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VICTOR E. SHELFORD AND W. C. ALLEE 



for temperature, pressure and tension of aqueous vapor (Hempel 

 '02, p. 64). The results of the analyses are shown in table 1 A. 



TABLE 1 A 



Arialyses of commercial gases used in experiments 



b. Hydrogen, ammonia and methane 



No experiments were performed with hydrogen. Shull ('12) 

 has found that hydrogen manufactured electrolytically and on 

 sale by the Lind Air Products Company conamonly contains from 

 2 to 4 per cent of oxygen. Hydrogen which is generated in the 

 usual way and used for the purpose of displacing oxygen, prob- 

 ably always contains a quantity of oxygen. The ammonia used 

 in these experiments was the chemically pure solution diluted 

 and allowed to flow into the apparatus at a uniform rate. The 

 effect of methane upon animals has probably not been studied. 

 Crocker and Knight ('12) manufacture it and have found that 

 it slightly affects plant growth. 



c. Bubbling gas through water 



Gas was bubbled through water in order to learn something of 

 the cause of gas bubble disease (Marsh and Gorham '05) which 

 developed in the stock of fish while the experiments were being 

 conducted. Under these conditions, not one but several factors 

 were varied. The gas which is bubbled through is added to the 

 water and each bubble being a partial vacuum for the other 

 gases, takes them up until they are nearly exhausted from the 

 water. The results of some of the bubbling experiments are 



