389 



A. Nitrogcnizcd Compounds. 



Of this group ammonia and its salts are of constant occurrence. 

 The vokime of ammonia in the drip from the Champaign holder inlet 

 is usually about 200% of the volume of liciuid. The salts are abundant 

 in all parts of an ordinary plant. Such well known compounds as 

 ethvlamine, aniline, pyridine, and quinoline belong to this group. 



B. SidpJiurettcd Compounds. 



To this group belong such well known compounds as hydrogen 

 sulphide, sulphur dioxide and carbon bisulphide, and the less well 

 known licjuid thiophene. which is common as an impurity in benzene. 

 All are very poisonous. 



C. Oxygenized Compounds. 



In this group are included such well known substances as acetone, 

 acetic and benzoic acids, and phenol and the cresols. 



D. Hydrocarbons. 



To this group belong the solids phenanthrene, anthracene, naphtha- 

 lene, and the volatile liquids, xylene, toluene, benzene, etc. The gases 

 are numerous, including acetylene, ethylene, and methane. 



E. Carbon Oxides. 



These are the two well know^n gases carbon dioxide and monoxide. 



Gas waste from plants which remove only the heavy tar may be 

 regarded as containing all of these compounds. The dissolved gases 

 of course escape into the air but are held in great quantity and given 

 ofif slowly from the tarry materials. 



V. Toxicity of Wastes from the Champaign Plant. 



The toxicity of different samples differs greatly, some samples be- 

 mg ten or twelve times as toxic as others. This depends upon the 

 interval since the main was pumped and whether it comes from the 

 inlet or the outlet to the holder. Attempts were made to determine 

 the toxicity of waste by means of indicators and acid. There appears 

 to be no relation between the amount of normal acid required to pro- 

 duce a red color with methyl orange and toxicity to fish. The same 

 difficultv was encountered when normal alkali was used. Likewise 



