212 OF THE SALIVA SECT. XXIV. i. 



\ SECT- XXIV. 



OF THE SECRETION OF SALIVA, AND OF TEARS, AND OF THE 

 LACRYMAL SACK. 



I. Secretion of faliva increafed by mercury in the blood, i. By the 

 food in the mouth. Drynefs of the mouth not from a deficiency of 

 faliva. 2. By fenfitive ideas. 3. By volition. 4. By diftafte- 

 ful fubftances . It isfecreted in a dilute and f aline Jlate. It then 

 becomes msre vifcid. 5. By ideas of diftafteful fubftances. 6. 

 By naufea. 7. By aver/ton. 8. By catenation nvith /Simulating 

 Jlubftances in the ear. II. I . Secretion of tears lefs in Jleep. 

 From J^imulation of their excretory duel. 2. Lacrymal fack is a 

 gland. 3. Its ufes. 4. Tears are fecreted % when the nafal duel 

 is jlimulated. 5. Or <w hen it is excited by fenfation. 6. Or by 

 volition. 7. The lacrymal fack can regurgitate its contents into 

 the eye. 8. More tears are fecreted by ajjbciation 'with the irri- 

 tation of the nafal duel of the lacrymal fack , than the puncla lacry- 

 malia can imbibe. Of the gout in the liver andjlomach. 



I. THE falival glands drink up a certain fluid from the cir- 

 cumfluent blood, and pour it into the mouth. They are fome- 

 times ftimulated into aftion by the blood, that furrounds their 

 origin, or by fome part of that heterogeneous fluid : for when 

 mercurial falts, or oxydes, are mixed with the blood, the ftim- 

 ulate thefe glands into unnatural exertions j and then an unufual 

 quantity of faliva is feparated. 



1. As the faliva fecreted by thefe glands is mod wanted during 

 the maftication of our food, it happens, when the terminations 

 of their dudls in the mouth are ftimulated into aftion, the fali- 

 val glands themfelves are brought into increafed aHon at the 

 fame time by aflbciation, and feparate a greater quantity of their 

 juices from the blood j in the fame manner as tears are produ- 

 ced in greater abundance during the ftimulus of the vapour of 

 onions, or of any other acrid material in the eye. 



The faliva is thus naturally poured into the mouth only du- 

 ring the ftimulus of our food in maftication ; for when there is 

 too great an exhalation of the mucilaginous fecretion from the 

 membranes, which line the mouth, or too great an abforption of 

 it, the mouth becomes dry, though there is no deficiency in the 

 quantity of faliva ; as in thofe who fleep with their mouths 

 open, and in fome fevers. 



2. Though during the maftication of our natural food the fa- 

 lival glands are excited into aftion by the ftimulus on their ex- 

 cretory 



