FROM THE AIR BY RESPIRATION? 913 



of nitrogen was permanently absorbed during 

 respiration, after which, similar results were 

 obtained by Henderson and PfafF. 



These general results have been confirmed by 

 the experiments of Macaire and Marcet, Mi- 

 chaelis, Magnus, Dr. Clanny, Mulder, and others, 

 who have found that there is more nitrogen in ar- 

 terial than in* venous blood, which could not be 

 the case if it were not absorbed from the atmos- 

 phere. Yet we are told, that in a majority of the 

 experiments performed by Dulong, Despretz, 

 and Nysten, more nitrogen was exhaled during 

 the respiration of warm blooded animals than was 

 absorbed. What is still more incredible, (because 

 contradicted by innumerable experiments of many 

 of the most distinguished chemists in Europe,) it 

 is stated by Liebig on the authority of Despretz, 

 that more nitrogen is exhaled from the lungs of 

 herbivora than of carnivora. But if the German 

 Professor had examined these results with the 

 same attention which he bestowed on Despretz's 

 theory of animal heat, he would have found them 

 equally fallacious. 



Some highly important experiments performed 

 by Dr. W. F. Edwards, enable us in some mea- 

 sure to comprehend the contradictory results of 

 different chemists, and even those of the same 

 individuals at different times, or under different 

 circumstances. For example, he found that more 

 nitrogen was exhaled by new born guinea pigs 



