18 SALIVA. 



extremely turbid from the presence of an enormous number 01 

 epithelial cells, which were not deposited when the fluid was allowed 

 to stand. The fluid had an alkaline reaction, and did not coagulate 

 on heating ; it left 0*999 of solid residue, in which were 0*385 

 parts of organic and 0*614 of inorganic matter. The insoluble 

 salts contained no carbonate of lime. 



Jacubowitsch collected the mucous secretion of the mouth by 

 tying Steno's and Wharton's ducts, keeping the animal's nostrils 

 open, and retaining the head in an inclined position, so that the 

 animal being unable to swallow, the mucus flowed from the mouth. 

 He collected the secretions of the parotid and submaxillary glands 

 by introducing a fine silver canula into their respective ducts. 



In addition to the above-mentioned differences in the indi- 

 vidual secretions of which the saliva of the dog is made up. 

 Jacubowitsch further notices that, (a) the parotid saliva, exposed to 

 the air, becomes rapidly covered with a film of crystals of carbo- 

 nate of lime, which is not the case with either of the other secre- 

 tions ; (b) that at a temperature of 100, the parotid saliva does 

 not become turbid, whilst the other secretions, at least in a slight 

 degree, become opaque ; (c) that the parotid saliva, if boiled with 

 nitric acid, and subsequently treated with ammonia, does not 

 assume the yellow or orange tint which is developed when the 

 secretions of the buccal mucous membrane and the submaxillary 

 glands are similarly treated; and (d) that it is only in parotid 

 saliva that carbonate of potash produces a slight precipitation of 

 carbonate of lime. 



Jacubowitsch has also analysed the mixed saliva of the dog, in 

 one instance with the exclusion of the parotid, and in another with 

 that of the submaxillary secretion. 



After this review of the chemical characters of the different 

 secretions constituting the saliva, we have little to add regarding 

 the composition of MIXED or ORDINARY SALIVA. 



In the ordinary saliva of man, Berzelius* found 0*7 1-J of solid 

 constituents, Tiedemann and Gmelinf 1'14 to 1'19, WrightJ 

 1*19, and L'Heritier 1'35-g-; Jacubowitsch found only 0'484-g- ; 

 Frerichs in 18 analyses, 0*51 to 1'05-g-; and, from numerous determi- 

 nations of filtered saliva, I have only found from 0*348 to 0'841; so 

 that the statements of the older observers are obviously too high. 



* Forelasningar i Diurkeimen. 2 vol. Stockholm, 1808. 



f Verdauung nach Versuchen, Bd. 1,8. 9 ff. 



J Op. cit. 



$ Cliimie pathol. p. 290. Paris, 1842. 



