Yes, it does; it is of equal importance in the arts, and is even preferred to potash for some purposes; but you will not be able to distinguish their properties till we examine the compound salts which they form with acids; we must therefore leave soda for the present, and proceed to AMMONIA, or the VOLATILE ALKALI. EMILY. I long to hear something of this alkali; is it not of the same nature as hartshorn? MRS. B. Yes, it is, as you will see by-and-bye. This alkali is seldom found in nature in its pure state; it is most commonly extracted from a compound salt, called _sal ammoniac_, which was formerly imported from _Ammonia_, a region of Libya, from which both these salts and the alkali derive their names. The crystals contained in this bottle are specimens of this salt, which consists of a combination of ammonia and muriatic acid. CAROLINE. Then it should be called _muriat of ammonia_; for though I am ignorant what muriatic acid is, yet I know that its combination with ammonia cannot but be so called; and I am surprised to see sal ammoniac inscribed on the label. MRS. B. That is the name by which it has been so long known, that the modern chemists have not yet succeeded in banishing it altogether; and it is still sold under that name by druggists, though by scientific chemists it is more properly called muriat of ammonia. CAROLINE. Both the popular and the common name should be inscribed on labels--this would soon introduce the new nomenclature. EMILY. By what means can the ammonia be separated from the muriatic acid? MRS. B. By chemical attractions; but this operation is too complicated for you to understand, till you are better acquainted with the agency of affinities. EMILY. And when extracted from the salt, what kind of substance is ammonia? MRS. B. Its natural form, at the temperature of the atmosphere, when free from combination, is that of gas; and in this state it is called _ammoniacal gas_. But it mixes very readily with water, and can be thus obtained in a liquid form. CAROLINE. You said that ammonia was more complicated in its composition than the other alkalies; pray of what principles does it consist? MRS. B. It was discovered a few years since, by Berthollet, a celebrated French chemist, that it consisted of about one part of hydrogen to four parts of nitrogen. Having heated ammoniacal gas under a receiver, by causing the electrical spark to pass repeatedly through it, he found that it increased considerably in bulk, lost all its alkaline properties, and was actually converted into hydrogen and nitrogen gases; and from the latest and most accurate experiments, the proportions appear to be, one volume of nitrogen gas to three of hydrogen gas. CAROLINE. Ammonia, therefore, has not, like the two other alkalies, a metallic basis? MRS. B.