102 ON THE MEMJ5RAN4 TYMFANI 6P TJJE EAR. 



making it into an emulfion with twelve fweet and four bitter 

 almonds, a^jd a little orange peel. 

 Suet obtained Another advantage to be derived from thefe refufe bones ij 

 bonc5 ' ftje fat. Before grinding them to extrad the jelly, Mr. P. 

 chops them into pieces about an inch long with a cleaver, 

 throws them into a kettle of boiling water, and lets them boil 

 about a quarter of an hour. The fat obtained in this manner 

 from fixteen pounds of rump and edge bones weighed, when 

 cold, two pounds ; and from the fame quantity of the bones 

 of the joints he obtained four pounds of folid fat. This, he 

 obferves, when frefti, may be ufed for various culinary pur- 

 pofes ; and when it has been kept for fome time expofed to 

 the air, it becomes very good tallow for making candles. 



V. 



Obfervations on the Effecls which take Place from the Dejlruclion 

 of the Membrana Tympani of the Ear ; with an Account of an 

 Operation for the Removal of a particular Species of Deafnejs. 

 By Mr. Astley Cooper. * 



Injury or lofs of X"\FTER referring to a former paper, in which he had 



tympani does not P rovet L by facts, that an aperture in the membrana tympani 



occafion deaf- does not diminifh the faculty of hearing, and that a complete 



4eft rudion of the membrane does not occasion a total lofs of 



that fenfe, Mr. Cooper obferves, that there are various caufes 



Various caufes by which the membrane may be injured or deflroyed. Of 



: ur „ "thefe the moit common is fuppuration in the meatus audito- 



rius. In perfons of a delicate confiitution and irritable habit 



the ear-wax is liable to be hardened, gradually bringing on 



deafnefs, and then exciting inflammation and fuppuration. 



If this be not remedied, not only the membrane lining the 



meatus, but that of the tympanum alfo, will be deflroyed, 



the fmall bones of the tympanum be difcharged, and fome- 



times confiderable exfoliations take place. At Fig. 4, PI. VI. 



is a view of the membrane of the tympanum lacerated by a 



blow on the head ; probably from the air being driven into 



the meatus with violence. Children often introduce fmall 



Jlones, pieces of flate pencil, and even pins, into their ears, 



* Abridged from the Philofophical Tranfa&ions, 180>, p. 435; 

 I in 



