446 Mr. Cooper's Observations on the 
Thirdly, It is right to inquire if the deafness was immediately 
preceded by any complaint in the throat. 
Lastly, In a closed Eustachian tube there is no noise in the 
head, like that which is hereafter described as accompanying 
nervous deafness. 
The causes of deafness are extremely numerous; and many 
of those which affect only the meatus auditorius, the membrana 
tympani, the cavity of the tympanum, and the Eustachian tube, 
admit of relief from surgical assistance. 
But there is one species of deafness in which, as it depends, 
like the gutta serena of the eye, upon an affection of the nerve, 
it would be as absurd to expect relief could be derived from 
any operation upon the membrana tympani, as it would to sup- 
pose that a person diseased in the optic nerve could be restored 
to sight by extracting the cataract. This species of deafness 
occurs more frequently than any other, happening generally in 
old persons ; but sometimes also, in the delicate and irritable, in 
the earlier stages of life ; I have known it produced by anxiety 
and distress of mind. Its approach is generally gradual : the 
person hears better at one time than at another; a cloudy day, 
a warm room, agitated spirits, or the operation of fear, produce 
a considerable diminution in the powers of the organ. In the 
open air, the hearing is better than in a confined situation ; in a 
noisy, than in a quiet society; in a coach when it is in motion, 
than when it is still. A pulsation is often felt in the ear ; a noise, 
resembling sometimes the roaring of the sea, and at others the 
ringing of distant bells, is heard. 
This deafness generally begins in a diminished secretion of 
the wax of the ear, which the patient attributes to some unusual 
-exposure of the head to cold ; and this continues so long as the 
