Symptoms of Decompression 687 



Pressure Hawk Gull Sparrows 



38.8 cm B, D vomit 



34.8 cm Vomits B, D vomit 



31.8 cm Staggers, vomits B, D vomit 



29.8 cm Staggers, vomits A vomits 



27.8 cm. Vomits Staggers, vomits C vomits; D very- 

 sick. 

 20.3 cm. Lying down, very sick. Lying down, sicker 



than the hawk. A and D dying. 

 18.8 cm. Lying down, very sick. Dying; cock opened Cock opened 

 17.8 cm. Dying; cock opened. 



And so the hawk is hardly more than a centimeter ahead of the 

 gull, and two or three ahead of the sparrows. It would be very 

 interesting to run an experiment not merely on a zoological repre- 

 sentative of the high-flying birds of prey, but on one of these 

 birds itself, a condor, for example; unfortunately, physiologists are 

 not likely to have such luck. 



Among the mammals, cats seem almost as susceptible as spar- 

 rows. They are certainly more so than dogs, for whose death the 

 pressure must be lowered to 10 or 8 centimeters. Furthermore we 

 have seen in the historical part that cats are hard to raise at high 

 altitudes and even die soon there. 



Guinea pigs and rabbits are very easy to bring to low pressures, 

 and since their temperature drops very quickly, they reach the 

 state of cold-blooded animals, so to speak. 



New-born kittens are nearly in this state; and so they die a little 

 later than adults. 



I had hoped, by subjecting to decompression an animal which 

 hibernated, to bring it to very low pressures also, thinking that it 

 would hibernate, so to speak; but the only experiment which I 

 tried, on a hedgehog, disappointed me. I could not go below 18 

 centimeters without the life of the animal seeming immediately in 

 danger. 



Finally I add that, as might have been expected, cold-blooded 

 animals resist extremely low pressures. 



7. Death. 



I have shown above that sometimes the animal dies without any 

 movement, sometimes rises and stiffens violently before dying, and 

 sometimes has real convulsions. All that, we have seen, depends on 

 the state of exhaustion of the animal, the time which the experi- 

 ment has lasted, etc. 



Autopsy shows hardly any interesting results. The blood is dark 

 everywhere, except in the pulmonary veins, where it absorbs 

 oxygen during the return to normal pressure. It never contains 

 free gases. 



