Theories and Experiments 451 



Let us note, in passing, as a sort of curiosity, the idea suggested 

 by these authors that "the unaccustomed density of the compressed 

 air would hamper walking," and that the difficulty in talking in the 

 cylinders, which they had observed, would also result from "this 

 unexpected resistance to muscular contractions instinctively gauged 

 by habit." (P. 250.) 



Now comes the explanation of the symptoms produced by de- 

 compression. The physicians of Douchy attempt, according to their 

 expression, "to discover the meaning of the symptoms observed, 

 and to determine, by interpreting them, the nosologic individuality 

 which they characterize." Now they say: 



This task is easy to accomplish, or rather it is already accom- 

 plished. 



In fact, if we except the muscular pains, at least in the cases in 

 which, being isolated, and unaccompanied by any indication of a dis- 

 turbance of the nervous centers, they were probably produced by the 

 impression upon the capillaries of this system of a blood with an 

 excessive oxygen content; 



If we also except the gastric symptoms, which have sometimes 

 seemed purely sympathetic, and sometimes, in our opinion, have been 

 caused by the very copious ingestion of the products of combustion, 

 it seems very clear that they have always been above all the expres- 

 sion of a state of congestion of the brain and the lungs. 



We shall not strive to demonstrate, with symptoms at hand, this 

 proposition in regard to which the autopsy of Heraut admits no doubt, 

 and which will gain an over-abundance of evidence from the results 

 of a second autopsy. 



Pulmonary and cerebral congestion is therefore the principal re- 

 sult of the compression of the air; it is its most important morbid 

 result, the source from which the fundamental therapeutic indications 

 are derived. 



We purposely omit mention of the congestions of the liver, the 

 spleen, and the kidneys, noted in the autopsy reported above, and 

 which will be repeated in the following one; they were not revealed 

 by symptoms, except that of the kidneys which caused excessive 

 secretion. (P. 259.) 



So the serious symptoms experienced by workmen are the con- 

 sequence of visceral congestions. But what can be the cause of 

 these congestions? The compression, they reply, as an agent of 

 the mechanical class; at least, that is what is clearly expressed by 

 the following passage: 



Since, when the atmospheric pressure is much decreased, the 

 blood flows towards the exterior and escapes from the capillaries, 

 there should result from the compression of the air visceral conges- 

 tions, deep hyperemias. For contrary influences, opposite effects: 

 contraria contrariis. 



