224 American Fisheries Society. 



Even at concentrations where the velocity curve of colloidal 

 sulphur is no more a straight line, the toxicity of colloidal sulphur 

 solution seems to be greater than lime-sulphur mixture, which is 

 a compound of sulphur and lime. It will be seen from the table 

 that the survival time varied within a rather wide range. As has 

 already been stated, the samples were not very uniform in nature. 

 The variation in toxicity is considered to be due chiefly to this fact 

 and to the variation in the size of the fish. 



ACKNOWLEDGMENTS. 



The present study was suggested by Dr. V. E. Shelford and the 

 experiments were conducted under his direction. The writer wishes 

 to thank him heartily for his kindness in allowing the use of his 

 laboratory equipment and for extending many courtesies, includ- 

 ing the furnishing of references regarding the occurrence of hydro- 

 gen sulphide in water. The writer is also much indebted to Dr. 

 Carver for his kind suggestion and for supply of conductivity 

 water. 



BIBLIOGRAPHY. 



(1) Sabbatani, L. Pharmacological Action of Colloidal Sulphur. 

 Arch, inter. Pharmacodyn., 18:373-391. Abstract: Chem. Abstract, 3:1413, 

 1909. 



(2) Taylor, W. W. The Chemistry of Colloids, 2nd Ed., 1921; com- 

 pare also Raflfo, M. Ueber Kolloiden Schwefel. Zeitschr. f. Chem. u. 

 Indus, d. Kolloid., 2:358-360. 



(3) Murray, J., and Hjort, J. The Depths of the Ocean. London, 

 1912. 



(4) Shelford, V. E. An Experimental Study of the Effects of Gas- 

 waste Upon Fishes. Bull. 111. St. Lab. of N. H. 11:380-412, 1917. 



(5) Raffo, M. and Mancini, J. Beitrag zur Kenntnis des Kolloiden 

 Schwefels. Zeitschr. f. Chem. u. Indust. d. Kolloid., 9:58-61, 1911. 



(6) Harukawa, C. Studies on Lime-Sulphur Mixtures. Berichte d. 

 Ohara Institute f. Landw. Forsch., Japan, 2:1-20, 1921. 



(7) Powers, E. B. The Goldfish (Carassius carassius) as a test animal' 

 in the study of toxicity. Illinois Biolog. Monogr. IV, 2, 1917. 



