62 PHILOSOPHY OF ZOOLOGY. 



in a state in which it appears incapable of combining with 

 tannin. 



It is likewise insoluble in alcohol ; but, when that liquid 

 is allowed to stand upon it, or to be boiled along with it, it 

 becomes muddy. With sulphuric acid, a brownish-yellow 

 solution is obtained, from which the albumen is precipitated 

 by the addition of water. Nitric and muriatic acids, when 

 assisted by heat, likewise dissolve it ; the former changing 

 it into gelatine. Acetic acid has no effect upon it, either 

 hot or cold. 



Caustic soda and potash dissolve albumen, when assist- 

 ed by heat, and form compounds resembling soap. Am- 

 monia produces no effect upon it. 



It is considered as consisting of carbon, hydrogen, azote, 

 and oxygen, (the azote in greater quantity than in gelatine,) 

 with traces of soda and sulphur. 



Albumen exists in great abundance, both in a coagulated 

 and liquid state, in the different parts of animals. Hair, 

 nails, and horn are composed of it. It appears likewise as 

 a constituent of bone and shells ; and there are few of the 

 fluid or soft parts of animals, in which it does not exist in 

 abundance. What has hitherto been termed the Resin of 

 Bile, is, according to BERZELIUS, analogous to albumen. 



Albumen is extensively used in the arts. When spread 

 thin on any body, it soon dries, and forms a coating of var- 

 nish. Its adhesive power is likewise considerable. When 

 rubbed on leather, it encreases its suppleness. But its chief 

 use is in clarifying liquors. For this purpose, any substance 

 abounding in albumen, as the white of eggs, or the serum of 

 blood, is mixed with the liquid, and the whole heated to 

 near the boiling point. The albumen coagulates, and falls 

 to the bottom, carrying along with it the impurities which 

 were suspended in the fluid, and which rendered it muddy. 

 If the liquor contains alcohol, the application of heat is un- 

 necessary. 



