1816.] Comparison of Allumen with Gluten. 457 
6. Acetic acid (acetum conceniratum of the Prussian Pharma- 
copeeia) does not dissolve albumen, even when boiled upon it. 
Nor is gluten dissolved by the same acid in similar cireum- 
stances. 
7. Caustie soda acts upon albumen, and forms a yellowish solu- 
tion. But the application of heat is requisite in order to obtain a 
complete solution. It is brownish-yellow, and transparent; and 
when saturated with an acid, it lets fall a white precipitate similar 
to albumen. When poured into alcohol, a white matter falls, mixed 
with carbonate of soda. On cooling, the solution lets fall a dark 
brown matter. 
Caustic soda likewise dissolves gluten, and the solution is yellow. 
But heat is requisite in order to obtain a complete solution. | It is 
brownish-yellow, and somewhat muddy.. When dropped. in 
alcohol, a yellowish-grey matter precipitates, containing carbonate 
of soda. Acids, likewise, throw down a_ yellowish-grey matter, 
When the solution cools, a yellowish matter subsides. 
8. Ammonia does not dissolve albumen, even when boiled on it. 
But it became whiter, more transparent, and bulky. 
Gluten was not dissolved, though boiled in ammonia;. but it 
became whiter, and fell to pieces. 
9. Albumen, when distilled, gave out ammonia and an empy- 
reumatic oil. When heated with potash, the smell of ammonia 
was not perceptible. 
Gluten likewise furnished ammonia and an empyreumatic oil, 
when distilled; nor did it give out the smell of ammonia when 
heated with potash. . 
From these experiments it is obvious that gluten and coagulated 
albumen do not differ much from each other. Gluten, with nitric 
acid and soda, forms muddy solutions ; albumen, transparent ones. 
Gluten forms with strong sulphuric acid a dark brown solution, 
with a shade of blood-red. Albumen forms a solution which has a 
yellowish-brown colour. Sulphate of albumen precipitates some 
metals white. Sulphate of gluten throws them down brown. ‘The 
former is precipitated by water, white; the latter, grey. Gluten 
gives more oxalic acid than albumen, when treated with nitric 
acid. The two substances do not differ so much from each other as 
different varieties of resin or gum. I think, therefore, that both 
should be placed under the same genus, Albumen occurs in many 
animal bodies in a coagulated state, while in others it is liquid. 
The same remarks apply to the state in which gluten occurs in 
vegetables. 
} now separated a quantity of vegetable albumen from the sap of 
white cabbage (wezsskohls). This sap let fall a green precipitate, 
which possessed the properties of the green matter of vegetables. 
When treated with alcohol, a grey flocky substance remained undis- 
solved, very similar to albumen prepared by boiling. ‘The filtered 
sap became muddy in the air; and, when boiled, deposited a grey 
matter in flocks. Water did not dissolve this matter, but became 
Vor. VII, N° VI, 2G 
