gh all bodies, like those of gravitation and
heat.

Secondly, The two electric ethers rush into combination, when they can
approach each other, after having been separated and condensed, and
produce a violent explosion emitting the heat and light, which were
previously combined with them; whereas the two magnetic ethers slowly
combine, after having been separated and accumulated on the opposite
ends of a soft iron bar, and without emitting heat and light produce a
neutral mixture, which, like the electric combination, ceases to be
cognizable by our senses or experiments.

Thirdly, The wonderful property of the magnetic ethers, when
separately accumulated on the ends of a needle, endeavouring to
approach the two opposite poles of the earth; nothing similar to which
has been observed in the electric ethers.

From these strict analogies between electricity and magnetism, we may
conclude that the latter consists of two ethers as well as the former;
and that they both, when separated by art or nature, combine by
chemical affinity when they approach, the one exploding, and then
consisting of a residuum after having emitted heat and light; and the
other producing simply a neutralised fluid by their union.

XI. _Conclusion._

1. When two fluids are diffused together without undergoing any change
of their chemical properties, they are said simply to be mixed, and
not combined; as milk and water when poured together, or as oxygen and
azote in the common atmosphere. So when salt or sugar is diffused in
water, it is termed solution, and not combination; as no change of
their chemical properties succeeds.

But when an acid is mixed with a pure alcali a combination is
produced, and the mixture is said to become neutral, as it does not
possess the chemical properties which either of the two ingredients
possessed in their separate state, and is therefore similar to neither
of them. But when a carbonated alcali, as mild salt of tartar, is
mixed with a mineral acid, they presently combine as above, but now
the carbonic acid flies forcibly away in the form of gas; this,
therefore, may be termed a kind of explosion, but cannot properly be
so called, as the ethereal fluids of heat and light are not
principally emitted, but an aerial one or gas; which may probably
acquire a small quantity of heat from the combining matters.

But when strong acid of nitre is poured upon charcoal in fine powder,
or upon oil of cloves, a violent expl