This greatly diminished importation of the crude article is partially explained by a larger importation of Oil of Turpentine and Rosin; but the increase is by no means sufficient to account for the vast diminution indicated by the above figures. The quantities of these latter articles imported into the United Kingdom during the year 1872 were as follows:—Oil of Turpentine, 220,292 cwt., value £470,085, six-sevenths being furnished by the United States of America and the remainder chiefly by France. Rosin, 919,494 cwt., value £492,246; of this quantity, the United States supplied nine-tenths, and France the larger part of the remainder.[2280]
Uses—Turpentine, Common Frankincense and Colophony are ingredients of certain plasters and ointments. Oil of turpentine is occasionally administered internally as a vermifuge or diuretic, and applied externally as a stimulant. But these substances are immeasurably less important in medicine than in the arts.
Thus Americanum vel vulgare.
This substance, known among druggists as Common Frankincense or Gum Thus, is the resin which, as explained at [p. 605], concretes upon the stems of the pines in the American turpentine orchards, and is there called Scrape. It corresponds to the Galipot or Barras of the French, which in old times supplied its place.
It is a semi-opaque, softish resin, of a pale yellow colour, smelling of turpentine; it is generally mixed with pine leaves, bits of wood and other impurities, so that it requires straining before it is used. By keeping, it becomes dry and brittle, of deeper colour and milder odour. Under the microscope, it exhibits a crystalline structure due to Abietic Acid, of which it chiefly consists. It is imported from America in barrels, but in insignificant quantities and only for the druggist’s use. Sometimes, however, it is distilled as common turpentine.
Dry pine resin, of which Common Frankincense is the type, evolves when heated an agreeable smell; hence in ancient times it was commonly used in English churches in place of the more costly olibanum. At present it is scarcely employed except in a few plasters.
TEREBINTHINA VENETA.
Terebinthina Laricina; Venice Turpentine, Larch Turpentine; F. Térébenthine de Venise ou de Briançon, Térébenthine du mélèze; G. Venetianischer Terpenthin, Lärchen-Terpenthin.
Botanical Origin—Pinus Larix L. (Larix europæa DC.), a tall forest tree of the mountains of Southern Central Europe, from Dauphiny through the Alps to Styria and the Carpathians, ascending to an elevation of 3000 to 5500 feet above the sea-level. It is largely grown in plantations in England and also, since 1738, in Scotland.
History—The turpentine of the larch was known to Dioscorides as imported from the Alpine regions of Gaul.[2281] Pliny also was acquainted with it, for he correctly remarks that it does not harden. Galen in the 2nd century also mentions it, admitting that it may well be substituted for Chian turpentine ([see p. 165]), the true, legitimate Terebinthina. Yet even in the beginning of the 17th century many pharmacologists complained of such a substitution. Mattioli[2282] gave an account of the method of collecting it about Trent in the Tirol, by boring the trees to the centre, which is true to the present day. It used formerly to be exported from Venice, then the great emporium for drugs of all kinds; the turpentine may even at times have been collected in the territories of the Venetian republic. We find it expressly called Terebinthina Veneta by Guintherus of Andernach.[2283]