Manchester Memoirs, Vol. hii. (191 3), No. 14. 



XIV. The Influence of Moisture in the Air on 

 Metabolism in the Body. 



By William Thomson, F.R.S.E., F.I.C., F.C.S. 



( Read April Sth, igrj. Received for pnhlication April 22iid, rgjj.) 



In a previous paper read by me before this Society 

 (2ist of March, 1911), I endeavoured to shew that the 

 changes in the degree or amount of metabolism going on 

 in the body depend largely on alterations in the state of 

 the atmosphere, such as those of temperature, pressure, 

 and humidity — the lowering of the temperature, or of the 

 pressure, or of the percentage of humidity of the air 

 producing increased metabolism, as measured by the 

 percentage of carbon dioxide (carbonic acid gas) in the 

 exhaled air from the lungs, whilst the raising of the 

 pressure, or of the temperature, or of the percentage of 

 humidity reducing the percentage of carbon dioxide 

 (COo) in the exhaled air. All these atmospheric con- 

 ditions are continuously and simultaneously altering, and 

 the net results as regards metabolism may thus be deduced 

 (within limits) from the nature and amounts of such 

 changes. After writing this paper my attention was 

 drawn to the very able memoir by Drs. J. S. Haldane and 

 J. G. Priestly (Vol. XXXII., 1905, of The Journal of 

 Physiology),v]\i\c)\ I read with much interest. Dr. Haldane 

 expressed to me some doubt as to whether the degree of 

 humidity would materially affect the percentage of COo 

 in the exhaled air, and in deference to his opinion as the 

 highest authority in these matters I determined before 

 submitting my previous paper for publication to further 



October jrst, IQIJ. 



