FORM 10-Q

                 SECURITIES AND EXCHANGE COMMISSION

                       Washington, D.C. 20549


(Mark One)

[ X ]    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                  SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended               March 31, 1999          

                                 OR

[   ]    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                  SECURITIES EXCHANGE ACT OF 1934

For the transition period from                  to                  

Commission File Number                   1-7211                     
                  
                        IONICS, INCORPORATED                        
       (exact name of registrant as specified in its charter)

         MASSACHUSETTS                            04-2068530        
 (State or other jurisdiction of                (I.R.S. Employer
  incorporation or organization)                 Identification No.)


         65 Grove Street, Watertown, Massachusetts 02472            
              (Address of principal executive offices)
                             (Zip Code)

                        (617) 926-2500                              
        (Registrant's telephone number, including area code)

                                 NONE                               
        (Former name, former address and former fiscal year, 
                    if changed since last report)
                                              

Indicate by check mark whether the registrant (1) has filed all
reports required to be filed by Section 13 or 15(d) of the Securities
Exchange Act of 1934 during the preceding 12 months (or for such
shorter period that the registrant was required to file such reports),
and (2) has been subject to such filing requirements for the past 
90 days.

YES   X     NO      


Indicate the number of shares outstanding of each of the issuer's
classes of common stock, as of the latest practicable date. 

          Class                   Outstanding at March 31, 1999

 Common Stock, Par Value $1            16,130,150 Shares
/1





                        IONICS, INCORPORATED

                            FORM 10-Q FOR

                    QUARTER ENDED MARCH 31, 1999

                                INDEX


                                                             Page No.

Part I  - Financial Information


          Consolidated Statements of Operations                  2


          Consolidated Balance Sheets                            3


          Consolidated Statements of Cash Flows                  4


          Notes to Consolidated Financial Statements             5


          Management's Discussion and Analysis of Results
          of Operations and Financial Condition                  7




Part II - Other Information                                     12 


          Signatures                                            13 


          Exhibit Index                                         14


          Exhibit 27 - Financial Data Schedule                  15
                                                     (for electronic
                                                      purposes only)












                                - 1 -
/2


<TABLE>
                        PART I - FINANCIAL INFORMATION

                             IONICS, INCORPORATED
                     CONSOLIDATED STATEMENTS OF OPERATIONS
                                  (Unaudited)
               (Amounts in thousands, except per share amounts)
<CAPTION>
                                                      Three Months Ended
                                                           March 31,     
                                                        1999       1998  
<S>                                                   <C>        <C>
Net revenue:
  Equipment Business Group                            $34,439    $33,758
  Ultrapure Water Group                                24,533     18,782
  Consumer Water Group                                 21,859     18,496
  Instrument Business Group                             6,585      7,938
                                                       87,416     78,974
                                                                 
Costs and expenses:
  Cost of sales of Equipment Business Group            24,715     23,431
  Cost of sales of Ultrapure Water Group               18,238     14,006
  Cost of sales of Consumer Water Group                12,283     10,298
  Cost of sales of Instrument Business Group            3,016      2,954
  Research and development                              1,868      1,644
  Selling, general and administrative                  20,109     17,877
                                                       80,229     70,210
Income from operations                                  7,187      8,764
Interest income                                           108        151
Interest expense                                         (130)      (119)
Equity income                                             163        111
Income before income taxes and minority interest        7,328      8,907

Provision for income taxes                              2,382      2,896
Income before minority interest                         4,946      6,011
Minority interest expense                                 274          3
Net income                                            $ 4,672    $ 6,008 
Basic earnings per share                              $   .29    $   .37
Diluted earnings per share                            $   .29    $   .37
Shares used in basic earnings per
  share calculations                                   16,127     16,027

Shares used in diluted earnings per        
  share calculations                                   16,288     16,411

The accompanying notes are an integral part of these financial statements.
</TABLE>

                                      -2-
/3


<TABLE>
                            IONICS, INCORPORATED
                         CONSOLIDATED BALANCE SHEETS
                                 (Unaudited)
                (Amounts in thousands, except share amounts)
<CAPTION>
                                                            March 31,  December 31,
                                                              1999         1998    
<S>                                                         <C>          <C>        
ASSETS                                               
Current assets:
  Cash and cash equivalents                                 $  15,485    $  28,770
  Short-term investments                                          405          359
  Notes receivable, current                                     3,881        4,144
  Accounts receivable                                         110,239      111,844
  Receivables from affiliated companies                         2,388        2,329
  Inventories:
    Raw materials                                              18,689       19,164
    Work in process                                             6,915        8,523 
    Finished goods                                              5,355        3,862
                                                               30,959       31,549

