118 INSALIVATION. 



though a curious and interesting property, has no signifi- 

 cance as to its physiological function, since it does not take 

 place in the natural digestive process. We shall see here- 

 after that there are other means provided for the digestion 

 of starchy matters, altogether independent of the action of 

 the saliva." 



Viewing this question as a veterinarian, I must say that 

 I attribute far greater importance to the chemical changes 

 occurring during a slow mastication, with an abundant 

 secretion of the liquids of the mouth than Dr Dalton does. 

 It is of great moment in herbivorous animals, though the 

 mechanical use of the saliva is most important, and if the 

 two parotid ducts of a horse are simultaneously opened, the 

 animal will soon choke from the want of liquid to soften 

 the food. 



DISEASES OF THE SALIVAEY APPARATUS. The secretion 

 of saliva may be diminished, increased, or perverted. Its 

 diminution is observed in febrile diseases, and also in affec- 

 tions associated with a free discharge of water from the blood. 

 Its density then increases, and the mouth of the animal be- 

 comes hot and clammy. The saliva may be diminished in 

 quantity from disease of the glands, or closure of the ducts. 



Ptyalism, or excessive secretion of saliva, is not so common 

 in the lower animals as in man, in whom it has been frequently 

 witnessed, as the result f the administration of mercury. 

 Mercurial ptyalism is, however, seen, and especially in cattle, 

 from rubbing mercurial ointment on the skin for mange. It 

 has been seen in the horse from the internal exhibition of 

 calomel and opium, purposely to obtain salivation, and also 

 by rubbing the mercurial ointment over the parotidean region. 

 Severe salivation in the horse has been observed from this 

 animal having been forced to eat green food highly charged 

 with mustard, and this is a common cause of ptyalism also 



