42 ILUNOIS BIOLOGICAL MONOGRAPHS [162 



THE EFFECT OF TEMPERATURE UPOX THE RESISTANCE OF GOLDFISH 



A few experiments were run to determine the effect of temperature on 

 the toxic activity of a substance on the goldfish. It is shown by Tables 

 XXXIII, XXXIV, and XXXV that the survival time of the goldfish in a 

 constant concentration of a substance is lowered by a rise in temperature. 

 This agrees with other workers on toxicity. See bibliography for citations. 

 No attempt was made to find the relation between temperature and the toxic 

 activity of a substance. See discussion of Warren's (1900) temperature toxicity 

 curve, page 52. 



TOXICITY AND THE EXPRESSION OF RELATIVE TOXICITY 



The relative toxicity of the respective elements has long interested the 

 chemist. The views of workers on the toxic activity of the elements have 

 varied from time to time to fit any newly discovered physico-chemical con- 

 ception of the properties of the elements. James Blake (1883, 1887) associated 

 the physiological action of the elements of the isomorphous groups with their 

 atomic weights. Botkin (1885) suggested a relation between the toxic acti\'ity 

 of the elements and their position in the periodic sj'stem. Pauh (1903), 

 Kahlenberg and True (1896), Kahlenberg and Austin (1900), Loeb (1902), and 

 Mathews (1903, 1907) held that the toxic activity of a substance is dependent 

 either upwn the free electrical charge or the atom itself while in the atomic 

 state. Richet (1881) and Rabuteau have suggested that toxicity is a 

 function of the solubiUty of the substance. Mathews (1904) has related 

 toxicity to the solution tension of the ion. While, finally, Bert (1871), Garrey 

 (1905), Kfizeneck^ (1916) and others claim that the toxic effect of at least 

 certain elements to fresh water animals is due primarily to osmotic pressure. 

 After all these and other suggestions such as coagulation of the protoplasm, 

 ionic combination, either physical or chemical, with the protein of the proto- 

 plasm, and the change of permeability of the cell membrane, the cause of 

 toxicity is still an open question. Aside from the divergence of opinions as 

 to the cause of the active properties of the elements there has been no absolute 

 agreement on relative toxicity itself. In this work some attempt has been 

 made to determine the relative toxic values of certain of the alkah and alkaline 

 earth metals when in combination with CI and NO3. First it is obvious that 

 it is necessary to have some standard of measure of the elements themselves. 

 The elements will be arranged differently from the same data when considered 

 by actual weight of the element, actual weight of the salt, molecular concen- 

 tration, and normahty. This of itself explains certain of the disagreements 

 among workers, though after all the elements are reduced to a common standard 

 of measure there is still a wide divergence in relative toxicity as reported by 

 different workers. Osterhout (1915) has pointed out that " the relative toxicity 

 of two substances may depend very largely on the stage of the reaction at which 

 the measiirement is made"; i.e., the criterion employed. Osterhout objects 



