362' Historical 



The day after our visit of December 5, keen pains appeared in 

 the left side, and we felt a rather severe painful discomfort for several 

 days afterwards. Since a chill or some other cause not connected with 

 the compressed air might have been acting, after we were quite free 

 from these pains, December 28, we were anxious to try the experiment 

 again, and when we left the shaft, we took the greatest precautions to 

 protect ourself from any chill. In spite of these precautions, the 

 next day, very noticeably at the same hour, that is, 20 hours after our 

 exit from the medium of compressed air, we felt in the right side pains 

 just like the former ones, which kept us numb for four or five days. 

 (P. 362.) 



We now come to the important Memoir, the first written by 

 physicians about these symptoms, in which MM. Pol and Watelle 1X 

 recount the effects of compressed air upon the miners during the 

 excavating at Avaleresse-la-Naville, at Lourches, in the grant of 

 Douchy (Nord). 



The authors took care to warn the reader that since their notes 

 were made without any intention of publication, they made their 

 observations without plan, without program, and consequently 

 without system. But they thought, and with good reason, that 

 their work would nevertheless present some interest and some 

 utility. 



During the exploitation, the total pressure rose to 4V4 atmos- 

 pheres. The compression was made in a quarter of an hour, the 

 decompression in a half -hour; 64 workmen took part in the work; 

 they usually stayed four hours consecutively in the apparatus, 

 twice a day. 



The authors described separately the physiological effects 

 which they observed in themselves and the pathological effects 

 experienced by the workmen: 



1. Physiological effects: Pains in the tympanic membranes; 

 slowing of the respiration and particularly a decrease in the 

 amplitude of the thoracic expansion, which became hardly per- 

 ceptible; slowing of the pulse, (from 70 to 55) ; increase of urinary 

 secretion. 



The authors also mention a "muscular sensation of a resistance 

 to be overcome, as if the unusual density of the ambient atmos- 

 phere hindered movement; the inability to whistle, experienced 

 above 3 atmospheres, is also attributed to an unexpected resistance, 

 experienced by the muscles of the tongue in compressed air. 



On the return and during the decompression, they experienced 

 a keen sensation of cold, a kind of panting; the pulse rose to 85. 



Pathological effects. Taking the observations as a whole, we 



