Descents in a Diving Bell. 327 
Mr. Clifford: had, for many years, been afflicted with rheumatic 
pains. During the several weeks he was- engaged in this enterprise, 
he was remarkably free from this complaint. 'The first time he de- 
scended in the diving bell, he happened to be considerably affected 
with his disorder ; but, on coming out of it, he was entirely relieved 
‘from pain, insomuch that he walked, directly after, six miles, without 
inconvenience. This was an exertion, which he had not thought 
himself able to make, for several years before. 
Could a series of experiments, be instituted, on proper subjects, 
who will venture to say, that the result would not be such, as to ren- 
der a submarine descent, in a SS ‘diving bell, a frequent 
and favorite adventure? 
Observations by Dr. Mease. 
S 
The painful sensation in the ear mentioned in the preceding paper, 
is invariably experienced by those who descend in diving bells; ow- 
ing to the compression of the condensed air on the membrana tympa- 
ni, but the means of preventing it, which were discovered by Messrs. 
Clifford and Tripe, are not mentionedin any of the accounts of diving 
which I have read, nor do the writers of them notice the “ shock” 
felt by the Portsmouth divers which immediately preceded their re- 
lief from the pain. Dr. Hamel of St. Petersburgh states, that he 
was relieved of the pain by making exertions to admit air through the 
Eustachian tube into the ears, but, succeeded in accomplishing this 
at first, only on one side, when the air rushed into the cavity of the 
right ear, and the pain ceased instantly ; when in the diving bell, he 
was not aware of the simple way in which it is effected. Dr. 
Wollaston informed him, that nothing is wanted but to swallow the 
saliva, as may be seen from the following simple experiment. Close 
your nostrils with the fingers, and suck, with the mouth shut: air will 
come through the Eustachian tube from the ear, and you feel pres- 
sure on the membrana tympani, which prevents you from hearing dis- 
tinctly. As the end of the tube nearest to the mouth, acts like a 
valve, this sensation will often remain even after you have ceased 
sucking. ‘To remove it, nothing is wanted but to swallow saliva, 
whereby the action of the muscles seems to open the end of the tube, 
and then the air rushes in to re-establish the equilibrium : during the 
descent of the bell Dr. Hamel says that the pain returned, but as he 
repeated his exertions to open the Eustachian tube, the air at inter- 
