mall number of simple
elements, or at least of such as have not hitherto been susceptible of
decomposition, by means of combination with oxygen; these are azote,
sulphur, phosphorus, charcoal, hydrogen, and the muriatic radical[30].
We may justly admire the simplicity of the means employed by nature to
multiply qualities and forms, whether by combining three or four
acidifiable bases in different proportions, or by altering the dose of
oxygen employed for oxydating or acidifying them. We shall find the
means no less simple and diversified, and as abundantly productive of
forms and qualities, in the order of bodies we are now about to treat
of.

Acidifiable substances, by combining with oxygen, and their consequent
conversion into acids, acquire great susceptibility of farther
combination; they become capable of uniting with earthy and metallic
bodies, by which means neutral salts are formed. Acids may therefore be
considered as true _salifying_ principles, and the substances with which
they unite to form neutral salts may be called _salifiable_ bases: The
nature of the union which these two principles form with each other is
meant as the subject of the present chapter.

This view of the acids prevents me from considering them as salts,
though they are possessed of many of the principal properties of saline
bodies, as solubility in water, &c. I have already observed that they
are the result of a first order of combination, being composed of two
simple elements, or at least of elements which act as if they were
simple, and we may therefore rank them, to use the language of Stahl, in
the order of _mixts_. The neutral salts, on the contrary, are of a
secondary order of combination, being formed by the union of two _mixts_
with each other, and may therefore be termed _compounds_. Hence I shall
not arrange the alkalies[31] or earths in the class of salts, to which
I allot only such as are composed of an oxygenated substance united to
a base.

I have already enlarged sufficiently upon the formation of acids in the
preceding chapter, and shall not add any thing farther upon that
subject; but having as yet given no account of the salifiable bases
which are capable of uniting with them to form neutral salts, I mean, in
this chapter, to give an account of the nature and origin of each of
these bases. These are potash, soda, ammoniac, lime, magnesia, barytes,
argill[32], and all the metallic bodies.

Sec. 1. _Of Potash._