OF MASTICATION AND DEGLUTITION. 221 



342. The saliva flows from three orders of conglome- 

 rate glands, placed laterally and interiorally with respect 

 to the lower jaw. 



The principal are the parotids* which pour forth 

 the saliva behind the middle molares of the upper jaw, 

 through the Stenonian ducts, f 

 The submaxillary ,% through the Whartonian.§ 

 The sublingual, || — the smallest, through the numerous 

 Rivinian.** 



343. The excretion of saliva, amounting, according 

 to the arbitrary statement of Nuck,ff to a pound in 

 twelve hours, is augmented by stimuli and by mecha- 

 nical pressure, or, if the expression may be allowed, 

 emulsion. 



The latter cause, greatly favoured by the situation 

 of the parotids, at the articulation of the jaws, occurs 

 when we chew hard substances, which thus become 

 softened. 



The former occurs when acrid substances are taken 

 into the mouth, which are thus properly diluted ; or 

 arises from imagination, (288) as when the mouth waters 

 during the desire for food. 



344. The mucus of the labial and buccal glands %% 

 and of the tongue, as well as the moisture which trans- 



* De Courcelle, Iconcs Musculorum Capitis. Tab. I. g. h. 



f Stenonis, Observationes Anatomical, p. 20. 



X De Courcelles, 1. c. Tab. n. 1. 1. 



§ Wharton, Adenographia. p. 120. 



|| De Courcelle, tab. v. g. g. g. 



** Rivinus, De Dyspepsia. Lips. 1678. -lto. 



Aug. Fr.Walther, De Lingua Humana, fb. 17/24. lto. 



ft Nuck, Sialographia. p. 29 sq. 



XX Do Courcelles, 1. C. Tab. iv. e. e. e. 



