460 Historical 



During and after the decompression, all the gases dissolved in 

 excess in the blood, because of the compression of the air, will tend 

 to escape from the blood with a force the amount of which will be 

 greater in proportion to the increase in the pressure undergone, the 

 stay in compressed air being equal. That is a necessary result of the 

 laws of physics dealing with the solution of gases in liquids, and we 

 have a common and frequent example of it in the speed and force 

 with which the carbonic acid escapes from a charged water when 

 the cork is removed from the bottle containing it. (P. 58.) .... 



The particles of gas which have regained the aeriform state all 

 through the blood system remain mechanically blended with the 

 liquid molecules which held them in solution before; it follows that the 

 blood becomes an expansible mixture which constantly struggles to 

 distend these vessels and to increase in volume. The ultimate result 

 is a general and more or less important turgescence of the blood 

 vessels and a more or less threatening imminence of hemorrhages. 

 And as the gases dissolved in excess separate from the humors as they 

 do from the blood, a general tendency to emphysema will result. 



Let us now attribute to the expansive power of the liberated gases 

 a sufficient intensity, and it does not need to be great, if it is favored 

 by individual peculiarities, and then the threat of hemorrhage and 

 the tendency to emphysema will become facts. We shall have all the 

 cases of hemorrhage and emphysema observed in ascents of lofty 

 mountains, or in balloon journeys, or in compressed air apparatuses. 

 (P. 59.) 



Supported by this excellent basis of reasoning, M. Bucquoy 

 easily explains the emphysemas observed at Douchy, the hemor- 

 rhages, and the muscular and articular pains, in regard to which he 

 quotes the following very interesting observation: 



One day when I was observing a workman who was having severe 

 pain in one knee, I saw the dry cupping-glasses placed around the 

 articulation falling off one after the other, although they had been 

 carefully applied by the orderly, a very skillful man. They were 

 replaced several times and remained in place only a certain time; the 

 patient was then considerably relieved. The elimination of the free 

 gases explains both the falling of the first cupping-glasses and the 

 prompt disappearance of the pain through their repeated application. 

 (P. 62.) 



M. Bucquoy finally with good reason advises the engineers to 

 take all precautions necessary to make the decompression suffi- 

 ciently slow. 



We reported above (page 379) the story of the patient of M. 

 Hermel, 20 who was seized by paralysis when he was leaving the 

 caissons of the bridge piers of the Scorff*, near Lorient. The author 

 attempted, when he summarized the preceding observations, to 

 explain the symptoms noted; we shall see that he is not very suc- 

 cessful in his attempts. 