  Other current assets                                          8,056        8,098
       Total current assets                                   171,413      187,093
Notes receivable, long-term                                     8,520        8,824
Investments in affiliated companies                             7,911        7,057
Property, plant and equipment:
  Land                                                          8,388        8,194
  Buildings                                                    43,463       41,594
  Machinery and equipment                                     262,801      259,885
  Other, including furniture, fixtures and vehicles            45,216       44,267
                                                              359,868      353,940
  Less accumulated depreciation                              (162,714)    (158,257)
                                                              197,154      195,683
Other assets                                                   62,009       53,466
       Total assets                                         $ 447,007    $ 452,123

LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Notes payable and current portion 
    of long-term debt                                       $   8,673    $   6,873
  Accounts payable                                             26,896       37,361
  Customer deposits                                             3,689        3,965
  Accrued commissions                                           2,528        2,203
  Accrued expenses                                             33,593       31,884
  Taxes on income                                               4,858        3,648
       Total current liabilities                               80,237       85,934
Long-term debt and notes payable                                1,695        1,519
Deferred income taxes                                          15,216       17,036
Other liabilities                                               2,192        2,036
Stockholders' equity:
  Common stock, par value $1, 55,000,000 authorized shares;
  issued: 16,130,150 in 1999 and 16,116,649 in 1998            16,130       16,117
  Additional paid-in capital                                  157,878      157,571
  Retained earnings                                           184,615      179,943
  Accumulated other comprehensive income                      (10,839)      (7,889)
  Unearned compensation                                          (117)        (144)
       Total stockholders' equity                             347,667      345,598
       Total liabilities and stockholders' equity           $ 447,007    $ 452,123

The accompanying notes are an integral part of these financial statements.
</TABLE>


                                        -3-
/4


<TABLE>
                             IONICS, INCORPORATED
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                  (Unaudited)
                            (Dollars in thousands)
<CAPTION>
                                                             Three Months Ended
                                                                   March 31,      
                                                               1999        1998  
<S>                                                          <C>         <C>
Operating activities:
  Net income                                                 $  4,672    $  6,008
  Adjustments to reconcile net income to net cash
  provided by operating activities:   
     Depreciation and amortization                              6,920       6,459
     Provision for losses on accounts and notes receivable        176         167
     Compensation expense on restricted stock awards               27          27
     Changes in assets and liabilities:
        Notes receivable                                          (64)       (341)
        Accounts receivable                                     1,388       2,962
        Inventories                                               831      (1,128)
        Other current assets                                       78         108
        Investments in affiliates                              (1,102)       (683)
        Accounts payable and accrued expenses                  (9,416)     (3,316)
        Income taxes                                              877       1,262
        Other                                                  (1,704)     (1,952)
           Net cash provided by operating activities            2,683       9,573
Investing activities:  
  Additions to property, plant and equipment                   (9,031)     (6,175)
  Disposals of property, plant and equipment                      214         439
  Acquisitions, net of cash acquired                           (8,394)          -
  Purchase of short-term investments                              (45)       (751)
           Net cash used by investing activities              (17,256)     (6,487)
Financing activities: 
  Principal payments on current debt                           (5,862)     (9,480)
  Proceeds from issuance of current debt                        7,717       1,205
  Principal payments on long-term debt                           (518)         (4)
  Proceeds from issuance of long-term debt                        116         441
  Proceeds from stock option plans                                275       1,512
           Net cash provided/(used) by financing activities     1,728      (6,326)
Effect of exchange rate changes on cash                          (440)          8
Net change in cash and cash equivalents                       (13,285)     (3,232)
Cash and cash equivalents at beginning of period               28,770      25,787
Cash and cash equivalents at end of period                   $ 15,485    $ 22,555

The accompanying notes are an integral part of these financial statements.
</TABLE>
                                      -4-
/5


                        IONICS, INCORPORATED

             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1.  In the opinion of Ionics, Incorporated (the "Company"), the
    accompanying consolidated financial statements contain all
    adjustments (consisting of only normal, recurring accruals)
    necessary to present fairly the consolidated financial position of
    the Company as of March 31, 1999 and December 31, 1998, the
    consolidated results of its operations for the three months ended
    March 31, 1999 and 1998 and the consolidated cash flows for the
    three months then ended.

