among artificers, a tenacious viscid matter, which serves as a cement to bind or connect things together.

Glues are of different kinds, according to the various uses they are designed for, as the common glue, glove-glue, and parchment-glue; whereof the two last are more properly called size.

The common or strong glue is chiefly used by carpenters, joiners, cabinet-makers, &c. It is made of skins of animals, as oxen, cows, calves, sheep, &c.; and the older the creature is, the better is the glue made of its hide. Indeed whole skins are but rarely used for this purpose, but only the shavings, parings, or scraps of them; or the feet-finews, &c. That made of whole skins, however, is undoubtedly the best; as that made of finews is the very worst.

The Method of Making Glue. In making glue of parings, they first steep them two or three days in water; then, washing them well out, they boil them to the consistence of a thick jelly; which they pass, while hot, through ozier-baskets, to separate the impurities from it; and then let it stand some time, to purify it further: when all the filth and ordure are settled to the bottom of the vessel, they melt and boil it a second time. They next pour it into flat frames or moulds; whence it is taken out pretty hard and solid, and cut into square pieces or cakes. They afterwards dry it in the wind, in a fort of coarse net; and at last string it, to finish its drying.

The glue made of finews, feet, &c. is managed after the same manner; only with this difference, that they bone and scour the feet, and do not lay them to steep.

Of this commodity there is a very great exportation from England; the English glue being universally allowed to be the best in Europe, partly from the excellency of the materials, and partly from the skill of the manufacturers. Next to this is the Flanders glue. In both countries it is made by the tanners from fragments of good skins dried with much care. In France it is a separate trade: and the glue-makers pick up their materials as they can, from the several dealers in skins, and boiling these with cow-heels make their glue; which as they purchase every thing, must render it dear, as well as of an inferior quality. The duty on exportation is tenpence, and on importation three shillings and tenpence, on every hundred weight.

The best glue is that which is made from the skin of the oldest beast, especially if a bull's hide is used. Experience likewise shows that glue is considerably improved in quality by keeping after it is made; and the surest way to try its goodness is to lay a piece to sleep three or four days, and if it swell considerably without melting, and when taken off resumes its former dryness, it is excellent.

A glue that will hold against fire or water, it is said, GLU

Glue may be made thus: Mix a handful of quicklime with four ounces of linseed oil; boil them to a good thickness; then spread it on tin-plates in the shade, and it will become exceeding hard, but may be easily dissolved over a fire, as glue, and will effect the buffets to admiration.

Neumann observes, that glue dissolved in a solution of lapis calaminaris in spirit of nitre, and afterwards inspissated, forms an extremely slippery tenacious mass, which might be of use for entangling flies, caterpillars, and other insects, if it was not too expensive.

Method of Preparing and Using Glue. Set a quart of water on the fire, then put in about half a pound of good glue, and boil them gently together till the glue be entirely dissolved and of a due consistence. When glue is to be used, it must be made thoroughly hot; after which, with a brush dipped in it, besmear the faces of the joints as quick as possible; then clapping them together, slide or rub them lengthwise one upon another, two or three times, to settle them close; and so let them stand till they are dry and firm.—Mr Boyle gives a receipt for preparing a fine strong glue from flingflats in the following manner: Steep the flingflats for 24 hours in common brandy. When the menstrum has opened and mollified the flingflats, they must be gently boiled together, and kept stirring till they appear well mixed, and till a drop thereof, suffered to cool, turns into a strong jelly. Then strain it, whilst hot, through a clean linen cloth into a vessel to be kept close stopped. A gentle heat suffices to dissolve this glue into a transparent and almost colourless fluid, but very strong; so that pieces of wood glued together with it will separate elsewhere rather than in the place where they are joined. See ISINGLASS.