AN EXPERIMENTAL STUDY OF THE 

 POISONING OF FISHES BY ILLUMI- 

 NATING GAS WASTES* 



By Dr. V. E. Shelf ord 

 Illinois State Laboratory of Natural History, Urbana, III. 



The work of the various investigators, both American 

 and European, has shown that the various by-products 

 of the manufacture of illuminating gas, as well as the 

 effluent from ammonia sludge beds, lime and iron oxide 

 from purifiers, etc., are poisonous to fishes. In spite of 

 this and their great commercial value they have been 

 and continue to be thrown into streams, especially from 

 the smaller plants. Their marked effect upon the life of 

 certain streams in Illinois led to the investigation of the 

 subject by the writer under the auspices of the State 

 Laboratory. The writer investigated gas liquors, vari- 

 ous mixtures of coal tar compounds and thirty-two or- 

 ganic compounds representing the various groups. Dr. 

 Wells investigated the two oxides of carbon. 



From the usual point of view of the economic zoologist 

 it is sufficient to know that the mixtures thrown into 

 streams are poisonous and the matter is usually allowed 

 to rest there. The pure science investigator however, 

 raised further questions. Various methods of recover- 

 ing and using by-products, remove certain compounds 

 and discharge the residue, — Which compounds are most 

 toxic and which are not poisonous? Killing experiments 

 have usually been performed on fair sized young fish, — 

 What stages in the life histories of food and game fishes 

 are most sensitive? Some compounds are gases in solu- 

 tion which would be expected to diffuse out of water very 

 quickly, — Do they actually escape quickly? Some com- 

 pounds are regarded as insoluble and hence not to be 

 considered, — Are they soluble enough and toxic enough 



*The results of the researches will be published in full in the Bulletin 

 of the Illinois State Laboratory of Natural History. 



