MRS. B.
Yes; there are many such salts, as, for instance, common salt, sulphat of magnesia, and a variety of others.
Sulphat of lime is very frequently met with in nature, and constitutes the well-known substance called gypsum, or plaster of Paris.
Sulphat of magnesia, commonly called Epsom salt, is another very bitter medicine, which is obtained from sea-water and from several springs, or may be prepared by the direct combination of its ingredients.
We have formerly mentioned sulphat of alumine as constituting the common alum; it is found in nature chiefly in the neighbourhood of volcanos, and is particularly useful in the arts, from its strong astringent qualities. It is chiefly employed by dyers and calico-printers, to fix colours; and is used also in the manufacture of some kinds of leather.
Sulphuric acid combines also with the metals.
CAROLINE.
One of these combinations, sulphat of iron, we are already well acquainted with.
MRS. B.
That is the most important metallic salt formed by sulphuric acid, and the only one that we shall here notice. It is of great use in the arts; and, in medicine, it affords a very valuable tonic: it is of this salt that most of those preparations called steel medicines are composed.