00 OF RKSI'IRATION. 



aqueous vapour, which is condensed in a visible lorn* 

 by a temperature of (J0° of Fahr.* 



150. It is therefore probable, that, daring inspira- 

 tion, the base of the oxygenous portion is set at liberty, 

 and, being united with the arterial blood, is conveyed 

 throughout the system ; while the carbon and hydrogen 

 are brought back with the venous blood to the right 

 side of the heart, and thrown off like smoke, as the 

 ancients expressed it, in the lungs. + 



The more florid colour of the arterial blood, | the 

 darker of the venous, and the analogous appearance of 

 the blood, if exposed to the gases in question, (13) 

 correspond admirably with this theory. Some diffi- 

 culties, indeed, remain to be solved, v. c. how the 

 carbon can be united in the lungs with the oxygen, so 

 as to fly off in the form of carbonic acid gas. (C)§ 



151. This perpetual change of elements occurring in 



For the third, I employed the carbonised air expired by the second dog. 

 He died in four minutes. 



The air of the bladder, upon subsequent examination, gave the common signs 

 of carbonic acid gas. The instruments which I employed are described and 

 illustrated by a plate in the Medic. Biblioth. Vol. 1. p. 174 sq. tab. 1. 



• J. A. De Luc, Ide'es sur la Mitiorologie. torn. ii. p. 6". 229. 



t Rob. Menzies, De Retpiratione. Edinb. 1790. 8vo. 



H. G. Ronppe on the same subject. Lugd. Ratav. 1791. 4to. 



J. Bostock, Versuch uber da* Athrmolen. hben. von A. P. Nolde. Erf. 

 1809. 8ro. 



J J. Andr. Schcrcr, Beweit dim J. Mayow ror 100 Jahren din Grumd zur 

 antiphlogiituchen Chemie und Physiologic gelegt hat. p. 104. Edm. Goriwvn, 

 Connexion of Life with Respiration. Load. 1788. 8vo. J. Hunter, On the 

 Blood, p. 68. J. A. Albers, BeytrSgen sur Anmt. und Phytiol. der Thieve. 

 P. 1. p. 108. 



§ Sec J. Brugnatelli, Elementi di Chimica. T. 1. p. 155. J. Fr. Gmelin, 

 De Acidorutn origint ex aire vitali adhuc dubia in the Comment. Soc. Beg. Sc. 

 Cotting. T. xiH. 