2.  The consolidated results of operations of the Company for the
    three months ended March 31, 1999 and 1998 are not necessarily
    indicative of the results of operations to be expected for the
    full year.

3.  Reference is made to the Notes to Consolidated Financial
    Statements appearing in the Company's 1998 Annual Report as filed
    on Form 10-K with the Securities and Exchange Commission.  There
    have been no significant changes in the information reported in
    those Notes, other than from the normal business activities of the
    Company, and there have been no changes which would, in the
    opinion of Management, have a materially adverse effect upon the
    Company.

4.  Certain prior year amounts have been reclassified to conform to
    the current year presentation with no impact on net income.

5.  Earnings per share (EPS) calculations:
<TABLE>
<CAPTION>
                                              (Amounts in thousands, except per share amounts)

                                  For the period ended March 31, 1999    For the period ended March 31, 1998
                                     Net                  Per Share          Net                  Per Share
                                    Income      Shares      Amount          Income      Shares      Amount  
<S>                               <C>         <C>        <C>             <C>          <C>        <C>
    Basic EPS
      Income available to common    $4,672      16,127      $ .29          $6,008       16,027      $ .37
        stockholders
      Effect of dilutive stock
        options                          -         161                          -          384      
                                  ______________________                 _______________________
    Diluted EPS                     $4,672      16,288      $ .29          $6,008       16,411      $ .37 
</TABLE>
6.  Comprehensive Income

    The Company has adopted the Statement of Financial Accounting Standards 
    ("SFAS") No. 130, "Reporting Comprehensive Income," which establishes 
    standards for the reporting and display of comprehensive income and its 
    components in general purpose financial statements for the year ended 
    December 31, 1998.  The table below sets forth "comprehensive income" 
    as defined by SFAS No. 130 for the three month periods ended March 31, 
    1999 and 1998.
<TABLE>
<CAPTION>
                                    (Amounts in thousands)

                                  Three Months Ended March 31,
                                   1999              1998 
<S>                               <C>               <C>
    Net income                    $4,672            $6,008
    Other comprehensive income,
      net of tax:
         Translation adjustments  (2,950)             (194)
    Comprehensive income          $1,722            $5,814
</TABLE>
                                    -5-
/6




7.  In 1998, the Company adopted SFAS No. 131, "Disclosures about
    Segments of an Enterprise and Related Information."  At the end
    of 1998, the Company changed from three reportable segments to
    four reportable "business group" segments corresponding to a
    "business group" structure which was put into place in the
    latter part of 1998.  Segment information for the prior year has
    been restated to reflect this change.  As of March 31, 1999, no
    changes have been made to the basis of segmentation or the
    measurement of profit or loss from that which was reported in
    the Company's 1998 Annual Report as filed on Form 10-K with the
    Securities and Exchange Commission, and there were no material
    changes to total assets by segment.

    The following table summarizes the Company's operations by the
    four business group segments and "Corporate."  

<TABLE>
<CAPTION>
                                   Equipment    Ultrapure   Consumer   Instrument
                                   Business       Water       Water     Business
Dollars in Thousands                Group         Group       Group       Group    Corporate      Total 
<S>                                <C>          <C>         <C>        <C>         <C>          <C>
1999
Revenue - unaffiliated customers   $ 34,439     $ 24,533    $ 21,859   $  6,585    $      -     $ 87,416
Inter-segment transfers                 319          197           -        194        (710)           -
Gross profit                          9,724        6,295       9,576      3,569           -       29,164
Research and development                                                                          (1,868)
Selling, general and administrative                                                              (20,109)
Interest income                                                                                      108
Interest expense                                                                                    (130)
Equity income                                                                                        163
Income before income taxes
    and minority interest                                                                          7,328

                                                                                                        

1998
Revenue - unaffiliated customers   $  33,758    $ 18,782    $ 18,496   $  7,938    $      -     $ 78,974
Inter-segment transfers                  746          77           -        196      (1,019)           -
Gross profit                          10,327       4,776       8,198      4,984           -       28,285
Research and development                                                                          (1,644)
Selling, general and administrative                                                              (17,877)
Interest income                                                                                      151
Interest expense                                                                                    (119)
Equity income                                                                                        111
Income before income taxes
    and minority interest                                                                          8,907

