DISEASES OF THE ALIMENTARY SYSTEM. 205 



be applied. Internally, tonics and stimulants are indi- 

 cated. 



PTYALISM— SALIVATION.— Ptyalism or salivation is 

 an abnormal increase in the amount of secretion of saliva, 

 which dribbles away continuously, or collects in foam around 

 the mouth. 



We do not apply the term salivation or ptyalism to the 

 escape of saliva from the mouth resulting from inability to 

 swallow it. 



The secretion of saliva is a reflex process, and salivation 

 depends therefore either upon peripheral irritation, or upon 

 undue action of the salivary nervous centres, or on both 

 these conditions. 



It is generally dependent on peripheral irritation occur- 

 ring in some diseases of the mouth, pharynx, throat, and 

 other organs ; and may also result from irritation caused by 

 irregularity of the teeth, or foreign bodies in the mouth. 

 It may occur in rabies and tetanus, and in some instances no 

 assignable cause is found. 



Finally, it may be due to the administration of certain 

 drugs. 



Treatment. — In all cases the cause should be ascertained 

 and removed, if possible. 



If there be any irregularity of the teeth, this should be 

 attended to. 



Gargles of alum or chlorate of potash are often very useful 

 in these cases. If the salivation continues, belladonna is 

 worthy of trial. 



ACUTE PHARYNGEAL CATARRH.— Inflammation of 

 the mucous membrane and submucous tissue of the fauces 

 and pharynx are common in influenza, strangles, and other 

 specific fevers in ^vhich the air-passages are involved. 



This form of pharyngitis we have already alluded to, as 

 also we have to inflammation of these parts occurring as 



