MRS. B.
But you could not have it in a glass bottle, for in that case the acid would be saturated with silex, and incapable of executing an engraving; the same thing would happen were the acid kept in vessels of porcelain or earthen-ware; this acid must therefore be both prepared and preserved in vessels of silver.
If it be distilled from fluor spar and vitriolic acid, in silver or leaden vessels, the receiver being kept very cold during the distillation, it assumes the form of a dense fluid, and in that state is the most intensely corrosive substance known. This seems to be the acid combined with a little water. It may be called hydro-fluoric acid; and Sir H. Davy has been led, from some late experiments on the subject, to consider pure fluoric acid as a compound of a certain unknown principle, which he calls fluorine, with hydrogen.
Sir H. Davy has also attempted to decompose the fluoric acid by burning potassium in contact with it; but he has not yet been able by this or any other method, to obtain its basis in a distinct separate state.
We shall conclude our account of the acids with that of the MURIATIC ACID, which is perhaps the most curious and interesting of all of them. It is found in nature combined with soda, lime, and magnesia. Muriat of soda is the common sea-salt, and from this substance the acid is usually disengaged by means of the sulphuric acid. The natural state of the muriatic acid is that of an invisible permanent gas, at the common temperature of the atmosphere; but it has a remarkably strong attraction for water, and assumes the form of a whitish cloud whenever it meets any moisture to combine with. This acid is remarkable for its peculiar and very pungent smell, and possesses, in a powerful degree, most of the acid properties. Here is a bottle containing muriatic acid in a liquid state.
CAROLINE.
And how is it liquefied?
MRS. B.
By impregnating water with it; its strong attraction for water makes it very easy to obtain it in a liquid form. Now, if I open the phial, you may observe a kind of vapour rising from it, which is muriatic acid gas, of itself invisible, but made apparent by combining with the moisture of the atmosphere.
EMILY.