TO MAKE PORTABLE GLUE. Take one pound of the best glue, boil and strain it very clear; boil likewise four ounces of isinglass, put it in a double glue-pot, with half a pound of fine brown sugar, and boil it pretty thick; then pour it into moulds; when cold, cut and dry them in small pieces. This glue is very useful to draughtsmen, architects, &c., as it immediately dilutes in warm water, and fastens the paper without the process of damping. TO MAKE GLUE THAT WILL RESIST MOISTURE. Dissolve gum sandarach and mastic, of each two ounces, in a pint of spirit of wine, adding about an ounce of clear turpentine. Then take equal parts of isinglass and parchment glue, made according to the directions in the preceding article, and having beaten the isinglass into small bits, and reduced the glue to the same state, pour the solution of the gums upon them, and melt the whole in a vessel well covered, avoiding so great a heat as that of boiling water. When melted, strain the glue through a coarse linen cloth, and then put it again over the fire, adding about an ounce of powdered glass. This preparation may be best managed by hanging the vessel in boiling water, which will prevent the matter burning to the vessel, or the spirit of wine from taking fire, and indeed it is better to use the same method for all the evaporations of nicer glues and sizes; but, in that case, less water than the proportion directed, should be added to the materials. ANOTHER METHOD. A very strong glue, that will resist water, may be also made by adding half a pound of common glue, or isinglass glue, to two quarts of skimmed milk, and then evaporating the mixture to the due consistence of the glue. TO MAKE PARCHMENT GLUE. Take one pound of parchment, and boil it in six quarts of water, till the quantity be reduced to one quart; strain off the fluid from the dregs, and then boil it again till it be of the consistence of glue. The same may be done with glovers’ cuttings of leather, which make a colorless glue, if not burnt in the evaporation of water. A VERY STRONG COMPOUND GLUE. Take common glue in very small or thin bits, and isinglass glue: infuse them in as much spirit of wine as will cover them, for at least twenty-four hours. Then melt the whole together, and, while they are over the fire, add as much powdered chalk as will render them an opaque white. The infusion in the spirit of wine has been directed in the recipes given for glue; but the remark on the use of it in one of the preceding articles will hold good also in this, and the mixture may be made with water only. TO MAKE COMPOUND GLUE.