1881.] On the Influence of Altitude upon Respiration. 431 



than in M. David's. His increase was by 39*5 per cent., and mine by 

 25 '6 per cent. I had occasion to remark, in a paper published last 

 year,* that my observations showed no increase in the frequency of 

 respiration in the Alps, while in the sitting posture, between the alti- 

 tudes of 1,230 feet (Lake of Geneva) and 8,115 (St. Bernard) ; but 

 between 8,115 feet and 13,685 feet (summit of the Breithorn) the 

 increase was in the following ratio : — To 8,428 feet, 20*4 per cent. ; from 

 thence to 10,899 feet, 12' 7 per cent, beyond the latter; from that ele- 

 vation to 13,685 feet, 6*3 per cent, more ; altogether 39 per cent. The 

 rate of breathing wa s not observed at that time quite in the same way 

 as on the present occasion, as it was then reckoned while expiring into 

 the bag, and not into the open air. I cannot anticipate, however, 

 any actual difference in the results, as- there is no reason why the rate 

 of expiration into the bag should not be proportional at various alti- 

 tudes to the rate of expiration into* the open air at these same 

 altitudes respectively. 



I feel called upon to remark that the figures for the carbonic acid I 

 expired in the experiments which form the subject of the present paper 

 are higher than those reported in my earlier experiments, while the 

 volume of air expired is rather largely increased in this last inquiry, 

 which I am hardly prepared at present to account for. A series 

 of experiments made on myself at Yvoire in autumn, 1879, yielded 

 weights of carbonic acid much nearer to those last obtained. The 

 weight of air expired for one gramme of carbonic acid, which had 

 been somewhat smaller in the earlier experiments, rose in those of 

 1879 at Yvoire to a figure but slightly inferior to that obtained in the 

 experiments of 1880. 



* " On the Biviera, Madeira, the Canary Islands, and Davos, with reference to 

 their Climate for Consumptive Invalids." "Edin. Med. Journ.," 1880. 



