R. McCafferty, of Lancaster, Pa., patented a new process for this purpose on the 14th of April, 1857. It consists in putting half a pound of black gum catechu in a boiler of 100-horse power, until the water becomes the color of pale brandy, and during the week the water is kept as nearly that color as possible, by adding small pieces of catechu from time to time. So long as this color is kept up, no incrustation forms ; and in boilers where there is already an incrustation, its application gradually decomposes the lime, and it falls down, and is deposited in a kind of slush at the bottom, which may easily be washed away through the blow-off cock.