THE DISSOCIATION OF OXY-HASMOGLOBIN A't HIGH ALTITUDES, 261 
The investigation was undertaken for the purpose of controlling 
the results of similar climbs at high altitudes. The comparison is 
as follows :— 
1. Altitude up to 15,000 feet produces a lowering in the carbonic 
acid pressure, nevertheless the blood remains mesectic in the resting 
subject. 
For instance, at the Capanna Margherita? on Monte Rosa the day 
after arrival Roberts’ alveolar carbonic acid pressure was 26 mm. 
The following points determined at these pressures fall on his mesectic 
curve (see previous paper). 
Percentage saturation . 33 77 calculated from mesectic curve 
Percentage saturation . 34 73 (observed) 
Oxygen pressure. . . 19 4] 
2. A given degree of meionexy is produced by a lesser degree of 
activity at high altitudes. Thus at Col d’Olen, climbing 1,000 feet, 
from an altitude of 9,000 feet to 10,000 in 38 minutes, Roberts’ 
curve became as follows :— 
n=2'5, K="000161, log K=4:2068, CO,=36 mm. 
The degree of meionexy is almost identical with that produced at 
Carlingford when climbing the same height in 20 minutes. 
3. A greater degree of meionexy is produced by a given amount 
of exercise at high altitudes. Thus Barcroft, climbing from 9,000 
feet to 10,000 feet in 45 minutes at Col d’Olen, moved the constants 
of his curve as follows :— 
Mesectic curve . = 2°5, K = -000292, log K = 4°4654 
Meionectic curve n= 2°5, K=-000191, log K = 4:2810, CO, = 33mm. 
Corresponding points would be 
Percentage saturation 9 20 34 48 58 84 94 mesectic 
Percentage saturation 6 14 26 37 48 77 92 meionectic 
Oxygen pressure - 10 15 20 25 30 50 
Climbing from sea level to 1,000 feet at Carlingford also in 45 
minutes no certain degree of meionexy could be ascertained. The 
following points were observed :— 
CO, pressure 38 mm. 
Percentage saturation 58 calculated from mesectic curve. 
Percentage saturation 56 per cent.—55 per cent. observed. 
Oxygen pressure 30 mm. 
The Effect of Low Temperatures on Cold-blooded Animals.— 
Report of the Committee, consisting of Professor SWALE 
VINCENT (Chairman) and Mr. A. T. CAMERON (Secretary). 
(Drawn up by the Secretary.) 
Messrs. Cameron AND BrowNizE have carried out a number of 
experiments on frogs (R. pipiens) obtained from the neighbourhood 
2 For the amounts of acid added see Brit. Assoc. Report, 1911, p. 153. 
