856 Experiments 



very rapidly without inconvenience to a pressure of 7 cm., if the air 

 has a high oxygen content. 



Let us now examine the results of a few experiments made 

 especially with a view to sudden decompression: 



Experiment CCCCXCVIII. March 2. Dog weighing 2.300 kilos, 

 placed in a bell of 31 liters capacity. This bell (Fig. 27, C) is con- 

 nected by a rubber tube with thick walls to a huge receiver of sheet- 

 iron (B) in which the pressure has been brought to a 10 cm. A commu- 

 nication cock is opened, and the pressure falls immediately in the bell 

 to 12 cm. Immediately convulsive struggling, howls, foamy nasal hem- 

 orrhage; dead in 3 or 4 minutes. The lungs display ecchymoses which 

 do not disappear entirely after insufflation. Bronchi and trachea full 

 of bloody foam. Dark blood in the left cavities of the heart, very 

 dark blood on the right, without free gases. 



Experiment CCCCXCIX. March 7. Large cat. Same experimental 

 procedure. Pressure is brought suddenly to 16 cm.; the animal rears up 

 almost immediately, struggles violently, yawns. At the end of 2 min- 

 utes, falls on its side, its tongue is dark; at 3 minutes, its pupils dilate, 

 shivers occur in the cutaneous muscles. Dead after 6 minutes. With- 

 drawn immediately, the animal, which is much swollen, collapses 

 when normal pressure is restored; no gas in the blood; dark blood 

 in the left heart, still more in the right heart; pulmonary veins red; 

 pulmonary ecchymoses. 



Experiment D. March 15. Sparrow placed immediately by a sim- 

 ilar arrangement at 12 cm. pressure. 



Struggling; very speedy death without true convulsions. No free 

 gases in the blood. 



Experiment DI. June 18. Cat brought very rapidly to a pressure of 

 12 cm. Dies after a very rapid phase of convulsions. Lungs congested, 

 expand and become blanched when insufflated; the most congested 

 parts do not sink in water. No gas in the blood, examined with great 

 care. 



Experiment DII. December 16. Two rats, placed in a bell of 2 

 liters, are brought as rapidly as possible (2 or 3 minutes) to a pres- 

 sure of 4.5 cm. They whirl, leap, die without true convulsions. With- 

 drawn immediately, and opened, one, A, in the air, the other, B, under 

 water: the hearts are still beating. 



A. Blood examined by a magnifying-glass in the vessels ,then with 

 a microscope; no gas bubbles. Lungs very red in places, the red pieces 

 sink in water; they expand with insufflation. 



B. No bubbles of gas can be seen escaping under water. 



Experiment Dili. December 16. Rat killed by the same process, at 

 the same pressure; but kept for 10 minutes at 4.5 cm. No gas in the 

 blood, meticulous examination. Lungs adherent to the thorax, but 

 regain normal position when it is opened; reddish with small dots, all 

 parts float. The liver macerated with charcoal shows an enormous 

 quantity of sugar. 



