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 1s 
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 3,1; 5th 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 Harcurrr *; and several additions have been 
made to its history by Linx +. 
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. + Annals of Phil, vii. 456. 
