72 MASTICATION AND DEGLUTITION. 



mucous membranes are constantly shedding and renewing, like 

 the epidermis, from their ceils successively shrivelling ; and that 

 saliva taken before breakfast, and examined with the microscope, 

 presents such membranous particles, which are the animal matter 

 mentioned by chemists, and soluble only in hydrochloric (muriatic) 

 acid. He adds, that, besides muriate of soda, it contains muriate 

 of ammonia; and as to the lactates, he proves that lactic acid is 

 only a combination of albumen and acetic acid. The quantity of 

 ammonia, salts, and membranous particles varies, and is much 

 greater before breakfast. He considers the saliva to be an albu- 

 minous solution, mixed with membranous fragments and salts, 

 which affect its solubility in water/ 



" The saliva flows from three orders of conglomerate glands, 

 placed laterally and interiorly with respect to the lower jaw. 



" The parotids^ are the largest, -and pour forth the saliva behind 

 the middle molares of the upper jaw, through the Stenonian ducts : h 



" The submaxillary *, through the Whartonian : k 



" The sublingual l , the smallest, through the numerous Ri- 

 vinian. m 



a, parotid gland : b, parotid duct : 

 c, submaxillary gland : d, submax- 

 illary duct : e, sublingual gland. 



f 1. c., p. 454. sq. 



8 '* See De Courcelles, Icones Musculorum Capttis, tab. i. g. h." 



h " Stenonis, Observationes Anqtomic(, p. 20." 



1 " De Courcelles, 1. c. tab. n. 1. 1." 



* " Wharton, Adenographia, p. 12O." 



1 " De Courcelles, tab. v. g. g. g." 



ln " Rivinus, De Dyspepsia. Lips. 1 678. 4to. 



Aug. Fr. Walther, De Lingua Humana, ib. 1724. 4to." 



