Medicinal Substances obtained from the preceding Coniferous Plants.

The term turpentine (terebinthina) is ordinarily applied to a liquid or soft solid oleo-resinous juice of certain coniferous plants, as well as of the Pistachia Terebinthus, a plant of the order Terebintaceae., Juss. Indeed, this last-mentioned plant, Pistachio Terebinthus, is probably the true Terebinthus of the ancients (Τερμίνθος, Theoph. and Dioscorides). When submitted to distillation, these juices are resolved into volatile oil and resin. The roots, and other hard parts of coniferous trees, yield, by a kind of distillatio per descensum, the thick liquid called tar, from which pitch is procured. Hence it will be convenient to speak of the coniferous terebinthinates under four heads: 1st, the oleo-resinous juices; 2dly, the volatile oil obtained therefrom by distillation; 3dly, the resinous residuum; 4thly, tar and pitch.

1. Oleo-Resinae Terebinthinae.—Terebinthinate Oleo-Resins.

At first these oleo-resins are liquid, but by age and exposure to the air they become, more or less speedily in the different varieties, solid, partly by the volatilization, and partly by the resinification of the volatile oil. They have a certain general similarity in taste and odour. They soften and become very fluid by heat, readily take fire in the air, and burn with a white flame, and, if the supply of air be limited, with the copious deposition of finely-divided carbon (lamp black). They are almost completely soluble in alcohol and ether; and yield, by distillation, a volatile oil and a resinous residuum. It must not be inferred that the identical volatile oil and resin into which these oleo-resins are resolved by distillation pre-exist in the juices which yield them; for in some cases it is certain they do not, but are products, not educts, as I have elsewhere [Pharmaceutical Journal, vol. v. p. 67, 1845.] shown. Thus balsam of Canada possesses the property of right-handed circular polarization; and, by distillation, yields a volatile oil and a residual resin, both of which enjoy the power of left-handed circular polarization. It is obvious, therefore, that during distillation some molecular change must have been effected in the proximate principles of the balsam. American turpentine, on the other hand, possesses the power of left-handed circular polarization; but, by distillation, yields a volatile oil (oil of turpentine of English commerce) which produces right-handed polarization.

Water acquires a terebinthinate flavour when digested with them; and by the aid of the yolk or the white of an egg, or, still better, by that of vegetable mucilage, forms an emulsion with them.

1. Common Turpentine (Terebinthina vulgaris).—Under this name we find oleo-resins brought from various parts of the world, obtained from different species of Pinus, and, though agreeing in the main in their properties, possessing certain distinctive characters. At the present time, the London market is almost exclusively supplied from the United States of America, a small quantity only being occasionally imported from Bordeaux.

α. American or White Turpentine, Terebinthina Americana, L. (the Térébenthine de Boston of the French) "is procured chiefly from the Pinus palustris, partly, also, from the Pinus Taeda, and perhaps some other species inhabiting the Southern States. In former times, large quantities were collected in New England; but the turpentine trees of that section of the Union are said to be nearly exhausted; and our commerce is almost exclusively supplied from North Carolina and the southeastern parts of Virginia." [United States Dispensatory.]

The method of procuring this turpentine is as follows: A hollow is cut in the tree, a few inches from the ground, and the bark removed for the space of about 18 inches above it. The turpentine runs into these excavations from about March to October; more rapidly, of course, during the warmer months. It is transferred from these hollows into casks [Michaux, N. Am. Sylv. iii.; Way, Trans. of the Society of Arts, vol. xxviii. p. 89; Duhamel, Traité des Arbres, t. ii. p 146, Paris, 1755.]

It is imported from New York in casks; those from North Carolina holding 2 cwts., while those from South Carolina contain 2 ½ cwts. It is yellowish-white, with an aromatic odour, and a warm, pungent, bitterish taste. It is translucent or opake. Its consistence varies, being semifluid, or, in cold weather, that of a soft solid. It contains various impurities (leaves, twigs, chips, &c). That got from the first tappings is the best, and is called virgin turpentine. Recent American turpentine is said [United States Dispensatory.] to yield 17 per cent. of essential oil.

This sort of turpentine possesses the property of left-handed circular polarization; but it yields by distillation a volatile oil having right-handed polarization.

American turpentine is melted and strained, and in this state it is sometimes called refined turpentine.

Old and concrete American turpentine is sometimes sold for frankincense (thus vel abietis resina).

