THE COMPOSITION OF EXPIEED AIR AND ITS EFFECTS 

 UPON ANIMAL LIFE. 1 



ABSTRACT OF A REPORT ON THE RESULTS OF AN INVESTIGATION MADE FOR 

 THE SMITHSONIAN INSTITUTION UNDER THE PROVISIONS OF THE HODGTCTNS 

 FUND. 



By J. S. Billings, M. D., S. Weik Mitchell, M. 1)., and 

 D. H. Bergey, M. I). 



In May, 1893, a grant was made from the Hodgkins fund to Drs. 

 John S. Billings and S. Weir Mitchell "for the purpose of conducting 

 an investigation into the nature of the peculiar substances of organic 

 origin contained in the air expired by human beings, with special ref- 

 erence to the practical application of the results obtained to problems 

 of ventilation for inhabited rooms." 



For a number of years prior to 1888 the prevailing view among phy- 

 sicians and sanitarians had been that the discomfort and dangers to 

 health and life which had been known to exist, sometimes, at least, in 

 unventilated rooms occupied by a number of human beings, were 

 largely or entirely due to peculiar organic matter contained in the air 

 expired by these persons, and that the increase in carbonic acid due to 

 respiration had but little effect in producing these results, its chief 

 importance being that it furnished a convenient means of determining 

 the amount of vitiation of the air. Becently, however, several experi- 

 menters have concluded that the organic matters in the exhaled breath 

 are not harmful, at all events to animals, and the main object of the 

 proposed investigation was to determine the correctness of these 

 conclusions. 



The effects produced on animals and men by an atmosphere contami- 

 nated with their exhalations, and with particulate matters derived from 

 their bodies or their immediate surroundings, may be divided into acute 

 and chronic. The acute effect may be death in a few minutes or hours, 

 as shown by the results observed in the Black Hole of Calcutta, in the 

 steamer Londonderry ', and in many of the experiments referred to in 

 this report, or it may be simply great discomfort, especially in those 

 unaccustomed to such conditions. 



'The full report is printed in Smithsonian Contributions to Knowledge, Vol. XXIX 

 (No. 980), 4to, pp. 81. 



389 



