Symptoms of Decompression 701 



The first moments of the decompression gave rise to no dis- 

 agreeable impression. At 10:34 at a pressure of 70.5 cm. of mercury 

 I found a pulse rate of 80 in M. Sivel; and very shortly after, at G8 

 cm., 92 in myself. At 1:40, pressure 56 cm., the pulse rate of M. Sivel 

 was 100; mine was also. At 1:44, pressure 51 cm., my pulse was 

 116, M. Sivel's 108. 



Beginning with a pressure of about 48 cm., oppression begins 

 to be quite perceptible. I become lazier and am satisfied with con- 

 sidering what effects I feel. My face feels hot, and so does M. Sivel's 

 at a pressure of about 44 cm. Besides, I have prickly sensations in 

 my head, an itching which feels like a scalp affection. Mental energy 

 is not at all weakened, for we are gay and talkative. 



At 1:40, about 41 cm., M. Sivel breathes oxygen from the bag, 

 not from necessity, but to lessen the considerable tension of the con- 

 tainer, which is ready to burst. At a pressure of 40 cm., I feel un- 

 comfortable, my head seems to be in a vise, and I feel as if I were 

 pressing my forehead hard against a bar of small diameter. My pulse 

 rate is 135. 



At 1:57, at a pressure of 39 cm., I breathe some gulps of oxygen 

 from the bag which M. Sivel holds out to me. I feel better and my 

 pulse rate falls to 128, although the decompression is continued. 



We pass each other the oxygen bag. My companion uses it un- 

 til the maximum decompression, 5 or 6 times, often very freely, and 

 I do 3 or 4 times, in a way that is generally more moderate and 

 even awkward, for, feeling at first a certain distaste for breathing 

 this gas which smells of rubber, I lose a fairly large quantity of it. 

 However, as the pressure lowers, I overcome this repugnance more 

 easily, and feel instinctively the necessity of absorbing this gas. At 

 38 and 37 cm., my pulse rate is 128 after breathing oxygen; at 35 

 cm., it is 132. It is certain that if oxygen were not inhaled, it would 

 be higher. 



In M. Sivel, the absorption of the oxygen produced the follow- 

 ing effects: the bell seemed to him to be moving as if he were drunk, 

 and this effect lasted for several seconds; he had a slight sensation 

 of seasickness. Then this discomfort vanished and his mind became 

 keener than before the oxygen was inhaled. 



In me, the same impressions were present, but in a greater de- 

 gree. Moreover, below 35 cm., my vision, which was growing dull, 

 became very noticeably keener after the absorption of oxygen. I 

 saw clearly after having seen dimly; the interior of the bell seemed 

 suddenly to become lighter. 



At these low pressures, the mind had become very dull in both 

 of us, but particularly in me. During the four minutes preceding the 

 time when we reached 30.4 cm., I could only note down the pressures 

 which M. Sivel dictated to me very loudly, and the simplest calcula- 

 tions seemed very difficult to me. I was very deaf and had to have 

 the pressure figures repeated several times. The air no longer seemed 

 to conduct sound. 



At 11:08, at a pressure of 30.4 cm., neither M. Sivel nor I was 

 saying a word. However, we had been very gay, very talkative and 

 active to about 37 cm. It is true, we no longer had any oxygen, and 