β. Bordeaux Turpentine is obtained by making incisions in the Pinus Pinaster, Lambert (P. maritima, DC.), and collecting the turpentine in hollows at the foot of the tree. Every month these hollows are emptied, and the oleo-resin conveyed in pails to a reservoir. In this state it is called soft gum (gomme molle). It is purified either by heating it in large boilers, and filtering through straw (térébenthine galipot), or by exposing it in a barrel, the bottom of which is perforated by holes, to the sun; the liquid which drains through is called térébenthine au soleil. The last method yields the best product, since less volatile oil is dissipated by it. [Guibourt, Hist. des Drog. t. ii. p. 578; Duhamel, Traité des Arbres, t. ii. p. 147.] The turpentine which flows during the winter is called galipot in Provence, barras in Guienne. It is in the form of semi-opake, solid, dry crusts of a yellowish-white colour, a terebinthinate odour, and a bitter taste. [Guibourt, op. cit.]

Bordeaux turpentine is whitish, thickish, and turbid. It has a disagreeable odour, and an acrid, bitter, nauseous taste. On standing, it separates into two parts: one thinner, yellow, and almost transparent; another thicker, whitish, and of the consistence of thick honey, having a granular consistence. Bordeaux turpentine readily becomes hard and dry by exposure to the air. It possesses the property of left-handed circular polarization; and yields by distillation an oil which also has left-handed polarization. It enjoys, with balsam of copaiva, the property of solidifying with magnesia, and in this respect is distinguished from Strasburgh turpentine.

Common turpentine has been analyzed by MM. Moringlane, Duponchel, and Bonastre, [Journ. de Pharm, t. viii. p. 329] and by Unverdorben. [Berzelius, Traité de Chim.; and Gmelin, Handb. de Chem.] The last-mentioned chemist found it to consist of two volatile oils (oil of turpentine), pinic acid, a little sylvic acid, a trace of an indifferent resin not soluble in oil of petroleum, and a small quantity of bitter extractive. The quantity of volatile oil varies from 5 to 25 per cent. of the weight of the turpentine. Laurent has discovered in Bordeaux turpentine a resinous acid, pimaric acid, isomeric with pinic acid.

2. Larch or Venice Turpentine (Terebinthina veneta; Terebinthina laricea). Obtained from Larix Europaea, DC., by boring the trunks of the trees, and adapting to each hole a wooden gutter, which conveys the juice into a tub or trough, from which it is afterwards withdrawn for filtration. [Duhamel, Traité des Arbres, t. i. p. 335.]

Through the kindness of Professor Guibourt I have received an authentic sample of larch turpentine. It was collected in the wood of the Bishop of Maurienne, in Savoy, by order of the bishop, and at the urgent solicitation of M. Bonjean, pharmacien, naturalist of Chambery. The same kind of turpentine, collected in Switzerland (Swiss turpentine) [Guib. MSS.] is sold in Paris as Strasburg turpentine (Térébenthe de Strasbourg), [Idem. Hist. des Drog. 3me éd. t. ii. p 577.] and was formerly called Venice turpentine. It is a thick and consistent fluid, flowing with difficulty, is sometimes transparent, but more frequently cloudy, has a yellow or greenish-yellow tint, an odour which is peculiar, not very agreeable, weaker than that of either Strasburg or common turpentine, but less disagreeable than the latter, and an acrid, very bitter taste. It has little or no tendency to concrete by keeping—a property known to Pliny, [Hist. Nat. lib. xvi. cap. 19. ed. Valp.] and which distinguishes it from common turpentine.

A factitious substance (terebinthina veneta factitia) is sold by London druggists for Venice turpentine. It is prepared by melting together oil of turpentine and black rosin. A similar preparation is found in the shops of the United States of America, [United States Dispensatory.] and is probably identical with that imported from America under the name of Venice turpentine. [Dr. Maton, in Labert's Description of the Genus Pinus; and Dr. A. T. Thomson, London Dispensatory.]

Berzelius and Unverdorben [Berzelius, Traité de Chim. t. v. p. 477; and Gmelin, Hand. d. Chim.] have submitted Venice turpentine to examination, and with the following results:—

Larch resin yields, according to Berzelius, [Berzelius, op. cit.] from 18 to 25 per cent. (according to Guibourt only 15 to 24 per cent.) of volatile oil which possesses the power of left-handed circular polarization. Its odour is citron-like, and on this account the oil might be substituted for essence of lemons in the preparation of scouring drops. Its sp. gr. is 0.863.

