384 Analyses of Boohs. [May 



2. The quantity secreted depends upon the degree and 

 nature of the nervous stimulus. 



3. The secretive organs are excited by the mechanical 

 action of the mouth. 



4. The quantity of saliva which is separated from the 

 glands during eating and drinking is very great, and in- 

 creases with the hardness of the food. 



5. From the parotid in the 24 hours from 65 to 95 grms. 

 or from 2 oz. 6 drs to 3 oz. troy, of saliva are separated. 



6. Saliva from the mouth proceeding from five glands 

 amounts to six times the quantity from the parotid. The 

 saliva of the mouth, however, contains a considerable 

 quantity of mucus. 



7. The saliva during the excitement of mastication or 

 drinking is alkaline, at other times acid. 



8. The specific gravity varies from 1*0061 to 1*0088. 

 The causes which occasion these changes are not yet 

 ascertained. 



9. The results of analysis are similiar to those of Gmelin 

 and Berzelius, who found it to consist of salts and organic 

 matter. 



10. The organic constituents are salivary mucus ; a peculiar 

 salivary matter, with the characters which Berzelius has 

 described and extractive matter; a substance soluble in 

 alcohol of thesp.gr. 0*863, when the portion soluble in 

 absolute alcohol remains mixed with it, but insoluble, and 

 possessing the characters of salivary matter after that con- 

 stituent has been removed. 



Article VII. 



ANALYSES OF BOOKS. 



The Transactions of the Linnean Society of London. 

 Vol. xvii. Part I. 1834. 



Contents. — I. Description of the organs of voice in a new 

 species of wild swan (Cygnus Buccinator Richardson.) By W. 

 Yarrell, Esq., F. L. S., &c. 



II. Description of three British species of fresh water fishes be- 

 longing'to the genus Lenciscus of Klein, by W. Yarrell, Esq., 

 F. L. S., &c. 



III. Observations on the Tropaeolum pentaphyllum of Lamarck, 

 by Mr. David Don. 



