SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE. 



- ttS'J 



IDofcghins jfunb. 



THE 



Composition of expired Air 



AND ITS 

 EFFECTS UPON ANIMAL LIFE. 



BY 



J. S. BILLINGS, M.D.. S. WEIR MITCHELL, M.D. 

 AND D. H. BERGEY, M.D. 



CITY OF WASHINGTON : 

 PUBLISHED BY THE SMITHSONIAN INSTITUTION. 



1895. 



^ 





