Death in Closed Vessels 559 



30, and consequently would also be a branch of an equilateral 

 hyperbola. 



But we must note immediately that this formula begins to be 

 true only from IV2 and especially from 2 atmospheres. Below 

 that, the figures of Column 8 are much lower. In this case the 

 quantity of oxygen at the bird's disposal was not sufficient to per- 

 mit the production of a quantity of carbonic acid fatal in itself. 

 Of course the carbonic acid tension was not negligible, especially 

 when it reached the value of 22 or 23; but in this case we must 

 take into account the exhaustion of the oxygen, whose very ad- 

 vanced state is shown us by Column 9. In fact, we find here again 

 the figures varying from 3 to 4, which we recognize as expressing 

 the oxygen tension which is too low to support life. 



Influence of the temperature. The preceding results were ob- 

 tained at temperatures above 20°. I wished to find out whether 

 considerable cold would have much effect on the figures obtained. 

 Here is what occurred. 



Experiment CII. December 12; temperature of the laboratory 

 + 6°. House sparrow. Placed at a pressure of 6 atmospheres; closed 

 cocks at 2 o'clock. Surrounded the apparatus completely with a mass 

 of snow at 0°. 



At 4:20, sparrow found dead. At 4:25, his rectal temperature was 

 + 4°. 

 Lethal air: CO.- 2.9; O* 17.4. 



CO. x P = 17.4. 



Experiment CHI. December 13; temperature +6°. House sparrow. 

 At 2 o'clock, placed at 5 atmospheres. Surrounded the apparatus with 

 a mixture of ice and salt whose temperature dropped to 2°. The inside 

 thermometer could not be read. At 3:35, found dead. Rectal tempera- 

 ture, +8°; venous blood red, without gas bubbles. 



Lethal air: CO. 3.4; O. 15.2. 



CO. x P = 17.0. 



Experiment CIV. December 14; outside temperature +5°. House 

 sparrow. At 2:50, taken to 4 atmospheres. Surrounded by a mixture 

 of ice and salt. 



At 4:20, very sick; at 4:30, dead. Inside temperature of apparatus 

 +1°; rectal temperature, -\-11.5°. 



Lethal air: CO. 5.0; O. 13.3. 



CO, X P = 20. 



We see that the effect of the cold was very important, and that 

 the birds could not in these conditions form as much carbonic acid 

 as at high temperatures. That is easily understood, because of 

 the chilling of the animal, which was not compatible with the 



