COMPOUNDS OF ORGANIZATION. 61 



sidered as albumen in as pure a state as it has hitherto been 

 obtained. 



It is a colourless viscid fluid. When dried at a low tem- 

 perature, it loses four-fifths of its weight, and assumes the 

 appearance of dried gelatine, possessing, however, a greater 

 degree of transparency. 



It is readily soluble in cold water, and the solution 

 changes vegetable blues into green. When the solution is 

 heated to 165 Fahr. the albumen coagulates into a white 

 mass, of considerable consistence, which possesses peculiar 

 properties, to be taken notice of afterwards. When albu- 

 men is in a dried or coagulated state, it will continue un- 

 changed for a great length of time ; but, when in a liquid 

 state, it soon putrifies. During this process, silver is black- 

 ened when brought in contact with it, and the smell like- 

 wise indicates the presence of sulphuretted hydrogen. The 

 mineral acids, alcohol and ether, when poured into a solu- 

 tion of albumen, coagulate it, in same manner as heat. 

 The alkalies and earths produce no change. The metallic 

 salts likewise occasion copious precipitates. Dr BOSTOCK 

 found, that a drop of the saturated solution of oxymuriate 

 of mercury, falling into water containing y ^ <jth part of its 



weight of albumen, produced an evident milkiness. 



When a solution of tannin is poured into liquid albumen, 

 a copious yellow precipitate falls down, of the consistency 



of pitch, and insoluble in water ; which is formed by the 



union of the two substances. 



Coagulated Albumen was first examined with care by the 



celebrated HATCHETT * ; and several additions have been 



made to its history by LINK (. 



It is insoluble in water, unless when long exposed to its 



influence ; and, even then, only a small portion is taken up, 



* Phil. Trans. 1800. t Annals of Phil. vii. 456. 



