Symptoms of Decompression 679 



reagent and a vacuum), sometimes by that of M. Yvon (by hypo- 

 bromide of soda) . 



Dogs were used as subjects of my experiments. The animal, 

 enclosed in advance in the cylinders in which the decompression 

 was to be carried on, was fed on a definite diet for two or three 

 days; then we calculated the quantity of urea excreted in 24 hours, 

 drawing the urine two mornings in succession, because dogs which 

 are confined urinate at very irregular intervals. Of course, the 

 urine voided spontaneously by the animal was carefully collected. 

 The decompression having been maintained for several hours, we 

 made a new analysis including the urine of the day from the 

 morning of the experiment to the next morning. Sometimes, we 

 also collected in the same way the urine of the 24 hours following. 



Here are some of the results obtained. 



Experiment CCXXXVI. July 3. Dog weighing 12 kilos; eats every 

 day, between 7 and 8 in the morning, 250 gm. of bread and 250 gm. 

 of meat boiled together with 500 gm. of water. 



July 4, at 10 in the morning, dog's bladder emptied. 



July 5, bladder emptied again at the same hour; he has not uri- 

 nated spontaneously; we obtain thus 260 cc. of urine, which treated 

 by the Yvon method give 7248 cc. of nitrogen. 



We conclude then that he voided 19.4 gm. of urea. 



On that day, from 11 to 6, the animal was subjected to a pressure 

 of 38 cm. 



After he had left the apparatus, catheterization brought 100 cc. of 

 urine, containing 7.4 gm. of urea. The next day at 11 in the morning, 

 another catheterization, giving 80 cc. of urine, with 4.4 gm. of urea. 



Produced then in these 24 hours only 11.8 gm. of urea. 



The next day (July 7), catheterized at 1:15; the urine, added to 

 what he voided during the night, amounts to 240 cc, containing 15.4 

 gm. of urea. 



Experiment CCXXXVII. Same dog, kept on the same diet. 



Catheterized July 7 at 1:15, as has just been said, then July 8 at 

 10:30 (21 hours), gives 246 cc. of urine containing 19.6 gm. of urea. 



July 8, from 10:55 to 4:45, is kept at 38 cm. pressure. 



July 9, at 1:15, has given (in 27 hours) 385 cc. of urine containing 

 24.7 gm. of urea. 



If we reduce these secretions to their proportionate value for 24 

 hours, we find: 



At normal pressure: 22.4 gm. 



At a half-atmosphere, 21.9 gm. 



Experiment CCXXXVIII. July 13. Same dog, subjected to same 

 procedure. But he is tired of being confined. 



From July 13, at 7:45 in the morning (fasting) to July 14 at 8 in 

 the morning (fasting) voided 200 cc. of urine, giving 13 gm. of urea. 



July 14, from 8:30 in the morning to 5:45 in the evening, kept 

 at a pressure varying from 30 cm. to 35 cm. Does not seem weakened. 



