Camphora (U. S. P.)—Camphor.

Photo: Cinnamomum camphora. Preparations: Compound Mixture of Camphor - Camphor Cerate - Camphor Water - Compound Powder of Camphor - Camphor Ointment - Camphor Liniment - Compound Liniment of Camphor - Compound Pills of Camphor - Spirit of Camphor - Camphorated Mixture of Oils - Camphorated Soap Liniment - Compound Tincture of Serpentaria
Related entry: Lindera.—Spice-Bush - Cinnamomum.—Cinnamon - Laurus.—Laurel

"A stearopten (having the nature of a ketone) obtained from Cinnamomum Camphora (Linné) Nees et Ebermaier, and purified by sublimation (U. S. P.); (Laurus Camphora, Linné; Camphora officinarum, C. Bauhin)."
Nat. Ord.—Laurineae.
COMMON NAMES: Laurel camphor. (Tree) Camphor laurel.
ILLUSTRATION: Bentley, and Trimen, Med. Plants, 222.

Botanical Source.—The Cinnamomum Camphora is a large tree with lax, smooth branches. The leaves are evergreen, alternate, on long, slender, smooth petioles, somewhat coriaceous, oval, acuminate, attenuate at the base, bright-green and shining above, paler beneath, triple-nerved, with a sunken gland at the axils of the principal veins, projecting at the upper side and opening by an oval pore beneath. The flowers are small, smooth, yellowish-white, in axillary and terminal, naked corymbose panicles. The leaf-buds are scaly. The fertile stamens are 9 in 3 rows; the inner with 2, compressed, stalked glands at the base; the anthers 4-celled; the outer ones turned inward; the inner ones outward. Three sterile stamens are placed in a whorl alternating with the stamens of the second row; 3 others are stalked, with an ovate glandular head. The fruit is placed on the obconical base of the calyx (L.).

History.—Camphor, obtained from the Cinnamomum Camphora, and, in the crude state, is imported into this country, principally from Canton, where it undergoes purification by sublimation, before it is in a state adapted to medicinal use. The camphor tree inhabits the eastern and warmer latitudes of Asia. It thrives in warm countries and is cultivated by the Italians for ornamentation. It is an aromatic tree, all parts of it yielding the odor and giving the taste of camphor. Camphor is obtained in Japan by cutting the wood, roots, etc., of the tree in small pieces, boiling them in water, in large iron stills, fitted with earthen heads, containing straw cones. The water is kept boiling for about 48 hours, the camphor sublimes and concretes upon the straw in the head, in the form of a gray powder. It appears in commerce as whitish, dry, granular cakes, slightly tinged with red, and is known as Japan camphor, or Tub camphor, on account of being imported in a double tub. It was once commercially known as Dutch camphor. The Chinese pursue a different process. They steep the chopped branches in water, then boil it, continuing the ebullition until a stick placed in the fluid will, when cooled, be covered with the camphor. The liquor is then strained, and by cooling, the camphor solidifies. This is then placed alternately in layers, with powdered dry earth, in a copper vessel, over which another one is placed, and the camphor, being sublimed by heat, attaches itself to the upper inverted vessel. It is of a dirty grayish color, and is known as impure or crude camphor. Though prepared by the Chinese and known as Chinese camphor, it is manipulated in Formosa. None is made in China. It sometimes appears in the market like the preceding in appearance, but oftener of a darker hue, in smaller particles, and in a moist condition. It is packed in chests, covered inside with sheet-lead or tin, and is known as Chinese camphor, or Formosa camphor. In Formosa, camphor is also prepared by allowing the camphorated steam to collect on earthen receivers placed over the vaporizing troughs. Camphor is now refined in this country. Vessels similar to the bombaloes of Europe (large globular glass vessels), are sometimes used, differing, however, from the European apparatus in being made in sections, so that they can be readily taken apart and the camphor removed. To remove the sublimate from the bombaloes (of Europe) the latter must be broken. It may also be sublimed slowly and cautiously from retorts into a receiving chamber, as "flowers of camphor," a fine crystalline state which, by powerful pressure, may be made to form cakes. Japan, since the acquisition of Formosa, now has a monopoly of Chinese camphor.

The camphors are closely related to the different varieties of turpentine. Two species are known in the East, viz.: Borneo camphor (C10H18O), obtained from a very large tree, the Dryobalanops Camphora, Colebrooke, which is so highly prized by the natives that it rarely finds its way to our markets; and the Laurel camphor (C10H16O), from the Cinnamomum (Laurus) Camphora, and which is the ordinary camphor of commerce. Many other plants furnish camphor by oxidation of their essential oil, as lavender, rosemary, marjoram, pennyroyal, peppermint, feverfew, etc. Amber and the oils of valerian, sage and tansy, also yield it when treated with nitric acid.