</TABLE>







                                                    -6-
/7


               MANAGEMENT'S DISCUSSION AND ANALYSIS OF
             RESULTS OF OPERATIONS AND FINANCIAL CONDITION  


Results of Operations

Comparison of the Three Months Ended March 31, 1999
with the Three Months Ended March 31, 1998

Revenues for the first quarter of 1999 increased 10.7%, and net
income decreased by 22.2% compared to the results of the first
quarter of 1998.  The decline in net income was primarily due to
a reduction in earnings before interest, taxes and minority
interest (EBIT) in the Instrument Business Group.  This reduction
was attributable to lower revenues, unfavorable overhead
absorption due to lower volume and a higher proportion of lower
margin service revenue for the Instrument Business Group in the
first quarter of 1999.  Partially mitigating this decline was a
significant increase in EBIT in the Ultrapure Water Group.  The
Ultrapure Water Group benefited from increased sales in the first
quarter of 1999 in comparison to the first quarter of 1998.

Total revenues were $87.4 million in the first quarter of 1999
compared with $79.0 million in the first quarter of 1998.
Revenues were higher in the Ultrapure Water Group, the Consumer
Water Group and the Equipment Business Group, while revenues
declined in the Instrument Business Group.  The Company's three
acquisitions made at the beginning of the first quarter of 1999
did not provide significant revenues as these businesses were
added to provide the Company with access to new markets rather
than significant initial sales volume.

The Equipment Business Group's revenues increased by 2.0% in the
first quarter of 1999 as compared to the first quarter of 1998.
This increase came from higher capital equipment sales while
water supply sales of this Group remained relatively flat.

The revenues of the Ultrapure Water Group increased by $5.8
million in the first quarter of 1999 compared to the first
quarter of 1998.  This increase reflects the shipment of orders
largely received in 1998.  Revenues for this Group were down
significantly in 1998 primarily due to a slowdown in capital
spending by the microelectronics industry. 

The 18.2% increase in the Consumer Water Group's revenues from
the first quarter of 1999, compared with the first quarter of
1998, was due to growth in both bottled water and home water
products.  In addition, through the acquisition of Aquarelle SA,
the Company entered the French bottled water market at the
beginning of 1999.

The Instrument Business Group's revenues declined by $1.4 million
in the first quarter of 1999 as compared to the first quarter of
1998.  This Group benefited from strong demand in the first part
of 1998 due to the implementation of United States Pharmacopoeial
Convention's USP 23 which mandated the monitoring of Total
Organic Carbon (TOC) in water processed by the pharmacuetical
industry.


                               -7-
/8



Cost of sales as a percentage of revenues was 66.6% in the first
quarter of 1999 compared to 64.2% in the first quarter of 1998.

Cost of sales as a percentage of revenues increased in the first
quarter of 1999, compared to the first quarter of 1998, for the
Equipment Business Group, the Consumer Water Group and the
Instrument Business Group, while such percentage for the
Ultrapure Water Group decreased slightly in the first quarter of
1999 compared with the first quarter of 1998.  The increase in
the Equipment Business Group primarily reflected a shift in the
mix of contracts to the lower margin equipment businesses and to
relatively stronger margins for wastewater equipment sales in the
first quarter of 1998.  The Consumer Water Group's slight
increase in cost of sales in the first quarter of 1999, compared
to the first quarter of 1998, primarily reflected a lower than
normal cost of sales in the first quarter of 1998 due to a modest
inventory adjustment which favorably impacted the consumer bleach
business.  This increase was offset by margin improvement in the
home water business.  The increase in the cost of sales as a
percentage of revenues in the Instrument Business Group was due
to an increase in manufacturing overhead, including relocation to
a larger facility, as well as a higher portion of revenues for
the quarter derived from lower margin service business.  These
increases were offset by a slight decrease in cost of sales for
the Ultrapure Water Group in the first quarter of 1999, compared
to the first quarter of 1998, because of a more favorable mix of
jobs supported by a strong service business with favorable
margins.

Operating expenses as a percentage of revenues were 25.1% in the
first quarter of 1999 and 24.7% in the first quarter of 1998.
The increase in operating expenses as a percentage of revenues
primarily reflected the decline in sales in the Instrument
Business Group and more rapid growth in the Consumer Water Group
which generally has higher operating expenses and higher gross
margins than do the capital equipment businesses.  The Consumer
Water Group also had higher operating expenses in the first
quarter of 1999 due to start-up expenses related to Aqua Cool's
expansion into the French market and expenses for a major
computer system implementation for the Aqua Cool business in the
United States.  In addition, operating expenses increased due to
expanded marketing initiatives as well as the Company's continued
commitment to investment in its research and development
programs.

