peroxide, unless we admit the existence of half-atoms. We have only spoken of three of the elementary bodies, as we wished our remarks to be as simple as possible; each of the sixty-three elements has, however, a definite combining proportion or atomic weight.
How admirably this atomic theory explains the laws of chemical combination; how intelligible it renders those fixed, invariable weights in which the elements unite to form compounds. All is shown to depend on the properties with which those inconceivably small particles of matter are invested.
We have told the reader all we know about atoms (at least all we think we know, for we can never be certain that atoms exist). They are immeasurably minute; they are separated from each other by wide intervals, and they have a definite weight.
A German chemist has endeavoured to render the atomic theory intelligible by a very ingenious illustration. He compares atoms to the heavenly bodies, which, in comparison with the extent of the space in which they are suspended, are infinitely small: that is, are atoms. Innumerable suns, with their planets and attendant satellites, move in infinite space, at definite and measured distances from each other. They are individually indivisible, inasmuch as there exists no force capable of separating them into parts,
