Death in Closed Vessels 537 



air, and again filled up with oxygen. After three or four such 

 manipulations, the bell-jar was full of a mixture sufficiently oxy- 

 genated for the purposes of the experiment, that is, causing the 

 bird to die under the diminution of pressure deemed desirable. 

 I then took a certain quantity of the mixture for analysis. 



I shall now give the details of the experiments; I shall discuss 

 here only those made at very low pressures. We shall see, in the 

 chapter dealing with death from carbonic acid, that this element 

 complicates the question for normal pressure and for moderate 

 decompressions when super-oxygenated air is used. I shall elimi- 

 nate it here; besides, the proof we seek will be all the clearer, the 

 lower the pressures fall. 



Experiment XLVII. January 29. Bell- jar of 1.9 liters. 



Mountain sparrow. Pressure lowered 50 cm., sick, oxygen admit- 

 ted; lowered 60 cm., hardly affected, oxygen admitted; lowered 66.5 

 cm., quite sick, oxygen admitted to 40 cm., pressure lowered 52 cm. 



Cocks closed at 3:15; after sample of air is taken, the decompres- 

 sion is 54 cm., at 3:45, in good condition; at 5 o'clock, panting; the 

 actual pressure is 19 cm. Dies at 6:30, without a motion. 



Actual pressure, 18 cm. Original mixture, O-' 85.9. 



Lethal air: CO, 68.1; O2 15.4. 



18 



CO; tension = 68.1 x = 15.2. 



76 



18 



Oxygen tension = 15.4 x = 3.6. 



76 



Experiment XLVIII. April 23. Bell-jar of 1.5 liters. 



Pressure lowered successively 54 cm., 57 cm., 62 cm., 67 cm.; each 

 time oxygen admitted, then air admitted until the decompression 

 equalled 61.5 cm. Cocks closed at 4:12. Found dead at 6:15. Thin layer 

 of bloody suffusion in the cranial diploe. Pressure is 14 cm. 



Lethal air: CO* 48.0; O2 23.8. 



CO2 tension = 8.8. Oxygen tension = 4.3. 



Experiment XLIX. February 6. Bell-jar of 1.9 liters. 



Pressure lowered 30 cm., 50 cm., 50 cm., with successive admis- 

 sions of oxygen; then to 14 cm. Entered at 2:20; very restless; dead at 

 4:45. Bloody suffusion. 



Actual pressure 12.5 cm. Original mixture O2 88.4. 



Lethal air: CO* 66.0; O2 22.2. 



CO2 tension = 10.8. Oxygen tension = 3.6. 



Experiment L. January 29. Bell-jar of 2.30 liters. 



Pressure lowered 48 cm., 52 cm., 64.5 cm., following successive ad- 

 missions of oxygen; cocks closed at 2:40. 



At 2:50, sample of air taken, which lowered the actual pressure 

 to 10 cm. At 3:30, still moving; at 4:45, dead. 



