usually thrown to the dogs; and as we cannot expect them to enter into
chemical considerations, it is in some degree excusable. Besides, it
requires a prodigious quantity of fuel to dissolve bones and obtain the
gelatine from them.

The solution of bones in water is greatly promoted by an accumulation of
heat. This may be effected by means of an extremely strong metallic
vessel, called _Papin's digester_, in which the bones and water are
enclosed, without any possibility of the steam making its escape. A heat
can thus be applied much superior to that of boiling water; and bones,
by this means, are completely reduced to a pulp. But the process still
consumes too much fuel to be generally adopted among the lower classes.

CAROLINE.

And why should not a manufacture be established for grinding or
macerating bones, or at least for reducing them to the state of
shavings, when I suppose they would dissolve as readily as hartshorn
shavings?

MRS. B.

They could not be collected clean for such a purpose, but they are not
lost, as they are used for making hartshorn and sal ammoniac; and such
is the superior science and industry of this country, that we now send
sal ammoniac to the Levant, though it originally came to us from Egypt.

EMILY.

When jelly is made of isinglass, does it leave no sediment?

MRS. B.

No; nor does it so much require clarifying, as it consists almost
entirely of pure gelantine, and any foreign matter that is mixed with
it, is thrown off during the boiling in the form of scum. --These are
processes which you may see performed in great perfection in the
culinary laboratory, by that very able and most useful chemist the cook.

CAROLINE.

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