Death in Closed Vessels 551 



tions, we should find an average of about two minutes per kilogram 

 and per liter. Now, if we refer to the celebrated and classic work 

 of Regnault and Reiset on respiration, we shall find analogous 

 results, that is, the greater consumption of oxygen in a given time 

 by carnivores than by herbivores, by birds than by mammals, by 

 small animals than by large ones, etc. 



All the data which have just been given are summarized in 

 Table IV. 



I add, in conclusion, the account of an experiment (Exper. 

 LXXXII) made on a hedgehog July 6, with the purpose of trying 

 to put this animal into a state of hibernation by keeping it for a 

 certain time at very low pressure. But we could not, without 

 imminent danger, pass below a pressure of 18 cm.; at 26 cm., the 

 animal uncurled and vomited. After two hours, during which the 

 pressure varied between 28 cm. and 18 cm., we removed the ani- 

 mal, which recovered rapidly and survived. This hedgehog there- 

 fore behaved like a cat or any other animal not endowed with the 

 remarkable power of hibernation. 



C. Experiments on cold-blooded animals. 



I made only a few experiments on cold-blooded animals. Frogs, 

 so useful for other researches, often manifest a strange unevenness 

 in duration of life, composition of lethal air, etc., when they are 

 allowed to die in closed vessels, even at normal pressure. However, 

 here is a series of simultaneous experiments, in which, by taking 

 great precautions and choosing my subjects with great care, I suc- 

 ceeded in getting an interesting result: 



Experiments LXXXIII-LXXXVII, simultaneous. June 15, at 3 

 o'clock; temperature 22°. 



LXXXIII. Normal pressure, vessel of 275 cc; dies at 5 o'clock 

 in the evening, June 17. 



Lethal air: O 2.7. 



LXXXIV. Pressure of 20 cm.; vessel of 1.350 liters, representing 

 355 cc. at normal pressure; it dies June 16 at 2 o'clock. 



Lethal air: O- 8.4. Oxygen tension = 2.2. 



LXXXV. Pressure of 14 cm.; vessel of 1.9 liters, representing 

 350 cc. at normal pressure, dies June 16 at 2:50. 



Lethal air: O 15.3. Oxygen tension = 2.8. 



LXXXVI. Pressure of 10 cm.; vessel of 2.2 liters, representing 

 290 cc. at normal pressure; lived 4 hours. 



Lethal air: O? 18.5. Oxygen tension = 2.4. 



LXXXVII. Pressure of 5.5 cm.; vessel of 2.8 liters, representing 

 200 cc; lived 2 hours. 



Lethal air: Oa 18.6. Oxygen tension = 1.3. 



