Diving Bells and Suits 397 



Evidently the superficial capillaries and the arteries which are 

 nearest the skin are more subject to the effect of the outer pressure 

 and their caliber lessens. If one goes into compressed air with a 

 part of the mucous membrane or the outer tegument congested, the 

 congestion quickly disappears. In the diving suit, in spite of rubber 

 rings which clasp the wrists tightly, the hands are pallid. But al- 

 though the quantity of blood in the periphery is diminished, the 

 organs which by their position are less directly subjected to the action 

 of the compressed air have a more abundant circulation. Since the 

 lungs - are under the same conditions as the skin, they must receive 

 less blood than in the normal state. (P. 22-23) 



If one returns from a higher pressure to normal pressure, the 

 pulse rate accelerates, the pulse which was filiform regains its full- 

 ness, and if the difference in pressures was considerable, slight hem- 

 orrhages are sometimes observed. 



The agreement of authors on this question is perfect. We were 

 not able to follow the changes in the circulation during the act of 

 decompression, but we noted by a great number of observations that 

 at the moment of reaching the deck the pulse rate of the divers was 

 almost always more than 80 per minute. Out of 240 observations we 

 found it to be: 



Below 80 heartbeats 11 times 



From 80 to 90 heartbeats 103 times 



From 90 to 100 heartbeats 124 times 



From 100 to 109 heartbeats 2 times 



Half an hour afterwards, 203 times the pulse had returned to 

 nearly normal; 3 times it had fallen definitely below, and 34 tirnes it 

 was still between 75 and 80. 



Here, as in regard to respiration, we cannot attribute the accel- 

 eration of the rhythm to the act of ascent. As we have said, mus- 

 cular fatigue is almost absent because of the expansion of the air in 

 the suit and the slowness with which the diver ascends. (P. 24.) 



The secretions furnish him with the following observations: 



All authors, except MM. Foley and Frangois, note a greater secre- 

 tion of urine; I think that this opinion is correct. The divers whom 

 I have observed could not remain more than an hour and a half sub- 

 jected to a pressure of 20 meters of water without feeling the need 

 of urinating; sometimes they even urinated in their suits. The increase 

 of the salivary secretion was noted only by MM. Eugene Bertin and 

 Junod; as for me, I cannot form an opinion on this matter; in all the 

 French divers and in myself the salivary secretion was more abund- 

 ant than in the normal state; but the presence in the mouth of a rubber 

 apparatus intended to admit air accounts satisfactorily for this phe- 

 nomenon. 



After this series of purely physiological observations, M. Gal 

 reaches the study of dangers of high pressures. He divides the 

 diseases which one may attribute to the effect of compressed air 



