360 Historical 



One of the strangest results is that one suddenly loses the power 

 of whistling under the pressure of 2% to 3 atmospheres. 



The functions of nutrition, respiration and circulation do not seem 

 perceptibly altered in compressed air. At the time of our first visit, 

 we thought that we found an increase in the pulse rate of every one 

 subjected to the experiment; but on our second visit, the result of a 

 more accurate observation, made by a member with much experience 

 in taking the pulse, was completely negative .... 



The respiration is neither slower nor faster. It seems that it is not 

 more active and that the animal heat is not increased. The blood too 

 gushes out under normal conditions. In a word, the most surprising 

 thing is that there are very few changes in the vital functions. The 

 workmen assert that they climb the ladder more easily and are less 

 out of breath when they reach the top. This cannot result from the 

 rather slight loss in their weight. Is it possible that they can hold 

 their breath longer because of the greater density of the gas inhaled 

 at each respiration? On the other hand, they maintain that they 

 become much more tired when working in compressed air than in 

 open air. We think that this is the result of the very great humidity 

 of the atmosphere of the shafts, which hampers the insensible perspi- 

 ration and promotes the more rapid secretion of sweat in those who 

 have to exert their muscular powers in such a medium. Perhaps this 

 humidity would also explain the somewhat severe pains in the ar- 

 ticulations experienced by some workmen a few hours after leaving the 

 shaft .... 



We may conclude that there is no serious danger in staying several 

 consecutive hours for several successive days in air compressed to 3 

 atmospheres. 



Our author says nothing of the duration of the decompression; 

 he seems, moreover, to pay more attention to "the passing from a 

 low to a high pressure": he only says that they opened the cock 

 gradually. 



In a second communication to the Academy of Sciences, M. 

 Triger s repeats his former observations. He adds to them the 

 following data: 



Everyone talks through his nose and loses the power to whistle 

 at 3 atmospheres. To ascertain the effect of compressed air on a 

 stringed instrument, I had a violin taken down into the shaft and it 

 was found that at the above pressure the sound lost at least half 

 of its intensity. 



Then comes the first suggestion of the rather serious symptoms 

 of decompression: 



I should say here that two workmen, after passing 7 consecutive 

 hours in compressed air, experienced rather keen pains in the arti- 

 culations, half an hour after leaving the shaft. The first complained 

 of a very sharp pain in his left arm, and the second experienced a 

 similar pain in his knees and left shoulder; rubbing with spirits of 



