Compressed Air; O. Poisoning 745 



of carbonic acid given off by the same animal placed successively 

 in a closed vessel, in ordinary air or in a superoxygenated air at the 

 same degree of compression. The special action of the carbonic acid 

 is thus eliminated, because it is obviously the same in both cases. 

 Here are the details of an experiment conducted in this way. 



Experiment CCCIV. Albino rat. Rectal temperature 38°. May 10. 

 Placed from 4:05 to 6:35 (2 hours 30 minutes) in the large receiver 

 made of a mercury bottle (containing 3 liters), under a pressure of 

 3V4 atmospheres of air. When he is taken out, his temperature has 

 fallen to 30°; he is quite sick, breathes slowly and deeply, but recovers 

 quite quickly. 



The air of the flask contains 12.5% of oxygen, and 6.6% of car- 

 bonic acid. 



May 12. The animal has recovered perfectly; we begin again the 

 same experiment, as to pressure and length; but this time we use air 

 containing about 60% of oxygen. The tension of this gas corresponds 

 then to that of compressed air from 9 to 10 atmospheres. 



At decompression, the animal is found very low, not sensitive to 

 pinching, but sensitive in the cornea. His rectal temperature is only 

 23.8°. He does not move, and dies at the end of a half-hour; no gas 

 in the blood vessels. 



The air in the receiver contained only 5.3% of carbonic acid. 



Experiment CCCV. July 1. A. Two sparrows weighing together 

 38 gm. are subjected to a pressure of 5 atmospheres of air for 32 

 minutes, in the Seltzer water receiver. 



Taken out after sudden decompression, seem very well, with 

 slight bloody suffusions on the cranium. 



During this time they consumed 3.9% of oxygen, and produced 

 2.8% of carbonic acid. 



B. Two other sparrows, weighing together 39 gm., are placed next 

 in the same apparatus, at the same pressure, but in air containing 

 72.6% of oxygen; the tension, 5 x 72.6 = 363.0, corresponds to about 

 that of 18 atmospheres of air. They remain in the apparatus for 27 

 minutes. 



At the end of 5 minutes there occurred in the two birds convul- 

 sions which lasted with intensity for 15 minutes. Then the sparrows 

 remain lying on their backs, panting heavily. 



One of them dies at the end of an hour; the other, after seeming 

 to recover, but keeping up incessant muscular quiverings, is seized 

 with convulsions after an hour and a half, and dies in a half hour. 



Both immediately take on rigor mortis; moderate bloody suffu- 

 sions. 



In 27 minutes they consumed 2.05% of oxygen, 1.07 in the 'first 

 17 minutes and only 0.35 in the last 10; they produced in the first 17 

 minutes 1.07% of carbonic acid, and 0.28 in the rest of the time, in 

 all 1.35. 



We see from these figures that in 10 minutes at 3 atmospheres of 

 air 1.2% of oxygen was consumed and 0.8% of carbonic acid was 



