On the Rcspirailon of Almm[)hvric Air. 5.} 



during a space of from ,10 to 12 seconds; and the iniclJ'e 

 quantity of the expired air was received o\er luercury. lu 

 this respired air the constituent parts in a liundred were 4* 10 

 of carbonic acid gas ; lG'55 of oxygen gas absorbed by slow 

 combustion of phosphorus; and 7 9" 19 of azotic gas. Au 

 eiidiometrical experiment, made at '.he same time, gave the 

 following proportion in the atmospheric air: 1 carbonic 

 acid, 21 oxvgen gas, 78 azotic gas. The total diminution 

 of the air was, according to the preceding exjieriments (l.) 

 ;= -jij-. We find, therefore, the true quantity of azotic gas 

 by the following proportion: 36 : 35 = 79" 19 ; a- = 7t3-9y. 



By subtracting these 76'9<) from 78, the primitive quan- 

 tity of azotic gas, we have a deficiency of roi ; the volume 

 of air before respiration being supposed to be divided into 100 

 parts. As the quantity of air inspired was = 80 cubic 

 inches, the absolute diminution of azotic gas by a single 

 respiration is found by this proportion, 100 : SO = roi : .f 

 = 0*808 cubic inch. 



9. \\\ another experiment €>0 cubic inches were respired 

 once in the space of from lo to 12 seconds, and the latter 

 portion of expired air was received over niercurv. The pro- 

 portion of constituent parts in 100 were, 4'68 of carbonic 

 acid gas, l7-()8 of oxygen gas, 7 7*74 of azotic gas. An 

 eudiometrical experiment made at the same time, gave, in 

 100 parts, 1 carbonic acid, 22 oxygen gas, 77 azotic gas. 

 To find the true quantity of azotic gas it is necessary to di- 

 jninish the 77*74 of azotic gas by -}^, which gives, by pro- 

 portion, 36:35 = 77'74:.r. This cju-uuiiv = 75-58, sub- 

 tracting the quantity of azotic gas beU)re respiration, leaves 

 a loss of 1*42, supposing the volume of air to be divided 

 into 100 part*. The true diminution is therefore found by 

 t^ie following proportion, 100 : Oo -^ J*42 : x = 0*852 

 cubic inch. 



JO. Thirty cubic inches werg respired, in the same man- 

 ncTj three times daring l(j seconds. The air which was ex- 

 spired contained, in 100 parts, 5 of carbonic acid gas, H-.Ti 

 pf oxygen gas, 80*5 of azotic gas, The atmospheric air 

 contained, according to an eudiometrical experiment iuadg 

 ^t the same time, 1 of carbonic acid gas, 20*975 of oxygen 

 D 1 «>:as. 



