Biological correlations-The hansch approach : a symposium sponsored by the Division of Pesticide Chemistry at the 161st meeting of the American Chemical Society, Los Angeles, Calif., March 31, April 1, 1970 Wade Van Valkenburg, Symposium chairman.

Fate of organic pesticides in the aquatic environment : a symposium sponsored by the Division of Pesticide Chemistry at the 161st meeting of the American Chemical Society, Los Angeles, Calif., March 29-31, 1971

Ozone reactions with organic compounds : a symposium sponsored by the Division of Petroleum Chemistry at the 161 st. meeting of the American Chemical Society, Los Angeles, Calif. March 29-30, 1971. Philip S. Bailey, symposium chairman.

Extractive and azeotropic distillation : based on papers presented at two symposia sponsored by the Division of Industrial and Engineering Chemistry of the American Chemical Society at the 160th meeting ,Chicago, ill., sept.17, 1970 and the 163rd meeting, Boston, Mass, april 14, 1972. Dimitrios P. Tassions symposia chairman.

Bioinorganic chemistry : a symposium co-sponsored by the Division of inorganic Chemistry of the American Chemical Society and the Chemical Institute of Canada at Virginia Polytechnic Institute and State University, Blacksburg, Va. June 22-25, 1970. Raymond dessy ; John Dillard and Lary Taylor, symposium co-chairmen.

Origin and refining of petroleum A symposium co-sponsored by the Division of Petroleum Chemistry of the American Chemical Society and the Canadian Society for chemical engineering of the Chemical Institute of Canada at the ACS-Cıc joint conference, Toronto, Canada, May 25-28, 1970. H. G. McGrath and M. E. Charles symposium chairman.

Pesticides identification at the residue level : a symposium sponsored by the division of Perticide Chemistry of the American Chemical Society at the Joint Conference of the Canada and the American Chemical Society at Toronto, Ontario, Canada May 26-27, 1970. Francis J. Biros symposium chairman.

Anaerobic biological treatment process A symposium sponsored by the division of Water, Air, and Waste Chemistry at the 159 meeting of the American Chemical Society, Houston, tex., Feb. 26, 1970. Federick G. Pohland symposium chairman.

Nonequilibrium systems in natural water chemistry : a symposium sponsored by the Division of Water, Air, and Waste Chemistry of the American Chemical Society at Houston, Texas, February 24-25, 1970. J. D. Hem symposium chairman.

Industrial color technology. A symposium sponsored by the Division of Industrial and Engineering Chemistry at the 156 th meeting of the American Chemical Society, Atlantic City , N. J. Sept. 11, 1968. Ruth M. johnston and Max saltzman, symposium chairman.

Carbohydrates in solution : a symposia sponsored by the Division of Carbohydrate Chemistry at the 162nd meeting of the American Chemical Society Washington, D. C. 1971. Horace S. Isbell symposium chairman.

Platinum group metals and compounds. A symposium sponsored by the division of Inorganic Chemistry at the 158th meeting of the American Chemical Society, New York, N. Y., Sept. 8-9, 1969. U.V. Rao symposium chairman.