursuant to the Exchange Act are incorporated in this Prospectus by
reference as of their respective dates (File No. 1-7211):

    1. The Company's Annual Report on Form 10-K for the fiscal year ended
       December 31, 1995;

    2. Quarterly Reports on Form 10-Q for the fiscal quarters ended March
       31, June 30, and September 30, 1996;




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    3. The section entitled "Description of Securities to be Registered"
       contained in the Company's Registration Statement on Form 8-A filed
       with the Commission on September 27, 1990.

    All documents subsequently filed by the Company pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act, prior to the termination of
the offering made hereby, shall be deemed to be incorporated by reference
in this Prospectus 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 Prospectus to the extent that a statement contained herein
or in any other subsequently filed document which is also 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 a part of this Prospectus.

    The Company will provide without charge to each person to whom a
Prospectus is delivered, on the written or oral request of such person, a
copy of any or all of the documents described above (other than exhibits to
such documents).  Requests for such copies should be directed to Stephen
Korn, Clerk, Ionics, Incorporated, 65 Grove Street, Watertown,
Massachusetts  02172 (telephone: 617-926-2500).

                                THE COMPANY

    Ionics is a separations technology company involved worldwide in the
manufacture and sale of membranes and related equipment for the
purification, concentration, treatment and analysis of water and
wastewater, in the supply of purified water, food and chemical products,
and in the sale of bottled water and home water purifiers.  The Company's
business activities are divided into three segments:  membranes and related
equipment; water, food and chemical supply; and consumer products.

    Ionics was incorporated in Massachusetts in 1948.  The Company's
principal executive offices are located at 65 Grove Street, Watertown,
Massachusetts 02172 and its telephone number is (617) 926-2500.

                              USE OF PROCEEDS

    The Company will not receive any of the proceeds from the sale of the
shares by the Selling Shareholder.










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                           SELLING SHAREHOLDERS

    The following table sets forth certain information regarding beneficial
ownership of the Shares as of March 10, 1997 and the number of Shares which
may be offered for the account of the Selling Shareholder from time to time:

                                                    Shares To     Shares 
                          Shares Beneficially        be Sold    Beneficially
                                 Owned               in the     Owned After
Selling Shareholder       Prior to the Offering(1)  Offering(1) the Offering
                                                       
Personnel Hygiene                19,366               19,366          0
 Services Limited
Western Industrial Estate
Caerphilly CF83 1XH
Wales
United Kingdom

                              
(1) Based on the average of the closing prices of the Common Stock on the New
York Stock Exchange over the ten trading days prior to the date of the
purchase agreement for the business transaction in which the Selling
Stockholder acquired the Shares.  See "PLAN OF DISTRIBUTION."



    The Selling Shareholder acquired the Shares in a transaction
consummated on March 10, 1997 in which the Company through its English
subsidiary purchased substantially all the assets and the business of
Selling Shareholder's bottled water division.  Prior to the acquisition,
Selling Shareholder through a small division was engaged in bottled water
distribution services in the United Kingdom.  Selling Stockholder continues
to engage in its core business, the provision of commercial washroom
supplies.

                           PLAN OF DISTRIBUTION

    The Shares offered hereby may be sold from time to time by the Selling
Shareholder acting as principal for its own account.  The Company is
responsible for all expenses incurred in connection with the registration
of the Shares, and will pay brokerage commissions or other charges and
expenses incurred in the sale of the Shares.  In addition, the Company has
agreed to indemnify the Selling Shareholder against certain liabilities,
including liabilities under the Securities Act.

    The distribution of the Shares by the Selling Shareholder is not
currently subject to any underwriting agreement.  The Company has agreed
that in the event the total proceeds from the sale of the Shares received
by the Selling Shareholder is less than a specified amount based upon the
stated value of the transaction in which the Selling Shareholder acquired
the Shares, the Company will make a cash payment to the Selling Shareholder
equal to such difference.  

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    The Shares covered by this Prospectus may be sold by the Selling
Shareholder or by pledgees, donees, transferees or other successors in
interest from time to time, and it is the intention of the Selling
Shareholder to complete such sales within one week of the date of this
Prospectus.  Such sales may be made at fixed prices that may be changed, at
market prices prevailing at the time of sale, at prices related to such
prevailing market prices, or at negotiated prices.  Such sales may be
effected in the over-the-counter market, on the New York Stock Exchange or
on any other exchange on which the Shares may then be listed.  The Shares
may be sold by one or more of the following:  (a) one or more block trades
in which a broker or dealer so engaged will attempt to sell all or a
portion of the Shares held by the Selling Shareholder as agent but may
position and resell a portion of the block as principal to facilitate the
transaction; (b) purchases by a broker or dealer as principal and resale by
such broker or dealer for its account pursuant to this Prospectus; and (c)
ordinary brokerage transactions and transactions in which the broker
solicits purchasers.  The Selling Shareholder will effect such transactions
by selling Shares through broker-dealers, and such broker-dealers will
receive compensation in negotiated amounts in the form of discounts,
concessions, commissions or fees which will be paid by the Company.  Such
brokers or dealers and the Selling Shareholder may be deemed to be
"underwriters" within the meaning of the Securities Act, in connection with
such sales, and any commissions received by such broker-dealers may be
deemed to be underwriting compensation.

    State Street Bank & Trust Company, c/o Boston Equiserve, 150 Royall
Street, Canton, Massachusetts 02021, is the transfer agent for the
Company's Common Stock.

                               LEGAL MATTERS

    Certain legal matters with respect to the issuance of the Shares are
being passed upon for the Company by Stephen Korn, Vice President and
General Counsel of the Company.  Mr. Korn beneficially owns 81,555 shares
of Common Stock, which number includes 80,000 shares subject to options, as
to which Mr. Korn has the right to acquire beneficial ownership, and 332
shares (as of September 30, 1996) in the Company's Section 401(k) Plan for
the account of Mr. Korn.

                                  EXPERTS

    The consolidated financial statements and schedules of Ionics,
Incorporated and Subsidiaries as of December 31, 1995 and 1994, and for
each of the years in the three-year period ended December 31, 1995,
incorporated by reference in this Prospectus have been so incorporated in
reliance on the reports of Coopers & Lybrand L.L.P., independent
accountants, given on the authority of that firm as experts in accounting
and auditing.



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No dealer, salesperson or any other
person has been authorized to give any
information or to make any representations
not contained in this Prospectus and, if
given or made, such information or 
representations must not be relied upon
as having been authorized by the Company.
This Prospectus does not constitute an                 19,366 Shares
offer to sell, or a solicitation of an 
offer to sell, any securities other than 
the registered securities to which it               IONICS, INCORPORATED
relates, or an offer to or solicitation
of any person in any jurisdiction where 
such an offer or solicitation would be 
unlawful.  Neither the delivery of this                Common Stock
Prospectus nor any sale made hereunder
shall, under any circumstances, create
an implication that the information 
contained herein is correct as of any
time subsequent to the date hereof.

_______________________________________
                                                    _____________________
      TABLE OF CONTENTS
                             Page                        PROSPECTUS
                                                    _____________________
Available Information......... 2
Information Incorporated by
 Reference.................... 2
The Company................... 3
Use of Proceeds............... 3
Selling Shareholder..........  4
Plan of Distribution.......... 4
Legal Matters................. 5
Experts....................... 5                        March 10, 1997

                                                                         














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