U M ntber soft and trtn parent, pale yellowish colour, inclinii n , and of :i strong but pi I. Ii w .is formerly empl nto.c than it i ; - it, in the <• impound ointment ofElemi, v. hich baa long been used for digesting and cleansing ul us uti itv in medicine, is of considerable service in the Arts ; anil. lent quan- tities of it cannot nh:- oared genuine, different persons have endeavoured to contrive such substitutes, as would effectually answer r! es. — From these, v. t Iku the follow- ing, as being most easily prepared, -and chiefly from substance s pro- duced in this country : The first is the invention ot" Mr. Alf.ekt Angell, ofBethnal- green, Middlesex, to whom a pa- tent was granted in January 17SI, for his Britannic Elastic Gum. This pre juration consists of one gallon of linseed, or nut-oil, lib. of bees- wax, {jibs, of glue or size, lb. of verdigrease, a similar quantity of li- tharge, and two quarts of spring or rain-water. These ingredients are to be melted in an iron kettle,, till they acquire the consistence of gum. — The patentee observes, that such composition is particularly serviceable in the various branches of portrait and house-painting, as it renders the colours durable, and free from peeling : it is also said to be of great uti ity in the gilding, painting, &c. of silks, calicoes, &c. and in dressing silk, linen, or cot- ton, in the loom, instead of gum or paste, so as to strengthen the threads of the finest cottons. He states a variety of other uses, a mi- nute account of which the curious reader will find in the 3d vol. of G U M [415 fuifii. In es." Aj tained in Cl UA1- ■ n .' . ' . I inven I to hku) cti a substitute fur gum, in thick irs for pri . and at a 1 liable rate. — This article is by boiling fli r, i:l the whole substance ii
- extracted ; the liquor is
next to be 1 linen or woollen cloth, and boiled down to tl nice of a jelly. It is then to be put into a dose vessel, an . a small quantity of spirits, or I oil, poured on the top, in order to preserve it in a fresh state. — In using this substitute, the printer is directed to put a certain portion Into a gallon of colour, ac- cording to the nature of the latter, and the particular kind of work; while he should regulate "himself, by trial, in the same manner as is practised in employing common gum. GUM, or Gum-Sf.ckction, i:i horticulture, is a kind ofgangn or morbid production of gummy matter, exuding from the wounded alburnum or sap-wood of d duous trees, whether the injury be caused by internal disease, or by external violence, as is the case in can er. Cherry and other stone-fruit trees are particularly affected with this exudation of gum, which, however, concretes in dry weather, and thus its farther discharge is prevented : otherwise the tree would weep, and perish from a deficiency of nourishment. Dr. Darwin conjectures this gummy substance to be part of the nutritious
