According to another account, the liming process consists in steeping for some weeks in a pit with lime-water. The object of it is to remove any blood or flesh adhering to the skin, and to form a soap with any fatty matters present. During the boiling, test-samples of the liquor are taken from the boiler at intervals and examined as to their consistence; when a sample in cooling forms a stiff jelly, the charge is ready to be drawn off. The first boiling generally occupies about 8 hours; and when a charge of liquor has been withdrawn, the boiler is replenished with fresh water, and the boiling is continued. The complete exhaustion of the gelatinous matter is only effected after 6 boilings, occupying about 48 hours. The successive charges deepen in colour till the last. The boiling must not be protracted beyond the point necessary for yielding a stiff gelatinous solution, otherwise the long-continued heat will have the effect of destroying the congealing power of the gelatine. Before passing to the coolers, the liquor is kept for some time in " settling-backs " in a fluid condition, to allow mechanical impurities to settle out. The coolers measure 6 ft. long, 2 ft. wide, and 1 ft. deep.

When the glue has set, a little water is run over its surface to facilitate its being cut into slices about 1 in. thick. The drying is the most delicate and difficult operation, and the characters of our climate have much to do with the inferior quality of the glue produced here as compared with that made in France. Simple air-drying affords the best article but the plastic masses must be protected from rain, frost, and strong dry heat - , hence spring and autumn are the most favourable seasons, when the drying may be effected in 12 to 18 days. The cutting of the glue into thin slices is performed by means of a wooden box with slits in it at suitable intervals, and a brass wire attached to a bow. The square blocks from the coolers are placed in these boxes, and thus held securely while being operated upon by the wire. The slices are spread on nets attached to wooden frames, which are placed in piles in a field, with proper intervals for the admission of air, and each pile is roofed over for protection from the weather. The slices are turned 2 or 3 times a day, and for this purpose the roof is lifted off the pile, and the uppermost frame is placed on the ground.

The slices are turned one by one, and then the second frame is lifted off and set on the first, and so on till a new pile is formed, when the roof is replaced.

During the drying, the glue is more likely to receive injury than at any other period. In very warm weather, the cakes are liable to become so soft as to lose all shape and unite with the frames, or they may even melt entirely aud flow away. A thunderstorm sometimes prevents a whole field of glue from hardening, while a thick fog may make it all mouldy. A brisk drying wind may harden it so suddenly as to render it unsightly and unfit for the market. A hard frost, by freezing the water in the glue, may cause it to crack in all directions, rendering remelting necessary. Thus the manufacture has many vicissitudes to suffer, and can only be profitably and conveniently carried on in temperate and equable weather. The drying, however, is not entirely finished in the open air. When the glue is about three parts dry, it is removed to lofts, where in the course of some weeks or months the hardening is completed. But as the surfaces of the cakes become mouldy and soiled, it is at length necessary to scour them with a scrubbing-brush and hot water, and set them up to drain.

They are then finally dried off in a stove-room at an elevated temperature, which, when they are once solid, only serves to harden and improve them.

To obviate the ill consequences of extremes of temperature and changes of weather in the manufacture of glue, Fleck proposes desiccation in the presence of certain salts. When a solution of gelatine is treated with ammonia sulphate, magnesia sulphate, or Glauber's salts, the gelatine contracts into an elastic mass no longer susceptible of fermentation, and containing but 18 per cent, of water. Mixed with fresh glue, which contains 80 or 90 per cent, of water, it makes a glue of medium consistency, easily soluble, containing 53.4 per cent, of water, and resembling that prepared for cloth-workers' use by Stalling of Dresden. Undried glue contains 72 to 93 per cent, of water; glue carefully dried in the air, 12 to 15 per cent. only. The problem is therefore to eliminate 60 to 80 per cent, of the water as speedily as possible without injury to the quality of the glue. If the bottom of a flat vessel be covered with a layer of the above-mentioned salts, and the sheet of glue laid thereon between 2 damp cloths, the salts quickly deliquesce. At the end of 12 or 18 hours, this ceases, and the sheets will be found to contain 25 per cent, of water only. Desiccation can thus be effected without the risks of melting and putrefaction in summer or congelation in winter.

The glue gains rather than loses in respect of adhesive powers. It, however, retains 3 to 6 per cent, of the salts employed, which; although they do not impair its quality, give it a dull appearance, like Russian glue. The salts can be dried by evaporation, and used over again. (Mon. Indust. Beige.)

It appears from the observations of Schattenmann, a glue-maker, that fresh glue dries much more readily than glue that has been once or twice melted; and that dry glue steeped in cold water absorbs different quantities of water according to the quality of the glue; and the proportion of water so absorbed may be used as test of the quality of the glue.

It seems that fresh glue contains water of composition, or water more intimately united with the glue than water mixed with it in the process of melting, which admits of being readily disengaged by evaporation. The combined water of dry glue disappears in the course of successive meltings and solidifications to which glue is subjected. Glue in thin plates is usually of better quality than thick ones, even when made with the same kind of gelatine, because the thin plates admit of a more complete drying than the thick. In applying Schattenmann's test, dry glue is immersed for 24 hours in water at the temperature of about 60° F. (15 1/2° C). A jelly will thus be formed, the qualities of which will fairly represent those of the glue. For example: the finest ordinary glue, or that made from white bones, absorbs 12 times its weight of water in 24 hours, so that a plate weighing 3 gr. produces 39 gr. of fine elastic jelly. Glue from dark bones absorbs 9 times its weight of water, and produces not quite so fine a jelly. The ordinary glue of Alsace or of Germany, made from animal refuse, absorbs 5 times its weight of water, producing a soft brown jelly, without elasticity and consistence, and falling to pieces when handled.