though the planets were composed of matter subject to the law of gravitation, the matter might still be so very dissimilar, that we might not be entitled to say that they belong to the same family as the earth. These meteoric bodies, however, tell us that this is not the case,—that the chemical elements are the same in the celestial and terrestrial spaces. About a third of the simple elements of chemistry have been found in meteoric stones; and what is still more to the point, no new element has been detected. There are chemical arrangements peculiar to meteorolites, but there is no element which has not been previously known in our terrestrial chemistry. It might, however, be argued that these stones are not fair specimens of planetary matter, and that to produce complete conviction, we must analyse the matter of each heavenly body, before we can found upon it an argument for the plurality of worlds. Science has met even this hard requirement, and the art of analysing the heavenly bodies is now practised. M. Bunsen has begun upon the sun, and he has detected, as we have seen, metals familiar to us on our globe. Iron, which plays so important a part in the structure of our globe, and in the industrial arts of man, holds a conspicuous place in the sun. This is only the first step. In all probability we shall soon have our knowledge of celestial chemistry greatly enlarged; and there is little doubt,
