VOL. XC.] PHILOSOPHICAL TRANSACTIONS. 567 



membrane, in a radiated manner, from the bony rim which surrounds it, to- 

 wards the handle of the malleus, to which the central part of the membrane is 

 firmlv attached. This discovery in the elephant having led to that of a similar 

 construction in the human membrana tympani, it may not be improper to relate 

 the circumstances by which I became engaged in the investigation of the organ of 

 hearing in that animal. Three different opportunities have occurred of dissecting 

 the elephant in London, by the deaths of those which had been presented to his 

 Majesty, and were kept at the King's stables at Pimlico. One of them was given 

 to the late Dr. Hunter; one to his brother Mr. J. Hunter; and the third to Sir 

 Ash ton Lever. 



From my being connected with Mr. J. Hunter's pursuits in comparative anatomy, 

 I was employed throughout the whole of these dissections, and became extremely 

 desirous of examining the internal parts of the ear, the structure of that organ in 

 the human body having at a very early period particularly engaged my attention;* 

 but neither Dr. Hunter nor his brother could be prevailed on to sacrifice so large a 

 portion of the skull as was necessary for the purpose. When Mr. Corse arrived 

 from Bengal, last year, and mentioned his having brought over a number of skulls 

 of elephants, in order to show the progress of the formation of their grinding teeth,-f- 

 the desire to examine the organ of hearing in that animal recurred to me so strongly, 

 that I requested to have one of the skulls for that purpose, and Mr. Corse very 

 readily and obligingly complied with my request. After having examined the organ 

 in the dried skull, the want of the membrana tympani, and of the small bones, 

 made the information thus received of a very unsatisfactory nature, and increased 

 trfe desire of seeing these parts in the recent head. In considering how this could 

 be done, I recollected a mutilated elephant's head, preserved in spirits, which had 

 been sent to Mr. Hunter; but which, from the multiplicity of his engagements 

 had remained neglected in the cask at the time of his death, and in the following 

 year was dried, to show the proboscis, that it might not be altogether spoiled. 



On examining this dried head, the bones had been so much broken, that one of 

 the organs of hearing was altogether wanting; the other however was fortunately 

 entire; and the membrana tympani and small bones, having been little disturbed in 

 the drying of the parts, remained nearly in their natural situation. The membrana 

 tympani, and every other part of the organ, were found to be much larger in pro- 

 portion than in other quadrupeds, or in man; differing in this respect from the eye 



* In 1776, I injected the cochlea and semicircular canals of the human ear with a composition of 

 wax and rosin. This was done by placing the temporal bone in the receiver of an air-pump, the upper 

 part of which was in the form of a funnel, rendered airtight by a cork being fitted into its neck, and 

 surrounded with bees' wax. After the air had been exhausted, the hot injection, poured into the funnel, 

 melted the wax, and the cork was pulled out by means of a string previously attached to it; the injec- 

 tion immediately rushed into the receiver, and was forced, by the pressure of the atmosphere, into the 



cavities of the temporal bone. + On this subject, a very ingenious paper has been since published 



by him, in the Phil. Trans, for 1799.— Orig. 



