26 SALIVA. 



phosphate of soda : hence it is invariably necessary to determine 

 the nature of the free acid, whenever it is present in the saliva, in 

 different diseases, before we venture to decide regarding the course 

 of the chemical process accompanying the disease ; it is, however, 

 the chief aim of all chemical investigations of animal objects, to 

 draw from them a conclusion regarding the nature of the chemical 

 process in the healthy or diseased state. For semeiotics the simple 

 statement suffices that in this or that condition the saliva exhibits 

 an acid reaction. We shall now briefly mention those pathological 

 states in which, as yet, the saliva has been found to present an 

 acid reaction. 



The saliva is acid, according to Donne,* in inflammatory 

 affections of the primce vice, in pleuritis, encephalitis, acute rheu- 

 matism, intermittent fever, and uterine affections, and, according 

 to L'Heritier, also in cancer of the stomach. Wright assumes 

 that there are four varieties of acid saliva, namely, (a) that which 

 occurs in idiopathic affections of the salivary glands; (b) that 

 which presents itself when there is a predominance of acid in the 

 organism generally, from constitutional or other causes, amongst 

 which he mentions scrofula, phthisis, rachitis, amenorrhcea, inflam- 

 matory rheumatism, &c.; (c) the form occurring in sub-acute 

 inflammation of the mucous membrane of the stomach and intes- 

 tines ; and (d) the form presenting itself in dyspepsia (a somewhat 

 vague mode of expression). In affections of the nervous system, the 

 saliva is on the other hand never acid, but often very strongly alka- 

 line. In catarrhal affections of the gastric and intestinal mucous 

 membranes and in the round perforating form of ulceration of the 

 stomach, I have very often, but not invariably, found the saliva 

 acid ; in cancer of the stomach and in diabetes, I have, however, 

 always found it acid. In inflammatory affections of the thoracic 

 organs, in acute rheumatism, typhus, &c., If have very often found 

 the saliva alkaline or perfectly neutral. According to Donne and 

 FrerichsJ the acid reaction always depends on the buccal mucous 

 membrane, which, when in a state of abnormal irritation, invariably 

 yields an acid secretion. 



Amongst the difficulties which usually present themselves in 

 the investigation of morbid saliva, we may notice that we can 

 rarely obtain a quantity sufficient for analysis, seeing that it is a 

 fluid which contains only a very small amount of solid constituents. 



* Histoire physiol. et pathol. de la Salive. Paris, 1836. 

 t Schmidt's Jahrb. Bd. 36, S. 185. 

 J Op. cit. p. 761. 



