AND INSENSIBLE PERSPIRATION. 315 



parts of a lb. troy of carbone = .642 parts of 

 a lb. avoirdupoise = lOJ ounces, nearly. Now 

 when I estimated the quantities of carbone in the 

 several articles of food, &c. just related, I had 

 no recollection of this quantity of carbone ex- 

 pended in breathing ; it may well be supposed 

 then, that I was highly gratified to find by the 

 calculation that the difference of the two quan- 

 tities, found by such different modes of investi- 

 gation, was only one quarter of an ounce. 



With respect to the aqueous vapour exhaled 

 from the lungs I have determined in the essay 

 quoted above, (page 29) that the highest esti- 

 mate of the quantity I exhale cannot exceed 

 1.661bs troy = 1.275lbs. avoir. = 20i ounces 

 avoir. ; if to this we add lOJ ounces of carbone, 

 we have 30J ounces for the carbone and water 

 expended from the lungs in one day, and this 

 taken from 37i leaves 6| ounces per day, for 

 the insensible perspiration from the skin, which, 

 if the above estimate be allowed, must consist 

 of 6 J ounces water, and one quarter of an ounce 

 carbone. According to this, the matter perspired 

 from the lungs is five times as much as that 

 from the whole surface of the body. 



If, instead of carbone, we trace the element 

 azote into and out of the body we shall find 

 2r2 