3. Strasburg Turpentine (Terebinthina argentoratensis; Térébenthine au citron, ou Térébenthine d'Alsace, Guib.)—This is obtained from Abies Picea. The peasantry, in the vicinity of the Alps, collect it by puncturing the vesicles adhering to the bark with sharp-pointed hooks, and receiving the juice in a bottle. It is afterwards filtered through a rude kind of bark funnel. [Duhamel, Traité des Arbres, t. i. p. 9.]

Strasburg turpentine is very fluid, transparent, of a yellowish colour, has a very agreeable odour of citron, and a taste moderately acrid and bitter. It consists, according to Caillot, [Journ. de Pharm. xvi. p. 436.] of volatile oil 33.5, resin insoluble in alcohol 6.20, abietin (a crystallizable resin) 10.85, abietic acid (? pinic and sylvic acids) 46.39, extractive and succinic acid 0.85, loss (principally volatile oil) 2.21.

4. Canadian Turpentine, or Canada Balsam (Terebinthina canadensis; Balsamum canadense), is obtained from Abies balsamea in Canada and the State of Maine. Between the bark and the wood of the trunks and branches of these trees are vesicles containing this oleo-resin, which exudes when they are broken, and is received in a bottle. It is imported in casks containing each about one cwt. When fresh it has the consistence of thin honey, but by age gradually solidifies: it is yellow, transparent, very tenacious, of a peculiar and agreeable terebinthinate odour, and of a slightly bitter, somewhat acrid, taste. Like Bordeaux turpentine, it solidifies when mixed with a sixth of its weight of calcined magnesia. It is imperfectly soluble in alcohol.

Canada balsam has been analyzed by Bonastre, [Journ. de Pharm viii. 337.] who obtained the following results: volatile oil 18.6, resin easily soluble in alcohol 40.0, subresin difficultly soluble 33.4, fibrous caoutchouc, like subresin, 4.0, acetic acid traces, bitter extractive and salts 4.0.

Balsam of Canada possesses the property of right-handed circular polarization; but both the oil and resin, into which it is resolved by distillation, have left-handed polarization. [See a paper by the author, in the Pharmaceutical Journal, vol. v. p. 67, 1845.]

Canada balsam is used by varnish-makers, by opticians as a cement, and by microscopists as a medium for mounting objects in.

The great value of Canada balsam for optical purposes depends on its transparency and its refractive power, which is nearly equal to that of glass. When used to connect the pieces of an achromatic lens, it prevents the loss of light by reflexion, and excludes moisture and other foreign bodies from the space between the surfaces of the glasses. In Nicol's prisms (single image prisms of Iceland spar), it serves the important purpose of transmitting the ordinary ray, and of interrupting the passage of the extraordinary one; its index of refraction being intermediate between that of Iceland spar for the ordinary ray and that of the same substance for the extraordinary ray. The following table of indices of refraction serves to illustrate the preceding statements:—

5. Common Frankincense (Abietis resina; Thus).—This is the spontaneous exudation of Abies excelsa. I am indebted for an authentic sample of this oleo-resin to Mr. Daniel Banbury, who collected it, in the autumn of 1849, from the A. excelsa, in Switzerland. It is a soft solid, glistening in places, as if covered with a film of water. Its colour is not uniform: it is whitish, yellowish, pinkish, or pale violet red, and dark in different portions. The pinkish or violet red or peach-blossom hue seems to have been produced by exposure of the resin to the air and light, and in this circumstance resembles the peach-blossom red colour which assafetida acquires under similar circumstances. It is probable, however, that this tint is not permanent. Its odour is not disagreeable, but is somewhat like that of Strasburg turpentine. Guibourt says it is analogous to that of castoreum. The taste is balsamic, and without any bitterness.

When melted in water, and strained through a coarse cloth, it forms Burgundy pitch (pix abietina vel burgundica; poix jaune ou blanche). An authentic sample, prepared by Mr. D. Hanbury from thus collected by himself, is of an opake whitish-yellow colour, somewhat resembling emplastrum plumbi.

The substance sold as common frankincense in the London shops is usually concrete American turpentine; and most of the so-called Burgundy pitch found in commerce is a fictitious article.

Common frankincense or thus has been analyzed by Caillot, [Journ. de Pharm. t. xvi. p. 436.] who obtained the following results: volatile oil 32.00, resin insoluble in alcohol 7.40, abietin (a crystallizable resin) 11.47, abietic acid (? pinic and sylvic acids) 45.37, extractive and succinic acid 1.22, loss (principally volatile oil) 2.54.

