506- LIQUID PARTS OF ANIMALS. 



It had a slight colour/ doubtless, from an admixture of a little 

 blood. Its consistence is thready, like that of a decoction of lint- 

 seed, feel soft, taste slight, but saline. On standing a few hours 

 it deposits white filaments, "apparently of fibrin, (6 ounces depo- 

 sited only 1 grain.) But it amounted to only yjV&tf 1 of the sy- 

 novia. He found its constituents similar to those of the synovia 

 of the ox. Vauquelin conceives, that, besides albumen, it con- 

 tains a peculiar substance, neither coagulable by heat nor acids, 

 but capable of being precipitated by tannin. He found also so- 

 da, chloride of sodium, and chloride of potassium, but could not 

 discover any alkaline phosphates, 



5. Mr Brande, in the year 1809, made some experiments on 

 the synovia of the shark (Squalus maximus.}* In these fish 

 there exist in the vertebrae a peculiar synovia, which fills the ca- 

 vities between each. Mr Brande found this synovia of the speci- 

 fic gravity 1'027. It had the smell of fish oil. It did not mix 

 with water till the action was assisted by heat. The solution was 

 neither precipitated by boiling, nor by alcohol, nor by tannin. 

 It contains in solution a substance approaching to mucus by its 

 properties ; but which, in certain circumstances, is transformed 

 into a modification of gelatin and albumen. It is probably a 

 substance sui generis. 



Such is the imperfect collection of chemical facts hitherto as- 

 certained respecting synovia. We do not know as yet whether 

 it contains any peculiar animal principle, though such an opi- 

 nion is at least probable. 



CHAPTER XV. 



OF MUCUS. 



THE word mucus in the Latin language signifies properly the 

 gelatinous looking matter secreted in the nose, to defend it from 

 the action of the air that passes through it, and vulgarly called 

 snot. But in chemistry, it is used to denote the slimy transpa- 

 rent matter, which lines all the cavities of the body through which 

 foreign matters pass, in order to protect the internal surface of 



* Phil. Trans. 1809, p. 184. 



