Considered mineralogically, and now demonstrated beyond a doubt, coal and the diamond are found to be one and the same in substance, and nearly also in their modes of formation. Newton detected the properties of the diamond in its refractive power over the rays of light, and inferred that, like amber, it was an unctuous body crystallized. In the crucible he reduced it to a state of pure carbon, burning, volatilizing, and resulting in the same elementary products as charcoal. Liebig goes a step farther, and declares the diamond to be a crystalline residuum from decayed vegetables. The action of fire could not produce the mineral, but would rather have the effect of drawing out its inflammable tendencies. “Science,” he adds, “can point to no process capable of accounting for the origin and formation of diamonds, except that of decay. And there is the greatest reason for believing that they have been formed in a liquid.” Sir David Brewster, in his beautiful optical analysis, has arrived at the same general conclusions. Coal is also a product of vegetable decay, collected and formed in a liquid. It has not crystallized, and therefore wants the sparkle and the luster of the diamond. It retains all the carbon, and more of the hydrogen, and is in consequence infinitely more useful and valuable than even the precious gem. It is carefully incased and preserved among the rocks of the earth, and thereby in like manner akin to the glittering idol, whose true habitat has been found to be the sandstones[5] immediately overlying the carboniferous formation. Thus far the parallel can be traced between the two apparently very dissimilar and unequally prized minerals: in extent of substance and geographical distribution, the history of each stands apart.