672 Experiments 



I add that under the influence of pressures which are very weak 

 and very quickly reached, I have sometimes seen nasal and pul- 

 monary hemorrhages. But this is a very rare symptom in animals; 

 in fact, it is not as common in man as is ordinarily stated. 



3. Digestion. 



As a certain degree of decompression is approached, travellers 

 have experienced nausea; I have likewise seen my animals stagger, 

 wag their heads with evident distress, and vomit. Almost all birds 

 showed this symptom. 



Animals subjected to extreme decompressions, and especially 

 herbivores, were swollen in a very remarkable way by the expan- 

 sion of their intestinal gases. It seemed to me, in some cases, that 

 this swelling was great enough to act even on the respiration and 

 hamper its movements. 



I have verified upon myself this disagreeable swelling, in Ex- 

 periment CCXXX and in several others of the same sort reported 

 in Subchapter III; but it never brought serious inconvenience, 

 when the garments which confined the waist were unfastened and 

 opened; besides, the gases easily found vent through the two in- 

 testinal orifices. 



I even tried direct experiments, to obtain ocular evidence of 

 this evacuation of gas. 



Experiment CCXXXI. December 10. A dog, which had just been 

 killed by direct application of electrical stimulation to the heart, was 

 fastened on a trough and placed in the decompression cylinders. Into 

 its rectum was inserted a glass elbow tube, which by means of rubber 

 packing completely closed the anus. The other end of the tube was 

 immersed several centimeters deep in a glass full of water. 



The decompression was then begun, and as fast as the barometer 

 fell, bubbles of gas burst on the surface of the water, and the greater 

 the speed of the decompression pump, the more rapidly the bubbles 

 followed each other. 



However, the belly was visibly swelling. 



On return to normal pressure it suddenly collapsed, and water 

 entered the rectum. 



Experiment CCXXXII. February 27. Dog killed by hemorrhage, 

 and prepared like the dog in the preceding experiment. It had also 

 in its esophagus a tube immersed a little way in the water. 



At the very first strokes of the pump, the air left the anus con- 

 stantly; several times the machine was stopped, and the gaseous evac- 

 uation ceased immediately. But no gas left by the esophagus. 



The pressure was lowered to 30 cm. in 2 hours and 20 minutes. 



On return to normal pressure, the belly collapsed. 



