THE SALIVARY GLANDS SPECIFICALLY EXCITABLE. (17 



a certain degree neutralised, while other corroding .substances may be 

 simply diluted, and by mere reduction of concentration have their 

 harm fulness diminished. 



In the second place, when the injurious substances have to be wholly 

 removed, the saliva plays the rule of a washing-out fluid ; otherwise the 

 material, by clinging to the mucous membrane of the mouth, might in 

 longer or shorter time gain entry into the blood and there develop its 

 noxious influence. This last function of the fluid is hardly taken into 

 account at all in physiology, and yet it i-i evident that the saliva, as a 

 cleansing fluid, must have a wide importance. If you only think of 

 how often we are impelled to expectorate, that is, to wash out the 

 mouth with s diva after something unpleasant, this will be clear. Such 

 a view finds additional support when we reflect, that a feeling of dis- 

 gust prod u ( s almost as strong a flow of saliva as the sight of a tasty 

 meal. In both ca3e^ the secretion performs the oflice of forerunner: 

 in the first it prepares for the washing out of the mouth, in the second 

 for the requisite elaboration of the food. Think how often, when 

 something disagreeable enters the mouth, with what rapidity the siliva 

 is poured out, even after the unpleasant substance has been for a con- 

 siderable time removed, and not a trace more is apparent to the sense of 

 taste. Indeed, long afterwards one has only to recall the circumstances 

 to mind in order to bring on anew the secretion of saliva. Apparently 

 the psychic excitation of the nerves of salivary secretion also ushers 

 in the act of vomiting, which, as is well known, can be called forth 

 by mental influence. Further, the function of the saliva just men- 

 tioned is probably the true physiological explanation of the feeling 

 of disgust which many persons experience at the sight of the secretion 

 itself. 



Hence I hold that substances which obtain entry to the mouth set 

 up a secretion of saliva only because we have here the seat of a definite 

 physiological sense, and not because the peripheral terminations of 

 the buccal nerves are devoid of specific excitability, and capable of 

 being thrown into action by every desired form of stimulus. In other 

 words, the specific excitability of the peripheral endings of the salivary 

 nerves is very comprehensive and widely extended. This is no picture 

 of the imagination, for it can be supported by facts. To say nothing 

 of the testimony of earlier authors, that the salivary glands have 

 each particular exciting agencies to which they specially respond, we 

 can demonstrate the following facts from the material collected in our 

 laboratory. 



Dr. Glinski isolated the orifices of the salivary glands in dogs with 

 portions of the adjoining mucous membrane, brought them out of the 

 oral cavity, and caused them to heal into the edges of the skin wounds. 



