To what an immense variety of purposes chemistry is subservient! EMILY. It appears, in that respect, to have an advantage over most other arts and sciences; for these, very often, have a tendency to confine the imagination to their own particular object, whilst the pursuit of chemistry is so extensive and diversified, that it inspires a general curiosity, and a desire of enquiring into the nature of every object. CAROLINE. I suppose that soup is likewise composed of gelatine; for, when cold, it often assumes the consistence of jelly? MRS. B. Not entirely; for though soups generally contain a quantity of gelatine, the most essential ingredient is a mucous or extractive matter, a peculiar animal substance, very soluble in water, which has a strong taste, and is more nourishing than gelatine. The various kinds of portable soup consist of this extractive matter in a dry state, which, in order to be made into soup, requires only to be dissolved in water. Gelatine, in its solid state, is a semiductile transparent substance, without either taste or smell. --When exposed to heat, in contact with air and water, it first swells, then fuses, and finally burns. You may have seen the first part of this operation performed in the carpenter’s glue-pot. CAROLINE. But you said that gelatine had no smell, and glue has a very disagreeable one. 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. True; but you must observe that leather can be produced only by gelatine in a membranous state; for though pure gelatine and tannin will produce a substance chemically similar to leather, yet the texture of the skin is requisite to make it answer the useful purposes of that substance.