190(5.] Influence of Increased Barometric Pressure on Man. 445> 



Time. 



Temperature of 

 chamber. 



Pressure. 



Notes. 



10.40 A.M. 



57° F. 



+ 





10.50 



62 







10.55 





+ 16 lbs. 



Voice becoming nasal and metallic. 



11.5 



67 







11.20 



69 



+ 62 lbs. 



Sensation of slight vertigo. 



11.34 



68* 



+ 92 „ t 



Between 11.25 and 11.40 articulation was difficult, and the subject experienced some 





trouble in making himself heard through the telephone. 



11.55 





+ 77 lbs. 





12 noon 



65 







Subject quite comfortable, voice still nasal but easier to produce and much more audible. 



12.4 p.m. 





+ 72 lbs. 





12.10 







Pulse, 40. Respirations, 9 per min. 



12.37 



64 



+ 52 lbs. 





1.0 



63 



+ 31 „ 



Voice much better. 



1.20 



63* 





Pulse, 42. 



1.51 





+ 





Period of compression, 54 minutes. 



Period of decompression, 2 hours 17 minutes. 



On quitting the chamber some itching was perceived in both forearms, 

 especially the right. In about 20 minutes neuralgic pains were felt, localised 

 in the radial side of the left forearm. These pains gradually increased in 

 intensity, spreading up the arm ; then, after remaining moderately intense 

 for five minutes, they gradually subsided. Several minutes later (about 

 one hour after leaving the chamber) similar pain was experienced in the 

 right forearm. This however did not spread upwards, was less severe and 

 quickly subsided. An hour and a half after leaving the cylinder the subject 

 felt quite well and no subsequent ill effects resulted. As will appear later, 

 there is good reason to suppose that the slight discomfort present at the 

 conclusion of this experiment is attributable to the fact that the subject 

 remained almost completely at rest during decompression. We may therefore 

 conclude that an adult may be safely submitted to a total barometric pressure 

 of at least 7 atmospheres, which is, we believe, a limit higher than any 

 previously reached. 



In the course of our investigation the following pressures have been 

 attained : — 



Subject, L. H. Subject, M. G. 



75 lbs., once. 90 lbs., once. 



60 „ twice. 75 „ three times. 



45 „ „ 60 „ four „ 



30 „ four times. 45 „ five „ 



30 „ seven „ 

 * Wet cloths were placed on the cylinder at this time. 



t This reading was verified by Mr. J. A. Craw, who was present during the whole 

 course of the experiment. 



