Medical properties and uses. -The Turpentines and their essential oil are stimulant, cathartic, diuretic, anthelmintic, and externally rubefacient. Of those which I have described the Venice and Canada turpentines are more generally employed for internal purposes; the common turpentine proving offensive to most stomachs, and the Chian not being easily procured. The ancients were well acquainted with the medi-einal properties of turpentines2; and, besides the diseases for which they are prescribed by the moderns, gave them liberally in coughs and all pulmonary affections. Turpentines seem to derive their virtues from the volatile oil which they contain. When swallowed, they produce a sensation of warmth in the stomach, at first increasing the quickness and force of the pulse, but afterwards diminishing it; and if the dose be large, some degree of nausea is excited, with slight vertigo, and soon, but not always, a copious discharge from the bowels; but if the dose be small, they act chiefly upon the kidneys.

The cathartic operation of large doses of the oil, in particular, seems to counteract the determination to the kidneys, which smaller doses produce; for in doses of even f 3 x. and f 3 xij., no other effect on the urinary organs is perceived than the violet smell of the urine.1 The odour of violets is produced by the oil, even when it is neither taken into the stomach, nor rubbed upon the skin; for if a quantity of oil of turpentine be poured on a table in a room, this odour will be perceived in the urine of any one who remains in the room for half an hour, or even a shorter time. When breathed, it is perceptible in the urine in fifteen minutes; and when rubbed on the skin, in twenty-five minutes.2 Turpentines are chiefly prescribed in gleet, leucorrhoea, mucous obstructions of the urinary passages, and calculous affections; but in the latter cases their stimulant operation on the kidneys requires that they be given with caution. The oil is justly regarded as a useful remedy in lumbago, sciatica, and some other varieties of chronic rheumatism and neuralgia, particularly when combined with the cinchona bark. Dr. Copland, in a valuable paper on terebinthinous remedies3, recommends the oil strongly in the haemorrhagiae, particularly in atonic epistaxis and haemoptysis.

He also confirms Dr. Percival's statement of its efficacy in epilepsy; and extols its powers in infantile convulsions, arising from a disordered state of the alimentary canal, and from erysipelas. It exerts a powerful influence on the uterine organs; and thence is useful in chlorosis. Dr. Copland states some cases of ovarian dropsy, in which the effects of the oil were such as to recommend its employment in incipient cases of this disease; and also in other dropsies, not even excepting hydrocephalus: but our experience has not confirmed these opinions. Dr. Cheyne says, in melaena, a disease which depends upon an excited state of the capillaries I have given oil of turpentine with complete success. From its action in the abdominal viscera, it has proved useful in symptomatic epilepsy.

1 Hatchett, Phil. Trans. 1806. 2 See Dioscor. lib. i. cap. 91. p. 50. Aretaeus passe lib. iv. etc.

Transactions of the London Medical Society, i. part i. 212, 227.

2 Journal Complementaire, Oct. 1826.

3 Med. and Phys, Journ. vol. xlvi. pp. 185. 206.

For the expulsion of the tape-worm the power of the oil of turpentine is now generally known. It differs in its action from the other remedies which have been employed against tape-worm, by killing the worm before its expulsion; and thence it is more permanently useful.1 Neither wine nor spirits should be drunk during the use of the oil; the usual quantity of food should be diminished; and the use of the oil should be immediately discontinued, if an eruption resembling eczema appear on the skin, which is apt to arise from its employment in some habits. As local stimulants, turpentines and the oil of turpentine have been efficaciously exhibited in the form of enema, in cases of colic, obstinate costiveness, and ascarides. The oil is useful when dropped into the ear in deafness from defect of wax; and is an excellent addition to embrocations in acute rheumatism, bruises and paralysis of the extremities. As a discutient, it is applied to indolent tumours, and is a useful primary application to burns.

Turpentines are given in doses of grs. x. to 3 j., either made into pills with powdered liquorice root, or diffused in water by means of almonds, mucilage, or yoke of egg and sugar. The dose of the oil may be x. to 3j, to produce its diuretic effect: but in doses of f3j. to f 3 ij., its effects are more general on the system. In these doses, it may be combined with aromatics and spices, and rubbed up with mucilage or honey. Dr. Copland recommends the addition of the tincture of capsicum, for correcting the nauseating and unpleasant effects which the oil frequently produces on the stomach. For the expulsion of taenia, it is necessary to give from f ss. to f ij. of the oil, repeated every eight hours till the worm be ejected: and in these large doses it is more easily taken when exhibited uncombined, or when merely floated upon water with the addition of a drop or two of any aromatic oil. If it do not operate by stool in four or five hours after it has been taken, a dose of castor oil should be exhibited.

Tar is stimulant, diuretic, and sudorific; and externally detergent. In the solid state, made into pills, it has been beneficially used in ichthyosis; but it is more generally employed in the form of tar water, aqua picis liquidae. As an external application, it has been found beneficial in Porrigo scutulata, foul ulcers, and some other cutaneous diseases.

The resins and Burgundy pitch are adapted for external use only; the former entering into the composition of some ointments and plasters; the latter being used as a rubefacient plaster. The pitch excites some degree of inflammation, sometimes a pimply eruption, and a purulent exudation, from the part over which it is applied, without raising the cuticle. It is used in cases of catarrh, pertussis, dyspnoea, and chronic rheumatism; and seems to be chiefly serviceable from the length of time it adheres to the skin, and by which its action can be continued.

1 In all the cases of the expulsion of taenia by oil of turpentine, the ejected worm has generally had a livid hue, without any appearance of animation.

Officinal preparations.-Of Turpentine : Oleum Terebinihinae purificatum, L. D. Oleum Terebinihinae rectificatum, D.-Of the Oil: Linimentum Terebinihinae, L. D.-Of Yellow Resin : Emplast. Resince, L. E. D. Ceraium Resinae, L. E.-Of Burgundy Pitch: Emplast. Picis, L. E.-Of Tar : Aqua Picis liquidae, D. Un-guentum Picis liquidae, L. D.