:uJ, 



STAl^E BOARD OF AGRICULTURE. 



ammonia and carbon dioxide would be driven off from the beetles, (i. 

 e., very little more of either gas could be obtained by further boiling.) 

 The ammonia was caught by the acid in "C." This acid became too warm 

 to retain any of the carbon dioxide which was therefore carried over 

 and caught in "b" and "a." The excess of the -^ sulphuric acid in 

 "C," not neutralized by ammonia driven off from "D" was titrated 

 against ^ ammonia water. Thus, the number of cubic centimeters of 



^Q ammonia given off from the insects could be found, and that num- 

 ber times the factor 0.0017 gave the number of grams of ammonia, from 



Fin. G. Form of apparatus u.sed in distilling off NH3 and COj that had become fixed in in.sects 



previously confined in ammonia-air mixture. 



which it was easy to determine the volume — one gram of ammonia being 

 equivalent to 1309.7 c. c. of the gas at 0° C and 760 m. m. mercury 

 pressure. 



The carbon dioxide caught in "a" and "b'' was determined in the 

 usual manner. 



Now, from several experiments in which untreated insects had been 

 distilled in "D" it was found that a very close average of 0.6 c. c. of 

 carbon dioxide per gram of the beetles was driven off in one hour — 

 after one hour very little carbon dioxide could be driven off by fuai;her 

 boiling — i. e., that much carbon dioxide was normally in the living 

 beetles which had been breathing pure air. When obtaining the respira- 

 tory ratio in air, this normal amount of carbon dioxide would be left 