Physiological Effects.—The effects of terebinthinate substances have been before noticed (see vol. i. p. 254). Locally they operate as irritants. Applied to the skin they cause rubefaction, and sometimes a vesicular eruption. Swallowed they give rise to a sensation of warmth at the stomach, in large doses occasion sickness, and promote the peristaltic movement of the intestines. After their absorption they operate on the general system as stimulants, and excite the vascular system, especially of the abdominal and pelvic viscera. Their influence is principally directed to the secreting organs, more especially to the mucous membranes and the urinary apparatus. They act as diuretics, and communicate a violet odour to the urine. This odour depends on a portion of the oil having undergone a slight change in its nature during its passage through the system. Part of the oil, however, is thrown off unchanged; for Moiroud [Pharmacol.-Vétérin. p. 312.] has observed that, at the same time that the turpentines cause a violet odour, they flow in part with the urine. "I have verified," says he, "this double phenomenon on many horses, to whom turpentine has been given, for some days, in the enormous dose of ten or twelve ounces." But the kidneys are not the only parts engaged in getting rid of the absorbed turpentine. All the secreting organs, but more especially the bronchial surfaces and the skin, are occupied in the same way. By these the oil is exhaled apparently unchanged, or at least with its usual odour. During the circulation of the terebinthinate particles in the system, they exercise a local influence over the capillaries and secerning vessels, in the vital activity of which they effect a change. In certain morbid conditions, this change is of a most salutary nature. In catarrhal affections of the mucous membranes the secerning vessels become constringed under the use of terebinthinates, and the discharge is, in consequence, checked.

The most important, because by far the most active, constituent of the terebinthinate oleo-resins is volatile oil. Hence their effects are almost identical with those of the latter, and will be noticed hereafter (see p. 1193). Some slight differences, however, are to be noticed. They are less rapidly absorbed, are more permanent in their operation, confine their influence principally to the apparatus of organic life, not affecting, at least to the same extent, the brain, and act less powerfully on the cutaneous system.

We have few data on which to rely in judging of the comparative influence of the different terebinthinates; but as their most active constituent is volatile oil, we may fairly infer that those which possess the greatest liquidity, and which, in consequence, contain the largest quantity of oil, are the most powerful preparations. Venice and Strasburg turpentines stand in this respect pre-eminent. Canada balsam is valuable on account of its purity and agreeable flavour. In activity, purity, and flavour, common turpentine holds the lowest rank.

Uses.—The terebinthinate oleo-resins are, with some exceptions, applicable for the same purposes as the volatile oil. The following are the principal cases in which they are employed:—

1. In mucous discharges from the urino-genital organs; as gonorrhoea, gleet, leucorrhoea, and chronic cystirrhoea.

2. In chronic catarrh, both mucous and pituitous, occurring in old persons of a lax fibre and lymphatic temperament.

3. In chronic mucous diarrhoea, especially when accompanied with ulceration of the mucous follicles.

4. In colic and other cases of obstinate constipation, Cullen [Treat. of the Mat. Med.] found a turpentine emulsion used as a clyster "one of the most certain laxatives."

5. In chronic rheumatism, especially sciatica and lumbago, the turpentines are occasionally used.

6. As detergents and digestives they have been sometimes applied to indolent and ill-conditioned ulcers.

Administration.—The dose of the terebinthinate oleo-resins is from a scruple to a drachm. They are given in the form of pill, emulsion, or electuary. To communicate to the softer kinds a consistence fit for making pills, liquorice powder may be added to them. Bordeaux turpentine and balsam of Canada, mixed with about one twenty-eighth part of their own weight of calcined magnesia, solidify in about twelve hours; the acid resins combine with the magnesia, and form solid resinates, which absorb the volatile oil. A turpentine emulsion is made with the yolk of egg, or mucilage of gum Arabic, sugar, and some aromatic water. To form an electuary the turpentine is mixed with sugar or honey. An emulsion, containing from half an ounce to an ounce of turpentine, may be used as a clyster, in obstinato constipation, asearides, &c.

The terebinthinate oleo-resins yield several officinal substances, and enter into several preparations:—

1. Terebinthina vulgaris yields Oleum Terebinthinae and Resina; and enters into the composition of Emplastrum Galbani, L., and Unguentum Elemi, L.

2. Terebinthina veneta is a constituent of Emplastrum Cantharidis compositum, E., and Unguentum Infusi Cantharidis, E.

3. Abietis Resina; Thus, yields Pix Burgundica, L. E. D.; and enters into the composition of Emplastrum Galbani, L., Emplastrum Opii, L., Emplastrum Picis, L., Emplastrum Calefaciens, D., Emplastrum Ferri, L. D., and Emplastrum Cumini, L.

The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1854.