COMMENTARY. On the formation of _Resins_ see in particular Theophrastus (H. P. ix, 2) and Pliny (H. N. xxiv, 22.) Pliny thus sums up his account of them: “Summæ species duæ; sicca et liquida. Sicca e pinu et picca; liquida e terebintho, larice, lentisco, cupresso.” The Resina sicca pini is the _Pix arida_ of the Old London Pharmacopœia, or the _Pix Abietina_ of the New. The Resina liquida laricis is now generally called by the name of _Venice Turpentine_. The Resina lentisci is well known by the name of _Mastich_. The _Colophonian rosin_, which is often mentioned in this work, is the same as the black fiddler’s rosin. The Cypress rosin does not appear to be much known now. Pliny correctly observes that all these resins act on the bowels and the urine. The mode of burning or roasting resin is described by Dioscorides. (i, 93.) He gives a very interesting account of the _resinæ_ in general, which he represents to be emollient, calefacient, dissolvent, cleansing, suited for coughs and consumptions, in electuaries by themselves or with honey, clearing away matters from the chest; and as being diuretic, digestive, laxative of the bowels; adapted for the operation on trichiasis (see Book VI, 8), and for leprosy, with verdigris, copperas, and natron; for purulent ears with honey and oil, and for itching of the pudendum. They are mixed, he adds, with plasters, liniments, and acopa, and relieve pleuritic pains either when rubbed in or applied by themselves. (i, 91.) All the other authorities prescribe the resins freely, but none give so full a description of them as Dioscorides. See, however, Celsus (pluries), who appears to have been particularly fond of them. He recommends turpentine rosin with butter and honey in phthisis (iii, 22), in dyspnœa (iv, 4, 2), and in various other cases. Our author’s account of them would seem to be principally taken from Galen. The Arabians, as usual, copy from the Greeks, and supply little additional of their own. See Avicenna (ii, 2, 242); Serapion (De Simpl. 325); Averrhoes (Collig. v, 42); Rhases (Cont. l. ult. i, 580, &c.); Ebn Baithar (pluries.) All the resinæ here described occur in the modern Greek Pharmacopœia (160, 161.) Ῥόδα, Rosæ, _Roses_, are naturally composed of a watery substance, which is heating, astringent, and bitter. The flowers are still more astringent, and hence are desiccative. * * * * *