398 



methyl orange indicator. It tends to paralyze the terminations of the 

 motor nerves of the frog. In the case of fishes, it shows no important 

 differences from ammonia. Reactions are usually positive to strong 

 concentrations and negative to weak ones (Chart II, graph 17). 



Ammonium sulphate. 



It is present in waste in small quantities. A solution was made 

 and tested as in the case of ammonium chloride. It is much less toxic 

 than the carbonate. Its toxicity is greatest in the presence of car- 

 bonates (Wells '15). When all the carbonates have been transformed 

 into sulphates it becomes less toxic. Fishes are positive in reaction to 

 fatal concentrations and negative to weak concentrations (Chart II, 

 graph 18). 



Ammonium sulphocyanate. 



It occurs in some quantities in first condensers and washers. A 

 solution was made by weighing out the salt and dissolving it in dis- 

 tilled water. The strength of the solution was determined by adding 

 a strong alkali and distilling off the ammonia into standard acid and 

 titrating with standard alkali. It is much more toxic than the chloride. 

 The fish showed no striking symptoms. Fishes are positive to fatal 

 concentrations (Chart II, graphs 19 and 20). 



Ammonium ferrocyanide. 



It occurs in small quantities in liquor from last condensers. The 

 general method of experimentation and determination was the same 

 as in the case of ammonium sulphocyanate. The physiological effects 

 are not striking on the fishes. Fishes are positive to fatal concentra- 

 tions (Chart III, graph 21). 



Bthylamine. 



Five grams of Kahlbaum's hermetically sealed product was broken 

 into two liters of water but with an obvious loss. Dilutions from this 

 were made and tested. Its effect appears to be in a general way like 

 that of ammonia. Fishes were positive in a single experiment (Chart 

 III, graph 22). 



Aniline. 



A sample of Kahlbaum's, slightly brown, was used, the proper dilu- 

 tions being made by adding a small quantity from a burette to 4 liters 



