684 Experiments 



greatest drops in temperature. One of them (Exp. CCXXIX) , kept 

 for an hour at a pressure of 35 cm., and for an hour more at 25 and 

 even 22 cm., had a rectal temperature of only 25°, on leaving the 

 bell. But after a few minutes the temperature rose to 31° and the 

 animal survived. The, guinea pig of Experiment CCXXVII, whose 

 respirations furnished the graph in Figure 48, which remained 

 nearly four hours oscillating between 21 and 11 cm., had a tempera- 

 ture of only 20°; it is true that he died during the night after the 

 experiment. 



Decompression then is in itself a cause of a drop in body tem- 

 perature. In balloon ascensions, this cause is added to the direct 

 action of an extremely low environmental temperature. In moun- 

 tain journeys, these two causes take on a more serious importance 

 because of the expenditure of energy required by the ascent. It is 

 within these limits that the idea of Lortet can a priori be exact; 

 but the decompression certainly must hinder the internal oxidation 

 from acting as it would at normal pressure; no one will ever have 

 mountain sickness from climbing a hill 1000 meters high, even if 

 he were loaded with the heaviest burdens. 



5. Development. I think I should report here an experiment 

 which shows that the development of chrysalises is considerably 

 impeded by lowering the pressure. 



Experiment CCXLVII. June 23. Silkworm cocoons, within a day 

 of the same age, sent from Alais by M. Raulin, are placed: 



A. 12 in a bell open above, and consequently at normal pressure; 



B. 18 in a bell of 3.2 liters, at a pressure of 50 cm.; 



C. 18 in a bell of 7 liters; pressure of 38 cm.; 



D. 18 in a bell of 13 liters; pressure of 25 cm.; 



E. 5 in a bell of 6 liters; pressure of 5 cm. 



Bell D is broken June 25; the water of the hydraulic seal enters 

 with the air; it is left unchanged. Every other day the air is changed 

 in bells B and C; every day that in bell E is changed. 



July 8, the experiment is stopped, everything is thrown open to 

 the air, and the cocoons are opened. 



The cocoons of A and D have been open since morning; the moths 

 have issued. 



Of the chrysalises in B, 3 are metamorphosed, but the moths have 

 remained in the cocoon. 



The others show considerable signs of life but are not metamor- 

 phosed. 



Those of C show some signs of life, but are not metamorphosed. 



The cocoons of E are not opened. 



July 15, 3 more chrysalises in B are metamorphosed; but all are 

 dead. 



