in Natural History, a viscid juice oozing either spontaneously, or by incision, from several trees, as the pine, fir, &c.—A premium for several years has been offered by the London Society for Encouraging Arts, &c. for discovering a mode of reducing the inflammable quality of resin, so as to adapt it to the purposes of making candles; but no such discovery has yet been made.

Elastic RESIN. See CAOUTCHOUC, CHEMISTRY Index.

Gum RESIN, a mixture of gum and resin. See CHEMISTRY and MATERIA MEDICA Index.

Red Gum RESIN, is procured from the red gum tree, or eucalyptus resinifera; a tree so large and lofty as to exceed in size the English oak. The wood of the tree is brittle, and of little use but for firewood, from the large quantity of resinous gum it contains. The tree is distinguished by having pedunculated flowers, and an acute or pointed conical calyx. To obtain the juice from this tree incisions are made in the trunk of it, and sometimes upwards of 60 gallons of red resinous juice have been obtained from one of them. "When this juice is dried, it becomes a very powerful astringent gum-resin, of a red colour, much resembling that known in the shops by the name of kino, and, for all medical purposes, fully as efficacious. Mr White administered it to a great number of patients in the dysentery, which prevailed much soon after the landing of the convicts, and in no one instance found it to fail. This gum-resin dissolves almost entirely in spirit of wine, to which it gives a blood-red tincture. Water dissolves about one-fifth part only, and the watery solution is of a bright red. Both these solutions are powerfully astringent."

Yellow Gum RESIN, is procured from the yellow resin tree, which is as large as the English walnut tree. The properties of this resin are equal to those of the most fragrant balsams. It exudes from the bark spontaneously, but more readily if incisions are made. The colour of it is yellow, and at first it is fluid; but after being infused in the sun, it becomes solid. When burnt on hot coals, it smells like a mixture of balsam of Tolu and benzoin, approaching somewhat to florax. "It is perfectly soluble in spirit of wine, but not in water, nor even in essential oil of turpentine, unless it be digested in a strong heat. The varnish which it makes with either is very weak, and of little use. With respect to its medicinal qualities, Mr White has found it, in many cases, a good pectoral medicine, and very balsamic. It is not obtainable in so great abundance as the red gum produced by the eucalyptus resinifera. The plant which produces the yellow gum seems to be perfectly unknown to botanists, but Mr White has communicated no specimens by which its genus or even class could be determined."