Symptoms of Decompression 675 



see, in the moments which precede death, the intestines twisting 

 in the belly in violent peristaltic movements. 



5. Nutrition. 



All the phenomena which we have just reviewed are only the 

 consequences of disturbances of the nutrition of the tissues, dis- 

 turbances due to the lessened quantity of oxygen in the blood. Our 

 experiments on superoxygenated atmospheres have shown, in fact, 

 that decompression as a physical agent plays a role that is almost 

 negligible, and that the question is exclusively of a chemical 

 nature. 



We ought therefore to study carefully these nutritive dis- 

 turbances, which manifest themselves so clearly to us by the lower- 

 ing of temperature. We shall therefore inquire into the modifica- 

 tions undergone by the chemical phenomena of respiration: 1.) 

 oxygen absorption, which is the primary factor; 2.) carbon dioxide 

 excretion, which measures the energy of the intra-organic combus- 

 tions; and 3.) the renal excretion, which can also serve as a measure 

 of the chemical activity of the living body. 



1. Chemical phenomena of respiration. The numerous experi- 

 ments reported in Chapter I on the death in closed vessels of ani- 

 mals subjected to more or less weak pressures make it possible 

 for us to calculate easily the quantity of oxygen consumed and the 

 quantity of carbonic acid exhaled, per unit of time, for each animal 

 species, or for each kilogram of animal. I shall do so in a moment, 

 taking into account only the experiments in which the behavior 

 of the animal has been noted, for it is quite evident that results can 

 be modified, even reversed in their general direction, by the 

 single fact of a considerable uneasiness compared to an absolute 

 repose. 



But it seemed to me desirable, for this delicate verification, to 

 carry out special experiments, in which special precautions should 

 be taken. Besides, the experiments of Chapter I end in death, and 

 although comparable in this respect, they cannot be as convinc- 

 ing as those in which the animals survive. 



Here are some of these new data. 



Experiment CCXXXIV. June 30. Rats of the same litter, each 

 weighing 50 grams. 



A. Confined from 4:16 to 4:58 (42 minutes) under an airtight 

 bell, containing 3.2 liters; normal pressure. 



B. Confined from 4:34 to 5:18 (42 minutes) under a bell of 7.1 

 liters, in which the pressure is rapidly brought to 34 cm. The volume 

 of the bell corresponds to 3.17 liters at normal pressure. 



