Sudden Changes in Pressure 885 



enlargement, check it in higher points (where autopsy finds them) 

 until finally respiration ceases; during this time, besides, the pul- 

 monary arteries are filled with free gases; asphyxia comes every- 

 where at the same time. 



But it has happened sometimes that the paralysis was localized 

 in the lower limbs, or at least has made only rather slow ascending 

 progress; so that death occurred only after several days (Exp. 

 DXXIV, DXXVI, DXXXIV) . If we consider the lack of care for 

 the animals, we may think that some might survive, though para- 

 lyzed, as happens to some divers. 



At death, there was found, as we have already noted, a more 

 or less extensive softening, in the midst of which bubbles of gas 

 (Exp. DXXVI) were sometimes seen even after 4 days, and which 

 were surrounded by the inflammatory processes which had caused 

 death. I call attention to the rapidity with which a softening oc- 

 curred so great that the spinal marrow was liquid like cream; in 

 Experiment DXXIV, it was less than 24 hours. 



I shall only mention to the reader the remarkable physiological 

 symptoms which accompany these interruptions of the medullary 

 circulation and the following changes in metabolism. Those who 

 have had the patience to read the preceding experiments must have 

 noted the strange occurrences of an emission of bloody urine and 

 sperm, of contraction of the limbs, of constriction with exagger- 

 ated reflex movements of the anal and bladder sphincters, of sensi- 

 tivity retained after the loss of motility, etc. I shall only recall 

 here the curious point of the afferent and efferent conductivity of 

 the sciatic nerve, so much affected by the change in the corre- 

 sponding region of the spinal cord (Exp. DXXXIV) . I consider 

 that these softenings produced experimentally might contribute 

 greatly to the progress of the physiology of the spinal cord, and 

 render useful services to the medical diagnostician: it is a mine to 

 be worked which would be as prolific as the one which gave so 

 many useful results in the skillful hands of Professor Charcot. 



Some of the experiments reported above show that the presence 

 of bubbles of gas in the blood is not a necessary cause of death or 

 even of symptoms manifest to the eyes of the observer. Thus in 

 Experiment DXXXIX, in which the pressure was 3V2 atmospheres, 

 from the blood received under mercury in a test tube very small 

 bubbles of gas escaped, and yet the animal, decompressed in 1 

 minute, did not seem at all affected. Looking very closely and 

 using a magnifying glass, I even saw in one case (Exp. CLXXXIV) 



