224 OP MASTICATION AND DEGLUTITION. 



with an epithelium analogous to cuticle, (176) and is 

 lubricated by a very smooth mucus. 



350. This canal receives the approaching draught or 

 bolus of food, contracts upon it, propels it down- 

 wards, and, in the case of the bolus, stuffs it down, 

 as it were, till it passes the diaphragm and enters the 

 stomach. 



NOTES. 



(A) Saliva is composed of 



Water 



A peculiar animal matter 

 Mucus - 



Alkaline muriates - 

 « Lactate of soda and animal matter 

 Pure soda - 



What Berzelius calls mucus, Professor Thomson and l)r. Bos- 

 tock regard as albumen. It is insoluble in water, and when 

 ineinerated, but not before, yields a large portion of phosphate 

 of lime. The tartar of the teeth arises from its gradual decom- 

 position upon them, and consists of 



Earthy phosphates - - - - 79 . O 



Undecomposed mucus - - - 12 . 5 



Peculiar salivary matter - - - 1.0 



Animal matter soluble in muriatic acid 7 • 5 



6oo . Of 





(B) The glottis, when sound, may be sufficiently closed inde- 

 pendently of the epiglottis. M.Majendie sa*v two persons perfectly 

 destitute of epiglottis who always swallowed without difficulty. — 

 Pricis Eltmentaire, T. ii. p. 63. 



• J. Bcraclius, Mtdico-Chirurgical Trantactions. Vol. iii. p 242. 

 T Borzclius. 



