The congealing boxes are of wood. and are nearly square, being slightly narrower at the bottom than the top; they are filled to the brim, and when their content's are suf ficiently solidified, the glue, with a little management, turns out in the form of a cube, which is cult into thin slices by a wire in the same manner as soap; and these larger slices are subdivided .Into stwiller cakes by a wet knife: Frames, with nets stretched upon are provided for dryitig the cakes upon; and these frames, when covered with the cakes of glue, are adjusted oneover another at a little distance apart, supported between four uprights, and if in the open air, covered over with little wooden roofs, the whole being arranged so that the air can have free access to.facilitate drying. This pro cess is an anxious one,to the manufacturer, as the changes of the weather have great and often completely destructive effects upon glue in this state; and in this country only the spring and the autumn can be relied upon. with any satisfaction. Generally, after the open-air drying, the glue is taken to drying-rooms heated slightly, where it hardens effectually; but it is not yet finished; the cakes at this stage have a.dull, unsightly look,
to remedy which they are dipped into cold water, or are wetted with a brush dipped in hot water, and redried, this wetting giving the cakes a bright varnished appearance. Great Britain does not excel in the manufacture of glue, and British workmen usually prefer the dark variety. Very superior glue is made by the Dutch and Germans,•by whom the light and more carefully made varieties are most prized, the adhesive qualities being lessened in proportion to the impurities present in the material.
Besides its use in joinery, cabinet-making, and similar operations, glue is used by paper-makers and in dressing silks; and for these last two purposes fine light-colored finds in thin cakes are made. Large quantities are employed also by paper-hangers and others for sizing walls in the state called size, which is the glue simply gelatinized after boiling in the first process. A very fine and pure white size is made by the bonnet makers of Bedfordshire and other places of the skins of calves' head, ears, and the. under part of the neck and belly: this is used for stiffening straw, cotton, horse-hair, and other plaits for making bonnets and hats.