Trout Breeding. 25 



they run into them. Lime from paper mills, the chlo- 

 ride, I believe, used for bleaching, is deadly on the side 

 of the river in which it flows. The paper mills which 

 make their sto6k from wood pulp do not use one-tenth 

 the lime for bleaching which the other mills require. 



The Massachusetts Commissioners of Fisheries, in 

 their report for 1866, say : 



"To state^in a comprehensive way what is the effect 

 of certain impurities in water, is by no means easy. 

 Even supposing the mixtures thus made (refuse from 

 factories) to be constant and stable (which they are not) , 

 their effect upon different animal and vegetable organ- 

 isms would be quite variable. Chemical analysis is no* 

 such great helper in the difficulty as might be supposed. 

 A science that is still so imperfect as to call starch and 

 sugar the same thing, and that cannot tell a good wine 

 from bad, is hardly a reliable support in testing the fine 

 questions of animal likes and dislikes. . . . The 

 sole way, therefore, of arriving at any result is, to make 

 a great number of experiments upon the animals, and 

 under the conditions required. To make such a series 

 of experiments did not lie within the power of the Com- 

 missioners, but, to establish some main facts, a few cases 

 were tested, as follows : 



Experiment A. A young bream (Pomotis vulgaris) 

 put in a glass of water, to which 1-200 in bulk of sul- 

 phuric acid was added, died in four minutes. 



Experiment B. The same species, in a similar glass 

 of water, to which i-ioo in bulk of concentrated solu- 

 tion of soap was added, died in two minutes. 



Experiment C. A young shiner {Leuciscus cryso- 

 leucas) in a glass of water, to which 1-500 in bulk of 

 chloride of lime was added, was distressed, but did not 

 die for seven minutes. 