Interest expense of $0.1 million and interest income of $0.1
million in the first quarter of 1999 remained relatively
consistent with interest expense and income in the first quarter
of 1998.  

Financial Condition

Working capital decreased $10 million during the first three
months of 1999 while the Company's current ratio decreased
slightly to 2.1 at March 31, 1999 from 2.2 at December 31, 1998.
Cash provided from net income and depreciation totaled $11.6
million during the first three months of 1999, while the primary
uses of cash were for additions to property, plant and equipment,
three acquisitions at the beginning of the first quarter of 1999
and a significant reduction in accounts payable.  Significant
capital expenditures were incurred to support growth in bottled
water operations, for new manufacturing and distribution
facilities and for "own and operate" facilities.

                               -8-
/9





At March 31, 1999 the Company had $15.5 million in cash and cash
equivalents, a decrease of $13.3 million from December 31, 1998.
Accounts payable decreased by $10.5 million, and other assets
increased by $8.5 million, primarily due to goodwill from the
three acquisitions made at the beginning of the first quarter of
1999.  Notes payable and long-term debt increased by $2.0
million.  The Company believes that its cash and cash
equivalents, cash from operations, lines of credit and foreign
exchange facilities are adequate to meet its currently
anticipated needs.

Year 2000 Readiness Disclosure and Related Information

The Company's State of Readiness

The Company has undertaken a program to assure that its computer
software and systems (including information technology (IT) and
manufacturing systems), facilities and products will be able to
distinguish 21st century dates from 20th century dates (so-called
"Year 2000 (Y2K) Compliance or Compliant").  The Company's
program is divided into the following three phases:

Phase One - Inventory and Planning

The Company completed this phase in July 1998.  In this phase,
the Company inventoried all hardware and software that
potentially is susceptible to Y2K problems, prepared plans for
assessing compliance and completing remediation, and prepared
vendor compliance letters.

Phase Two - Assessment

In this phase, the Company is assessing which of its systems and
products are Y2K Compliant.  The Company has requested compliance
statements from hardware and software vendors, supply
manufacturers and service trading partners and has received
responses from many vendors and has not discovered any
significant compliance problems.  This phase also includes the
planning for remediation of non-compliant systems.  The Company
anticipated the completion of this phase by the end of the first
quarter of 1999.  To date, approximately 95% of this phase is
complete.

Phase Three - Remediation and Testing

In this Phase, the company will deploy plans for elimination,
upgrade, replacement or modification of non-compliant systems and
products and test compliance.  The Company has scheduled
completion of this phase by the third quarter of 1999.







                               -9-
/10




The Company's core operating (IT and manufacturing) system for
its headquarters operations is not yet Y2K Compliant.  The
Company is currently pursuing a remediation plan for this system,
has made significant progress, and expects to have it completed
by mid-1999.  The Company's bottled water accounting system in
the United States is not yet fully Y2K Compliant.  The Company
has purchased a new integrated distribution and accounting
system, which management believes will significantly enhance its
bottled water operations.  This new system is Y2K Compliant and
implementation is scheduled for completion by the end of the
third quarter of 1999.  Individual bottled water business
locations are running this new system as it is implemented, which
the Company believes may reduce the risks associated with
potential Y2K non-compliance should implementation not be fully
completed by the end of 1999.

The Company's other IT systems are not uniform across all
operations and locations.  The systems for all non-headquarters
operations have been reviewed.  The Company is currently
implementing new Y2K Compliant IT systems at two major locations
in the U.S. Completion of implementation of these systems is
expected by mid-1999.  The Company has either completed
remediation or implemented new IT systems which are Y2K Compliant
at its other significant non-headquarters operations.

Remediation or replacement of IT systems at other locations is
under way and is expected to be completed by mid-1999.  The
Company believes that failure of these systems to become Y2K
Compliant would be unlikely to have a material impact on the
Company due to the relatively small size of these operations and
the opportunity to perform relevant tasks manually.

The Company's assessment plan includes assessment of Y2K
Compliance of non-information technology (non-IT) components
including the Company's membrane-related equipment, "own and
operate" equipment, other products, manufacturing equipment and
facilities.  Substantial progress has been made in these areas,
and assessment is almost complete.

