DEAFNESS PRODUCED IN DIVING-BELLS. 231 



supposes that this excessive tension of the drum 

 of the ear, when produced by the compressed air 

 in the diving-bell, will also produce a corre- 

 sponding deafness to low tones. This curious ex- 

 periment has been since made by Dr. Colladon, 

 when descending in the diving-bell at Howth, in 

 1820. "We descended," says he, "so slowly 

 that we did not notice the motion of the bell; 

 but as soon as the bell was immersed in water, 

 we felt about the ears and the forehead a sense 

 of pressure, which continued increasing during 

 some minutes. I did not, however, experience 

 any pain in the ears ; but my companion suffered 

 so much that we were obliged to stop our descent 

 for a short time. To remedy that inconvenience, 

 the workmen instructed us, after having closed 

 our nostrils and mouth, to endeavour to swallow, 

 and to restrain our respiration for some moments, 

 in order that, by this exertion, the internal air 

 might act on the Eustachian tube. My com- 

 panion, however, having tried it, found himself 

 very little relieved by this remedy. After some 

 minutes, we resumed our descent. My friend 

 suffered considerably ; he was pale ; his lips were 

 totally discoloured ; his appearance was that of a 

 man on the point of fainting ; he was in involun- 

 tary low spirits, owing, perhaps, to the violence 

 of the pain, added to that kind of apprehension 

 which our situation unavoidably inspired. This 

 appeared to me the more remarkable, as my 

 case was totally the reverse. I was in a state 

 of excitement resembling the effect of some 

 spirituous liquor. I suffered no pain ; I experi- 

 enced only a strong pressure round my head, as 

 if an iron circle had been bound about it. I 



