302 



Dr. W. Marcet on 



[Apr. 11, 



Station. 



Yvoire 



St. Bernard <{• 



St. Theodule 

 Breithorn . . 



Occupation. 



Walking level 



Walking level 



Walking up rapidly 

 over rocks and grass 

 patches 



Walking up leisurely 



Walking level 



Ascending rapidly 

 steep slope 



Walking level 



Weight 

 of C0 2 

 expired 



per 

 minute. 



Grrrns. 

 2-249 

 2-457 



3156 

 2-120 



1- 919 



2- 972 

 1-886 



"Volume 

 of air 

 expired 



per 

 minute. 



Litres. 

 25-84 

 24-77 



32-45 

 19-72 

 22-06 



24-97 

 19-48 



Relation of 

 C0 2 toC0 2 



expired 

 sitting at 



station. 



5-42 to 1 

 5-35 to 1 



6-86 to 1 

 4-82 to 1 

 4-32 to 1 



6-69 to 1 

 3-87 to 1 



Per 



cent. 



C0 2 

 in air 



ex- 

 pired. 



4-4 

 50 



4- 9 



5- 4 

 4-4 



6- 1* 

 50 



The results have been disposed in a tabular form, and appear to 

 show that while walking on level ground, when a certain altitude is 

 reached, there is a decided fall in the amount of both the carbonic acid 

 and air expired. Yvoire and the St. Bernard gave nearly the same 

 results; but when the height of the St. Theodule Pass was a/ttained 

 (10,899 feet), there was a reduction in the expiration of carbonic acid 

 while walking on level ground from 2*249 grms. at Yvoire, and 2*457 

 at the St. Bernard, to 1*919 grms. ; on the summit of the Breithorn 

 there was a further fall of carbonic acid expired to 1*886 grms., while 

 the volume of air expired per minute was reduced from 24*77 litres 

 to 19*3 litres ; but the experiments are not numerous enough to allow 

 of any but very general results. The same remark applies to the 

 experiments made walking up hill. They certainly show, however, 

 that walking up rapidly over rocks and grass patches at or below the 

 elevation of the St. Bernard, yield most carbonic acid, the amount 

 being as much as 3*156 grms. per minute at the St. Bernard, which 

 was attended with the inhalation of the largest volume of air breathed. 

 Ascending quickly at the height of St. Theodule caused a considerable 

 elimination of carbonic acid through the lungs, amounting to 2*972 

 grms. On the other hand, walking leisurely up hill at the St. Bernard 

 gave rise to the production of no more carbonic acid than quick walk- 

 ing on the level ground at that same station ; indeed, the amount was 

 a trifle less. 



These experiments, therefore, give an idea of the extreme quantities 

 of carbonic acid expired at various altitudes under moderate and great 

 muscular exertion, and appear to show that at great elevations, such 

 as that of the summit of the Breithorn, and perhaps lower, the body is 

 less able to take in a sufficient amount of air for the supply of carbonic 



* Appears rather high. 



