On the Respiration of Atmospheric Air. 53 



oxygen gas. But hitherto we had only had probabilities, or 

 results of which the solidity could not be properly ascer- 

 tained. It is to Davy that we owe an exact and well founded 

 knowledge of the active part which azotic gas performs in 

 the act of respiration. But the more that these results were 

 pew and interesting, the more they deserved to be confirmed 

 by the agreement of the experiments of other chemists; and 

 it was from this view that I undercook, last winter, a series 

 of experiments on the respiration of atmospheric air, and 

 the respiration of the gaseous oxide of azote, of which I 

 submitted the principal results to the National Institute. 



Experiments on the Respiration of Atmospheric Air and 

 of Oxygen Gas. 



These experiments have been undertaken in the acade- 

 mical laboratory of the university of Kiel, (which is provided 

 with all the exact apparatus of modern chemistry,) for the 

 Biost part in common with my scholars, and particularly 

 uith one of them of the name of Dierks, wlio made himself 

 most frequently the subject of experiments. 



That I might determine with exactness the changes which 

 the atmospheric air undergoes by respiration, and be able 

 to decide the absorption of azotic gas, it was necessary to set 

 out, as from a solid foundation, with the diminution which 

 a determined volume of atmospheric air experiences by re- 

 spiration. It is therefore the first point to be determined by 

 exact experiments. 



1. There were respired 170 cubic inches of air (Paris mea- 

 sure) from one of the great reservoirs of a gasometer con- 

 structed at Paris (after the model of that of Charles, upon 

 water covered with oil, to hinder the absorption of carbonic 

 acid gas produced by respiration), once in the space of from 

 10 to 12 seconds. The diminution was 4-72 cubic inches, 

 = -^^ of the primitive volume. This experiment, repeated 

 twenty times in the same manner, aflbrded the same result. 



2. 144 cubic inches were respired in the space of from 

 10 to 12 seconds; the diminution was 4 inches, =z tJ-„- of 

 the whole volume. 



3. The same volume was respired twice during 23 seconds. 

 I he diminution amounted to 8 cubic inches^ = ^\ of the 



D 3 primitive 



