Enough has been given in this chapter to permit of the intelligent and thoughtful at once following us, in the manufacture and finish of—we will say for example—buttons. The mass in a tough but plastic state, a toughness and plasticity in combination with which there exists no approachable parallel—having been so rendered by simply plunging it into boiling water, becomes of as easy manipulation as clay. Indeed the material in this stage being so like clay, we can scarcely point to any better illustration than the porcelain button manufacture, which being familiar to most, there can be no need to detail. Treated thus like clay, the moulds may be filled by the gross, and the buttons afterwards submitted to vulcanization. The moulds may bear any impress, and however fine such patterns may be, the material will receive and retain them after vulcanization, to a degree which will defy every power that destroys all other substances short of those of actual cutting, filing, or grinding. Thus a button is produced at an extraordinary economical rate, and with marvellous ease, which, while comparing the facility of its origin to that of the porcelain, possesses the superlative qualities of being comparable with one made with the properties and strength of iron or other metal, and in imitation of bronze, ivory, cameo, and is, indeed, a substitute for any other, and the very best material or thing ever used for button making. In a word, it may possess the closest similitude to the most exquisite carving, with the properties of bronze, ivory, or any hard and scarce material. The applications as far as results are concerned, are attended with like favorable characteristics, whether the article produced be nearly every one of those innumerable and familiar things, which meet us at each turn, either within the palace or cottage, or the many others to be met with out of doors. CHAPTER IV. VULCANIZATION.