LAVOISIER. 261 



Respiration (Mem. 1789) contains some very important 

 experiments which throw great light upon that process, and 

 some upon the production of animal heat. They not 

 only clearly shew that the oxygenation of the blood, in 

 passing through the lungs, produces both carbonic acid 

 gas by the slow combustion of carbon, and water by 

 that of hydrogen, the carbon and the hydrogen being- 

 alike supplied by the blood, which as early as 1785 

 M. Lavoisier had suspected from many appearances;'" 

 but they enable us to ascertain the exact quantity of 

 oxygen gas consumed, and of carbon and hydrogen in- 

 haled in the process ; for they shew 24 cubic feet of gas, 

 or 2 Ibs. 1 oz. and 1 scruple to be consumed in 24 hours, 

 and 2 Ibs. 5 oz. and 4 scruples of carbonic acid to be 

 formed with 5 scruples 51 gr. of water: answering to 

 10 oz. 4 scruples of carbon and 1 oz. 5 scruples and 

 51 gr. of hydrogen. A number of valuable physiological 

 and therapeutical conclusions are derived from the same 

 inquiry. In the paper on Transpiration (Mem. 1 790) the 

 inquiry is continued, and a general estimate is formed 

 by approximation of the amount lost in the 24 hours by 

 this process; it is 1 Ib. 14 oz. and only 5 drachms by res- 

 piration : a calculation not reconcileable with the former 

 course of experiments, which made the loss under 12 oz. 

 Beside these Memoirs, and one or two others of less 

 importance on chemical subjects, he gave a paper in 

 1789 upon the horizontal strata deposited by the sea; 

 a subject to which he had, in the earliest period of his 



* The theory of the present day departs somewhat from Lavoi- 

 sier's, particularly in holding that the carbonic acid is not produced 

 at the surface of the lungs, and that the oxygen- enters into combi- 

 nation with the mass of the blood, forming water and carbonic acid 

 at the capillary terminations of the vessels. 



