1879.] Various Altitudes on the Island and Peak of Teneriffe. 517 



Island of Teneriffe is greater than it had been in the Alps, and, more- 

 over, this same result holds good for corresponding altitudes. The 

 mean excess for all the experiments on Teneriffe in the sitting 

 posture, amounts for myself to 14*0 per cent. It was at the seaside 

 that the increase in my case reached the maximum, 18*7, when com- 

 pared with the weight of carbonic acid expired near the Lake of 

 Geneva, I have only four experiments to place on record made on 

 the guide in the Alps (St. Bernard) ; these compared with the means 

 of the experiments to which he subjected himself at the seaside, 

 Teneriffe, gave for the latter station an increased expiration of car- 

 bonic acid by 17 '5 per cent. There was, however, no increase for the 

 higher stations at Teneriffe. 



5. While, in the Alps, the maximum quantity of carbonic acid was 

 expired by myself at the highest station, 13,685 feet above the sea, 

 where the body underwent the greatest degree of cooling, especially 

 from the low temperature of the air ; on the Peak of Teneriffe, the 

 weight of carbonic acid I expired at the various stations differed but 

 little. 



6. The weight of carbonic acid expired in a given time by myself 

 on the Peak of Teneriffe varies but little from one station to another, 

 although I show a tendency to give out slightly more of this gas at the 

 two highest stations — mean altitude 11,222 feet — than at either 7,090 

 feet high, or the seaside. The increase for the mean of the two 

 highest stations above the amount expired at the seaside is only 1*2 

 per cent. In the Alps, the excess of carbonic acid I expired at 

 13,685 feet, over the amount given out near the Lake of Geneva at 



I, 230 feet, or for a difference of altitude of 12,455 feet, amounted to 

 15 per cent. This result is accounted for from the temperature of 

 the air, which was much colder in the Alps than on the Peak of 

 Teneriffe. 



In the case of the guide, a great deal more carbonic acid was 

 expired at the seaside on the Island of Teneriffe than on the Peak, 

 the excess amounting to 17 per cent. ; while I expired about as much 

 carbonic acid at every altitude on that Island. This occurred appar- 

 ently because the guide perspired more than I did at the higher 

 stations ; moreover, I am accustomed to live at the sea level, while 

 the guide had never been away from the Alps, and his life, in summer, 

 is spent, in a great measure, accompanying tourists to the highest 

 peaks and passes in the Alps ; his home at Chamounix is 3,451 feet 

 above the sea. 



7. The volume of air I expired per minute reduced to 32° P. and 

 seaside pressure decreased gradually from the seaside to an altitude of 



II, 745 feet, the difference for the two extreme stations amounting to 

 14' 6 per cent. This result agrees to some extent with that obtained 

 in the Alps, although the Alpine decrease amounted only to 5*6 per 



