Mouth Glue affords a very convenient means of uniting papers, and other small light objects; it is made by dissolving, by the aid of heat, pure glue, as parchment glue, or gelatine, with about one-quarter or one-third of its weight of coarse brown sugar in as small a quantity of boiling water as possible; this, when perfectly liquid, should be cast into thin cakes on a flat surface very slightly oiled, and as it cools, cut up into pieces of a convenient size. When required for use one end may be moistened by the mouth, and is then ready to be rubbed on any substances it may be wished to join; a piece kept in the desk or work-box is exceedingly convenient.
Paste is usually made by rubbing up flour with cold water, and boiling; if a little alum is mixed before boiling it is much improved, being less clammy, working more freely in the brush and thinner ; a less quantity is required, and it is therefore stronger. If required in large quantity, as for papering rooms, it may be made by mixing one quartern of flour, one-quarter pound of alum, and a little warm water; when mixed, the requisite quantity of boiling water should be poured on whilst the mixture is being stirred. Paste is only adapted to cementing paper; when used it should be spread on one side of the paper, which should then be folded with the pasted side inwards, and allowed to remain a few minutes before being opened and used ; this swells the paper, and permit its being more smoothly and securely attached. Kept for a few days, paste becomes mouldy, aud after a short time putrid. This inconvenience may be obviated by using the
Permanent Paste, made by adding to each half-pint of flour-paste, without alum, fifteen grains of corrosive sublimate, previously rubbed to powder in a mortar, the whole to be well mixed this, if prevented from drying, by being kept in a covered pot, remains good any length of time, and is therefore convenient; but unfortunately it is extremely poisonous, though its excessively nauseous taste would prevent its being swallowed accidentally; it possesses the great advantage, of not being liable to the attacks of insects.