Terebinthinae Oleum-Oil of Turpentine. The oil distilled from the oleo-resin (turpentine), obtained from Pinus palustris, Pinus Taeda. and sometimes Pinus Pinaster.

Characters.-Limpid, colourless, with a strong peculiar odour, and a pungent and bitter taste. Sp. gr., 0.864. Mixes with other volatile and fixed oils, and dissolves resins, wax, sulphur, phosphorus, and iodine. Solubility, 1 in 10 of rectified spirit; remains transparent with chloroform.

Composition.-The oleo-resin, common turpentine, as it flows from trees, is an impure solution of resin in the officinal volatile oil. The oil of turpentine, C10H16, with the characters just described, readily absorbs oxygen, and is converted into the resin, which thus increases with the exposure of the oleo-resin to air. When the latter is distilled, the volatile oil passes over, leaving the resin behind. Oil of turpentine is isomeric with a number of volatile oils already met with in the materia medica.

Dose.-10 to 30 min.; as an anthelmintic, 2 to 4 fl.dr.

Preparations.

1. Confectio Terebinthinae

Confectio Terebinthinae. 1, with Liquorice 1, and Honey 2. Dose, 60 to 120 gr.

2. Enema Terebinthinae

Enema Terebinthinae. 1 oz., with Mucilage of Starch 15 oz.: for one enema.

3. Linimentum Terebinthinae

Linimentum Terebinthinae. 16, with Camphor 1, and Soft Soap 2.

4. Linimentum Terebinthinae Aceticum

Linimentum Terebinthinae Aceticum. 1, with Acetic Acid 1, and Liniment of Camphor 1.

5. Unguentum Terebinthinae

Unguentum Terebinthinae. 1 in 2 1/8.

Action And Uses. 1. Immediate Local Action And Uses

Externally.-Applied to the skin or exposed mucous surfaces, turpentine is antiseptic and disinfectant, and produces a sense of heat and redness, followed by burning and vesication, the local circulation being stimulated, and the local nerves first irritated and then depressed. Turpentine is therefore in very extensive use as a local stimulant and counter-irritant: (a) In painful affections of a local kind, such as chronic rheumatism of muscles or joints, and neuralgia, in the form of the liniments, the resin plaster, and turpentine stupes, (b) In affections of deep parts, to act reflexly on the vessels and nerves ; for instance, to relieve bronchitis by being rubbed on the chest, meteorism by application to the abdomen as stupes, or affections of joints by inunction over them, {c) As a disinfectant and stimulant it may be applied to ulcers and wounds, the Unguentum Resinae being very useful for this purpose, whilst the pure oil may be applied to hospital gangrene. Turpentine is absorbed by the unbroken skin, and its action in meteorism may be partly accounted for in this way, as we shall see.

Internally.-Oil of turpentine with its characteristic taste, produces reflex salivation, and possibly in this way improves the digestion when given in small doses. Having reached the stomach it is, as externally, disinfectant, stimulant to the vessels, sedative to the local nerves, and reflexly stimulant, at least for a time. In a word, turpentine is a powerful carminative. It is but little given for this purpose, because unpleasant to the taste and often disagreeable in its own effects, and because we have abundance of other aromatic volatile oils, equally powerful, and without either of these drawbacks. See Caryophyllum, page 242.

Turpentine passes into the bowel, and may be found even in the colon (which may, however, excrete it also, as will be described). Here it acts reflexly as a stimulant to the muscular coat, causing contraction, expulsion of gas and faeces, and recovery of tone if it have been lost by tympanitic distension; and is also a disinfectant and vascular stimulant. In larger doses these effects proceed to purgation. It is therefore given in tympanites, either by the mouth or as the enema, especially when this is associated with constipation; and it has proved useful in some forms of diarrhoea and dysentery. It may also be advantageously added to enemata after haemorrhage from any part, being, as we shall see, haemostatic.

Turpentine proves to be an anthelmintic, and is given either by the mouth for the tape-worm, in doses of 1/2 to 2 fl.dr., which may certainly cause unpleasant symptoms; or as the Enema, for the thread-worm, an excellent method.

Another local application of oil of turpentine is to the respiratory organs, as an inhalation. The diluted vapour in steam should be used, or the pure vapour inhaled from a warm sponge, which may however be irritant. Turpentine enters the blood thus, but the chief action desired is a purely local one, to disinfect and stimulate the chronically inflamed or ulcerated surfaces of the lungs and bronchi, and correct the smell and irritant properties of the products. It is therefore used in gangrene of the lung, dilated bronchi, and other allied conditions.

2. Action On The Blood

Oil of turpentine is freely absorbed by all surfaces, and enters the blood unchanged. Thus introduced, it produces none of the rapidly fatal effects which follow its injection into the veins of animals, and which are referable in part to coagulation and its results. Probably, however, even in medicinal quantities, turpentine is partially oxydised at the expense of the blood.

3. Specific Action And Uses

Found unchanged in the tissues and organs, oil of turpentine sets up a series of symptoms, mainly depressant in their character, which follow the reflex stimulant effects already described as referable to its action on the nerves and vessels of the stomach. A full dose produces a feeling of languor, debility, nausea, dulness, sleepiness, and unsteady gait; a large dose may lead to coma. These sedative effects on the nervous system may account for the success of the empirical use of turpentine in painful affections such as neuralgia, especially obstinate sciatica.

At the same time the heart is disturbed by the oil, and the blood pressure decidedly falls. Here we may find the explanation, in part, of the unquestionable value of turpentine as a haemostatic. Of all the means of arresting internal haemorrhage, it frequently proves itself to be the most powerful: bleeding from the lungs, stomach, bowels, and uterus will often cease after a full dose of turpentine, when every other drug has failed. It appears to he specially useful in intestinal haemorrhage from typhoid ulceration. In all such cases the oil must be fearlessly exhibited, since life is at stake, a dose of 1/2 fl.dr. being followed every two hours by doses of 15 to 20 min.

The temperature is believed to be lowered by turpentine.

This substance is also a physiological antidote to phosphorus, and may be used (best in the form of the crude oil) either to prevent chronic phosphorus poisoning in workmen, or in small repeated doses in acute poisoning, after sulphate of copper. See Phosphorus (page 99) and Copper (page 65).

4. Remote Local Action And Uses

Oil of turpentine, like the volatile oils, is excreted, mainly as such, by the cutaneous and mammary glands, by the lungs and respiratory passages, by the kidneys, and possibly by the liver, biliary mucosa, and intestines. All these organs are influenced by the oil as it passes through them. Perspiration is slightly increased, and an eruption may appear on the skin. In the bronchial walls it acts as a vascular stimulant, and disinfects both these and their products; it might therefore be a valuable drug in chronic bronchitis, dilated bronchi, and gangrene of the lungs. Its effect as it passes through the kidneys accounts for the comparatively little use that is made of it in these and other diseases. Even in moderate doses it may produce symptoms of irritation and congestion of the renal organs, including lumbar pain, repeated painful ineffectual attempts at micturition, a sense of heat and spasm in the perineum, frequently with haematuria. "Whilst small doses cause diuresis, large doses may cause complete suppression. It may be occasionally used with caution in Bright's disease, and even in haematuria. Part of the turpentine is excreted as a fragrant violet-smelling body, and this and the unchanged portion exert a remote local effect as stimulants and disinfectants in the bladder and urethra, so that cystitis and gleet have been treated with the oil.

In passing through the biliary passages, turpentine is believed to prevent or dissolve gall stones. Its excretion by the colon probably contributes to its effect in emptying the bowel of gas and faeces.