504 Dr. W. Marcet on the Function of Respiration at [Apr. 24, 



refers to the guide at Puerto, where his maximum is found to be 

 during the third hour after a meal. The fluctuations in my case may 

 be said to follow closely those formerly reported from my experiments 

 in the Alps. 



The subjoined table shows at a glance the variation of the mean 

 amount of carbonic acid expired during each successive hour after 

 food, the fifth or sixth hour being grouped together for want of a 

 sufficient number of experiments. 



Table showing the Influence of Food on the Expiration of Carbonic 

 Acid at the various Stations (in the sitting posture). 



Self sitting. 



Alta Vista. 

 Hours after Food. C0 2 expired per 

 minute. 



Gruajara. 

 CO-2 expired per 

 minute. 



Puerto. 

 C0 2 expired per 

 minute. 



2 „ 3 „ 



3 „ 4 „ 



4 „ 6 „ 



2 „ 3 „ 



3 „ 4 „ 



4 „ 5 „ 



0-534 (3) 

 0-502 (8) 

 0-472 (5) 



} 0-435 (4) | 



Gupelin sit 



| 0-604 (5) | 



0-570 (7) 

 0-525 (4) 

 No experiments 



0-374 (1) 

 0-497 (6) 

 0-486 (4) 

 0-424 (6) 

 0-398 (2) 



ting. 



0-560 (2) 

 0-609 (5) 

 0-560 (6) 

 0-565 (4) 

 0-489 (4) 



0-467 (3) 

 0-496 (5) 

 0-498 (6) 

 0-448 (4) 

 0-384 (2) 



~No experiments. 

 684 (5) 

 0-711 (6) 

 0-684 (5) 

 0-609 (2) 



The figures between brackets refer to the number of experiments. One experi- 

 ment, at 5.48 a.m. at Gruajara, not included. 



If the figures reported in this table be taken into consideration 

 together with the corresponding results obtained in the Alps, it will 

 appear that the maximum amount of carbonic acid is expired rather 

 earlier after a meal on the mountains than in the plains, which would 

 show that there is apparently a tendency to a more rapid digestion 

 and assimilation of food in the mountains than near the sea level. 



As in the case of my former investigation, I have neutralised as 

 much as possible the influence of food on the results of the experi- 

 ments, by conducting the inquiry at all times of the day between 

 breakfast and bedtime. 



Influence of Temperature on the Carbonic Acid expired. — So far, to my 

 knowledge, the only series of observations we possess on the influence 

 of tropical climates on the functions of the human body, are those of 

 Dr. Rattray, Surgeon R.N., who has clearly taken great pains to 

 investigate the subject ; he concludes that : — 



" The three marked tropical phenomena, viz., diminished lung 



