MRS. B.
Glue is not pure gelatine; as it is not designed for eating, it is prepared without attending to the state of the ingredients, which are more or less contaminated by particles that have become putrid.
Gelatine may be precipitated from its solution in water by alcohol.—We shall try this experiment with a glass of warm jelly.—You see that the gelatine subsides by the union of the alcohol and the water.
EMILY.
How is it, then, that jelly is flavoured with wine, without producing any precipitation?
MRS. B.
Because the alcohol contained in wine is already combined with water, and other ingredients, and is therefore not at liberty to act upon the jelly as when in its separate state. Gelatine is soluble both in acids and in alkalies; the former, you know, are frequently used to season jellies.
CAROLINE.
Among the combinations of gelatine we must not forget one which you formerly mentioned; that with tannin, to form leather.
MRS. B.