The Birmingham people brown their barrels of inferior quality in the following way, to make them look equal to the best. They dissolve as much muriate of mercury as can be taken up in a dram-glassful of spirits of wine; this solution is mixed with one pint of water, or as much diluted as the person requires. A small quantity of the mixture is poured on a little whitening, and laid on the barrel with a sponge, rather lightly; as soon as dry, it is brushed off, and a fresh coat is laid on; and so on until the barrel is dark enough, which is generally about two days. The effect that the mercury has on every one of the joints of the fibres is wonderful: it never fails to make them, in two or three days at most, a beautiful brown; while the other parts, being harder, remain, comparatively speaking, quite light. The rust is killed by hot water, but after that, the barrels are suddenly immersed in cold water; which has the effect of heightening the brightness of both the colours. The appearance is beautiful, and equally as fine to the eye as stub-barrels browned in the same way; though this process is mostly used for the charcoal iron and the threepenny iron barrels. The only method in which there is no deception, is the smoke brown or stain; and, plainly speaking, this and no other is the reason the gun-makers condemn it. As the acid is decidedly weaker, and of course less liable to impart injury to the iron, no barrel can be browned by it, to look well and fine, but the best; or, in other words, none save those possessing steel in their composition.