500 DISEASES AND INJURIES OF THE FACIAL REGION. 



According to Percivall, salivary calculi are mainly composed of 

 the carbonates and phosphates of lime. I have only one speci- 

 men in my possession, presented by Mr. Gloag, and it is composed 

 of organic matters, namely, albumen, mucus, and cholesterine 

 with a mere trace of salts. 



EXCESSIVE SECRETION OF SALIVA — PTYALISM. 



This results from disease of the teeth ; some peculiar foods, 

 as green food charged with mustard ; mercurialism ; any source 

 of irritation in the mouth ; from the poison of epizootic aphthce; 

 and rinderpest. 



Mercurial ptyalism is easily induced in horned cattle by 

 small doses of calomel, and by mercurial dressings to the skin. 

 In the horse, larger doses are required ; although in one case 

 which came under my notice two drachms of calomel were suffi- 

 cient to cause alarming salivation and other signs of mercurial 

 poisoning. 



The treatment in all cases is the removal of the cause, re- 

 peated wasliings of the mouth with cold water, and mild as- 

 tringents, such as vinegar, borate of soda, or alum. 



RANULA 



Consists in the formation of a cyst in one of the ducts of the 

 sublingual gland, varying in size from a walnut to a hen's egg, 

 containing a ropy fluid. (See chapter on Tumours.) 



EPULIS. 



(See Photo-lithograph, Plate IV., Fig. 1.) 

 A tumour of the gum, often of a simple growth of the same 

 consistence as the structure from which it grows, and not hkely 

 to be reproduced when the exciting cause has been removed, 

 and the disease extirpated. Its frequent cause is caries of 

 some parts of the molar teeth. The lower jaw is its most com- 

 mon seat ; it commences at the root of the molars, or in the 

 alveolar ridges. The size and extent of epulis are various ; it 

 may be confined to the gum between two teeth, or it may 

 involve several, if neglected, and partake of a malignant character, 

 as the specimen portrayed in Photo-Uthograj:)!!, Plate IV., Fig. 2. 



