d that is used to purify sugar does
not remain in it; it would be a disgusting idea. I have heard of some
improvements by the late Mr. Howard, in the process of refining sugar.
Pray what are they?

MRS. B.

It would be much too long to give you an account of the process in
detail. But the principal improvement relates to the mode of evaporating
the syrup, in order to bring it to the consistency of sugar. Instead of
boiling the syrup in a large copper, over a strong fire, Mr. Howard
carries off the water by means of a large air-pump, in a way similar to
that used in Mr. Leslie's experiment for freezing water by evaporation;
that is, the syrup being exposed to a vacuum, the water evaporates
quickly, with no greater heat than that of a little steam, which is
introduced round the boiler. The air-pump is of course of large
dimensions, and is worked by a steam engine. A great saving is thus
obtained, and a striking instance afforded of the power of science in
suggesting useful economical improvements.

EMILY.

And pray how is sugar-candy and barley-sugar prepared?

MRS. B.

Candied sugar is nothing more than the regular crystals, obtained by
slow evaporation from a solution of sugar. Barley-sugar is sugar melted
by heat, and afterwards cooled in moulds of a spiral form.

Sugar may be decomposed by a red heat, and, like all other vegetable
substances, resolved into carbonic acid and hydrogen. The formation and
the decomposition of sugar afford many very interesting particulars,
which we shall fully examine, after having gone through the other
materials of vegetables. We shall find that there is reason to suppose
that sugar is not, like the other materials, secreted from the sap by
appropriate organs; but that it is formed by a peculiar process with
which you are not yet acquainted.

CAROLINE.

Pray, is not honey of the same nature as sugar?

MRS. B.

Honey is a mixture of saccharine matter and gum.

EMILY.

I thought that honey was in some measure an animal substance, as it is
prepared by the bees.

MRS. B.

It is rather collected by them from flowers, and conveyed to their
store-houses, the hives. It is the wax only that undergoes a real
alteration in the body of the bee, and is thence converted into an
animal substance.

Manna is another kind of sugar, which is united with a nauseous
extractive matter, to which it owes its peculiar taste and colour. It
exudes like gum from various trees in hot climate