Sudden Changes in Pressure 865 



ature is 38°. The urine issues when the right sciatic nerve is stimu- 

 lated: no sugar. I kill the animal, which is very sick, by opening 

 the thorax. 



The left sciatic nerve is reddish, its vessels are bloodshot; in most 

 of its fibers the myelin is a little turbid and is beginning to separate. 

 The right sciatic nerve is intact. 



The spinal cord is softened in the region of the lumbar enlarge- 

 ment. Transverse sections show the following changes. Below the 

 enlargement, red dots in the gray matter; in the upper part of the 

 enlargement, where section is possible, we find complete suffusion of 

 the left posterior horn of the gray matter and suffusion in parts of 

 the horn on the right side; the antero-lateral and posterior columns 

 on the left are of a very marked yellowish-gray; all of it is very soft. 



Below the dorsal region, uniformly red appearance of all the gray 

 matter, which is less soft, with coloration spreading into the posterior 

 white matter, especially on the left; yellowish gray softening of the 

 left antero-lateral column and the posterior column. 



The alteration lessens as it goes upward and ceases above the 

 brachial enlargement; the cord there is firm, but a little suffused. 



Experiment DXXXV. August 3. Dog. 



At 8 atmospheres, the little apparatus, which supports the cannula 

 for drawing blood (Fig. 34, E), is violently thrown forward: the 

 pressure falls in 3 or 4 minutes. 



The dog comes out, runs a few steps, then falls and dies rapidly. 

 Gas in abundance in the right heart, but not in the left heart. 



Experiment DXXXVI. August 5. Pregnant bitch taken to 9V4 

 atmospheres, bled of 375 cc. of blood (See Exp. CLXXXIV) 1 ; decom- 

 pressed rapidly: takes a few breaths and dies. 



Both sides of the heart are full of gases almost completely free: 

 the stomach contains little gas. 



The hearts of the foetuses and their veins contain both gas and 

 a very dark blood. In the allantoid liquid abundant bubbles are float- 

 ing; the placenta is all torn by the gases; no gas in the amnion. 



Experiment DXXXV II. October 16. Dog which has already served 

 for Experiments DLXXVII and DLXXVIII (10 atmospheres, slow 

 decompression). From 1:10 to 1:45, taken to 7 atmospheres, decom- 

 pressed at 1:55 in 2 Vz minutes. 



Taken from the apparatus, is lively and seems to feel no painful 

 symptom. 7>Vz minutes after the decompression, raises its right front 

 foot and seems to be in pain. After 5 minutes, struggles, wavers in 

 its hindquarters, has an almost sudden erection. After 7 minutes, 

 enormous convulsive stiffening of the hindquarters, which one can 

 hardly bend. The tail moves and the front legs are not affected. 



The animal is recompressed to 7 atmospheres and decompressed 

 very slowly. (See Exp. DLXXXVIII.) Dies the next day. 



Experiment DXXXV III. October 18. Dog. 



From 2:25 to 3:10 compressed to 7 atmospheres, and left 7 min- 

 utes. Decompressed as rapidly as possible, in 2 minutes, from 3:17 to 

 3:19. Withdrawn from the apparatus, comes, goes, fawns; but at 3:21 



