EXHIBIT 25 POWER OF ATTORNEY We, the undersigned officers and directors of Ionics, Incorporated (the "Company"), hereby severally constitute Arthur L. Goldstein and Stephen Korn, and each of them, to sign for us, and in our names in the capacities indicated below, the Annual Report on Form 10-K of the Company for the fiscal year ended December 31, 1993, and any and all amendments to such Annual Report, hereby ratifying and confirming our signatures as they may be signed by our attorneys to such Annual Report and any and all amendments thereto. Witness our hands on the respective dates set forth below. Signature Title Date /s/William L. Brown Director March 28, 1994 William L. Brown /s/Arnaud de Vitry d'Avaucourt Director March 28, 1994 Arnaud de Vitry d'Avaucourt /s/Lawrence E. Fouraker Director March 28, 1994 Lawrence E. Fouraker /s/Samuel A. Goldblith Director March 28, 1994 Samuel A. Goldblith /s/Arthur L. Goldstein Chairman of the Board March 28, 1994 Arthur L. Goldstein of Directors, Chief Executive Officer and President (Principal Executive Officer) /s/Kachig Kachadurian Director March 28, 1994 Kachig Kachadurian /s/William E. Katz Director March 28, 1994 William E. Katz Director Robert B. Luick Director John J. Shields /s/Mark S. Wrighton Director March 28, 1994 Mark S. Wrighton /s/Allen S. Wyett Director March 28, 1994 Allen S. Wyett /83