The Company is obtaining compliance statements from vendors of
both IT and non-IT systems and is revising its vendors' status on
an on-going basis based upon information it is receiving.  The
Company is working with its most important vendors to resolve
remediation and compliance problems as they are identified.

Costs to Address Y2K Issues

The Company's assessment and remediation of Y2K Compliance issues
is anticipated to cost approximately $1.5 million, excluding the
cost of new systems implementation.  Expenses to date of
approximately $900,000 are consistent with such expectations.
The Company does not currently expect that actual Y2K expenses
finally incurred will materially exceed its estimate.



                              -10-
/11



Risk of the Company's Y2K Issues

If the Company fails to achieve Y2K Compliance in all its
systems, the Company could lose the ability to process certain of
its customers' orders, manufacture products or provide services
to customers until compliance is achieved or a means to work
around the failure is implemented.  However, most of the
Company's businesses process a small number of relatively large
transactions, mitigating the short-term dependence on information
systems.  Also, because the Company's systems are not uniform
across the Company, it is anticipated that any failure would not
be Company-wide.  Furthermore, a failure to fill an order may not
necessarily result in complete loss of the order.  Some orders
could be filled through alternative methods within a relatively
short period.  Nevertheless, any disruption in order fulfillment,
manufacturing or the provision of services to customers could
result in some loss of revenue or claims against the Company.
Moreover, there is uncertainty as to whether the Company may
experience any disruption in these areas as a result of
uncertainty concerning the Y2K readiness of third-party vendors.
If disruption in any of these areas resulting from Y2K non-
compliance is greater than anticipated, the loss of revenue could
be material.

Contingency Plans

The Company plans to complete contingency plans by the end of the
third quarter of 1999 to deal with possible failures in systems
which it determines may not achieve Y2K Compliance on a timely
basis.

Quantitative and Qualitative Disclosures about Market Risk

Derivative Instruments and Market Risk

There has been no material change in the information reported in the
Company's 1998 Annual Report as filed on Form 10-K with the Securities
and Exchange Commission with respect to these risk matters.

Forward-Looking Information

Safe Harbor Statement under Private Securities Litigation Reform Act of 1995

The Company's future results of operations and certain statements
contained in this report, including, without limitation, "Management's
Discussion and Analysis of Results of Operations and Financial
Condition," constitute forward-looking statements.  Such statements are
based on management's current views and assumptions and involve risks,
uncertainties and other factors that could cause actual results to
differ materially from management's current expectations.  Among these
factors are acceptance of new products and price pressures; risk of
nonpayment of accounts receivable; risks associated with foreign
operations; the ability of the Company to achieve Y2K Compliance in
accordance with its current program including the ability of the
Company to ascertain and plan for compliance issues of third-party
vendors; risks involved in litigation; regulations and laws affecting
business in each of the Company's markets; market risk factors, and
other risks and uncertainties described from time to time in the
Company's filings with the Securities and Exchange Commission. 

                                 -11-

/12




                      PART II - OTHER INFORMATION


Item 6.  Exhibits and Reports on Form 8-K

(a)  Exhibits

     None

(b)  Reports on Form 8-K

     No reports on Form 8-K were filed with the Securities and
Exchange Commission during the quarter ended March 31, 1999.  

     All other items reportable under Part II have been omitted as
inapplicable or because the answer is negative, or because the
information was previously reported to the Securities and Exchange
Commission.

































                                -12-
/13





                           SIGNATURES



     Pursuant to the requirements of the Securities Exchange Act
of 1934, the registrant has duly caused this report to be signed
on its behalf by the undersigned thereunto duly authorized.



                                 IONICS, INCORPORATED



Date:   May 14, 1999        By: /s/Arthur L. Goldstein                  
                                 Arthur L. Goldstein
                                 Chairman and Chief Executive Officer
                                 (duly authorized officer)



Date:   May 14, 1999        By: /s/Robert J. Halliday                   
                                 Robert J. Halliday
                                 Vice President, Finance and
                                 Chief Financial Officer
































                                -13-
/14







                            EXHIBIT INDEX

                                                       Sequentially
                                                         Numbered
Exhibit                                                    Page

27.0      Financial Data Schedule                           16
                                                      (for electronic
                                                       purposes only)









































                                -14-
/15