202 x 



/ 



influence over the formation of this acid by the skin, 

 M. Jurine not only proved the greater consumption 

 *>f oxygen gas by the skin during a vigorous action 

 of the cutaneous organs, but likewise shewed, that 

 increase of temperature, muscular exertion, and di- 

 gestion,, had similar effects on the products of respi- 

 latioa. These experiments were followed out with 

 greater accuracy by MM. Lavoisier and Seguin, who 

 found, that a man at rest, with an empty stomach, 

 and in a temperature of 82, consumed in an hour 

 121O cubic inches of oxygen gas ; but that during 

 digestion, the consumption amounted to 18 or 190O 

 inches. With an empty stomach, and during vio- 

 lent exercise, 3200 inches were consumed in an 

 hour ; and when the same exertion was used after 

 taking food, the quantity was increased to 460O cu- 

 bic inches *. The difference in the results of these 

 experiments, is so very great, as to lead to a suspi- 

 cion, that some considerable error exists ; but, at all 

 events, they seem to prove, that whatever, in a cer- 

 tain degree, accelerates the circulation of the blood, 

 increases the consumption of oxygen gas in the 

 hrn'gs, and as this gas, in natural respiration, dis- 

 appears only in consequence of its union with car- 

 bon, it follows, that the carbonic matter must be 

 proportionally increased, which is a necessary conse- 

 quence of its being considered an animal excretion, 

 immediately dependent on the motion of the blood. 

 1\59. But, granting unto the several classes of ve- 

 getables and animals which have passed under our re- 



* Mem. de 1'Acacl. de Scien. 1789,^790. 



