EXPERIMENT STATION BULLETINS. 



573 



iu the insects at the end. Therefore, in finding the amount of carbon 

 dioxide produced by the insects under the influence of ammonia, 0.0 

 c. c, for every gram weight of beetles used was subtracted from the 

 volume of carbon dioxide driven off during the process of distillation. 

 The remainder plus any carbon dioxide found in the respired air was 

 taken as the amount produced by the insects dmring the experiment. 

 Thus, all the necessary data desired was at hand. 



Table VII records some important results given in six experiments 

 carried out by the method just described. The beetles used in Nos. 

 4, 5 and 6 were taken from the same lot as those used in the fiirst three 

 experiments and no doubt would have given similar respiratory quo- 

 tients in air. Indeed, one determination of the "quotient" was made 

 in air for the beetles used in No. 6, and it was 0.75. 



TABLE VII. 



CO 2 



Influence of ammonia gas in air upon . 



O2 



When ammonia was used, the respiratory ratio as well as the quo- 

 tient is given in the table. The denominator of the ratio in each case 

 is the nuttnber of cubic centimeters of oxygen used by the insects dur- 

 ing the experiment; the numerator, it is believed, equals the number 

 of cubic centimeters of carbon dioxide produced by the insects, under 

 Hie influence of ammonia, during the experiment. The method of ob 

 laining the values of both numerator and denominator has already been 

 described. 



As ma}' be seen, when carbon dioxide appeared in the respired air. 

 all or practically all free ammonia had di8api)eared from tliat air — 

 in Nos, 1 and 2 a slight amount of ammonia appeared to be still present. 



In case practically no ammonia gas was present at the end of the 



