CHIRURGERY. 429 



that is opacity of the cornea ; cataract, or opacity of the crystalline 

 lens ; glaucoma, or disease of the vitreous humor ; and amaurosis, 

 or gutta serena, a disease of the retina, or optic nerve. Albugo, and 

 cataract, may be removed ; the former by a careful application of 

 nitrate of silver, at intervals ; and the latter, either by extraction, or 

 by the operation of couching ; which consists in pushing the crystal- 

 line lens aside, so that it shall not interfere with regular vision. 



The diseases of the ear, the care of which belongs to the Jlurist, 

 are less numerous than those of the eye ; but, like them, often require 

 surgical operations. The introduction of foreign substances into the 

 ear, sometimes thoughtlessly effected by children, may cause serious 

 injury, and deafness, unless speedily removed. When insects pene- 

 trate the ear, they may be killed by dropping in olive oil, or a 

 decoction of tobacco ; and they may then be removed, like other 

 substances, by syringing, or by means of the forceps, or probe. 

 Deafness may also be produced either by too abundant, or too scanty 

 secretion of cerumen, or wax of the ear; and when this aggregates 

 and hardens, it may be softened by means of olive oil. 



To the Dentist, belongs that division of Surgery which relates to 

 operations on the teeth. The teeth, are organized substances, con- 

 taining nerves, and vessels, by means of which they grow : and the 

 pressure of these vessels, when swollen, causes the very common 

 complaint of odontalgia, or toothache ; which sometimes results 

 from injury or decay of the teeth, and sometimes from inflammation, 

 as in colds or fevers. Hence, toothache is often removed by subdu- 

 ing the inflammation : but when it is chronic, or long continued, it 

 indicates exposure or disease of the nerves ; and when the teeth are 

 decayed beyond repairing, the last resort is their removal. Teeth 

 often decay from injury to the enamel ; which is a peculiar coating, 

 protecting the sensitive parts ; and which being gradually supplied, 

 is not easily restored where it is once worn or broken through. 

 Young persons should be cautioned against biting hard or rough 

 substances, lest they suffer severely for this imprudence in after life ; 

 and, for a like reason, we prefer prepared chalk, as a dentifrice, in 

 habitually cleansing the teeth, and removing acid matter, rather than 

 charcoal, which may injure the enamel. 



