458 DISEASES OF THE MOUTH. 



account of the severity of the original disease. If the swelling be red, 

 and the patient winces when we press on the tumor, we should apply 

 compresses of cold water or ice. When there is fluctuation, warm 

 poultices and early opening of the abscess are indicated. 



CHAPTER XI. 



SALIVATIO N P T Y A L I S M . 



STRICTLY speaking, we have no right to consider salivation as a 

 distinct disease (it forms a symptom of a great variety of affections), 

 but we follow custom in giving a separate chapter to tlie anomalies of 

 secretion of the salivary glands. The quantity of saliva secreted in 

 twenty-four hours is usually estimated at ten to twelve ounces, but it 

 varies considerably even during health. .It is best, with Wtinderlich, 

 to consider the increased secretion as disease or salivation, when it 

 ceases to pass into the stomach with the ingesta ; but some of it flows 

 out of the mouth, some is spit out, or is swallowed by itself, because 

 it becomes troublesome. 



ETIOLOGY. Physiology sufficiently explains the causes of most 

 forms of salivation ; in other cases we do not know them. 



Salivation is caused 1. By irritation of the mucous membrane of 

 the mouth or pharynx. Introduction of irritating substances into the 

 mouth excites the flow of saliva, which consequently occurs in most of 

 the affections of the mouth described in the preceding chapters, as 

 well as in almost all surgical affections of the mouth. According to 

 the beautiful experiments of I/udwig, the flow of saliva is increased 

 by irritation of certain nerves, such as the lingual branch of the tri- 

 facial or the glossopharyngeal ; this increase also occurs when these 

 nerves are divided and their central ends irritated. Of course the 

 irritation of the divided nerves must be transferred to the nerve fil- 

 aments governing the secretion of saliva, which is then to be regarded 

 as a reflex symptom. In the same way we may regard the flow of 

 saliva caused by the irritation of the peripheral expansions of the 

 glossopharyngeal and lingual nerves induced by acrid ingesta, by 

 wounds or ulcers, as a reflex symptom. Probably the salivation ob- 

 served in neuralgias of the trifacial results from the same cause. The 

 increase of saliva due to the use of mercurial and iodine preparations 

 appears to depend not on the simple addition of these substances to 

 the secretion, but to the irritation of the mouth, produced by excreting 

 them for a long time. For they must be long taken before the secre- 

 tion of sali va is greatly increased ; salivation does not begin till the 

 roouth becomes diseased from their continued action. Corresponding 