Description.—"White, translucent masses, of a tough consistence and a crystalline structure, readily pulverizable in the presence of a little alcohol, ether, or chloroform; having a penetrating, characteristic odor, and a pungently aromatic taste. Specific gravity: 0.995 at 15° C. (59° F.). Very sparingly soluble in water, but readily soluble in alcohol, ether, chloroform, carbon disulphide, benzin, and in fixed and volatile oils. When camphor is triturated, in about molecular proportions, with menthol, thymol, phenol, or chloral hydrate, liquefaction ensues. It melts at 175° C. (347° F.), boils at 204° C. (399.2° F.), and is inflammable, burning with a luminous, smoky flame. On exposure to the air it evaporates more or less rapidly at ordinary temperatures, and, when moderately heated, it sublimes without leaving a residue. Camphor should be kept in well-closed vessels, in a cool place"—(U. S. P.).

Camphor is somewhat unctuous to the touch and, besides being pungent to the taste, it imparts an after-sense of coolness. It is so tough and elastic as to almost defy pulverization, which may be readily accomplished, however, by adding a few drops of alcohol or any of the agents above mentioned. Besides the above-named solvents, acetone dissolves it. It requires about 1300 parts of water for solution; sugar, magnesia, carbonic acid, corrosive sublimate, or spirit of nitrous ether render it more soluble in water. Resins and fats, when heated with it, unite in all proportions. Three isomeric modifications of camphor are known; they can not be distinguished from each other, except by their action upon a ray of polarized light; one of the varieties produces rotation of the ray to the right; the second variety produces left-handed rotation; whilst the third has no sensible effect upon polarized light. The common camphor of commerce, and that obtained by the action of nitric acid upon borneéne, is the right-handed modification. The camphor contained in the oil of Pyrethrum (Matricaria) Parthenium exerts a left-handed rotary action upon a ray of polarized light (Chautard); whilst, according to Biot, the camphor deposited by oil of lavender is destitute of any such rotary effect upon a polarized ray. By the application of polarized light, the smallest portion of natural camphor may be distinguished from the artificial camphor (hydrochlorate of camphene). If small fragments of each be placed separately on glass slides, and a drop of alcohol added to each, they dissolve, and speedily recrystallize. If the crystallization of the natural camphor be watched by means of the microscope and polarized light, a most beautiful display of colored crystals is seen, while with the artificial camphor nothing of the kind is witnessed. Camphor is lighter than water, and keeps up a constant rotary motion when small pieces are placed on that fluid.

When camphor is triturated with dragon's blood, guaiacum, galbanum, or asafoetida, the mixture preserves the pilular consistence indefinitely. With benzoin, tolu, mastic, and ammoniac, the mixture becomes soft when exposed to the air. With olibanum, gamboge, euphorbium, amber, and myrrh, the mixture remains pulverulent, though grumous. Asafoetida, galbanum, sagapenum, tolu, dragon's blood, olibanum, mastic, benzoin, tacamahac, guaiacum, and ammoniac, destroy to a greater or less extent the odor of camphor (M. Planche).

Chemical Composition.—The class of substances known as camphors, of which Japan camphor (C10H16O) is a representative, are products of oxidation of the group of hydrocarbons, known as terpenes. These are mostly all isomers of the formula C10H16, and, in turn, are hydrogen addition products of the hydrocarbon, cymol (cymene) (C10H14), or para-methyl-normal-propyl-benzene, having the graphic formula C6H4.(CH3).(C3H7).

Japan camphor may be converted into cymol by distillation with zinc chloride, or with phosphoric anhydride, which agencies abstract from camphor the elements of water, thus: C10H16O - H2O = C10H14. On the other hand, camphor may be obtained (in small amounts) by the oxidation of terpenes. When heated with iodine, ortho-oxycymol (carvacrol), an isomer of thymol is formed. These various reactions point to the following graphic formula for Japan camphor:

C3H7.CH < /CH2.CO\ > C.CH3.

Borneol (C10H18O), the camphor obtained from Dryobalanops Camphora, stands to Japan camphor in the simple relation of a secondary alcohol to a ketone. Consequently, borneol, by mild oxidation, yields Japan camphor, and from the latter, inversedly, Borneo camphor may be obtained by reduction with sodium in alcoholic solution. When Japan camphor is heated with nitric acid on a boiling water-bath, camphoric acid (C10H16O4) is formed; upon continued oxidation, camphoronic acid (C9H12O5) results. When treated with concentrated sulphuric acid, Japan camphor yields a black solution, from which, upon dilution with water, an oily body, camphene (C10H16), is precipitated. This substance, which is an isomer of the terpenes, forms, with hydrochloric acid, a crystalline compound, which has the smell of camphor, and is known as artificial camphor. It is obtained by passing into oil of turpentine dry hydrochloric acid gas and cooling the compound formed. Artificial camphor melts at 125° C. (257° F.) and boils at 210° C. (410° F.).

The camphresinic acid of Schwanert (1863) has been shown to be a mixture of camphoric and camphoronic acids. Oxycamphor (C10H16O2) in white, acicular crystals, possessing the characteristic taste and odor of camphor, results from treating camphor with the weaker oxidizing agents (notably hypochlorous acid), and acting upon the bodies thus formed with a solution of caustic potash in alcohol (Wheeler, 1868). With bromine, camphor forms unstable garnet-red crystals, having the composition C10H14OBr2, which yield, on being heated to between 80° and 90° C. (176° to 194° F.), an amber liquid, and evolve hydrobromic acid. On cooling, the liquid congeals, yielding crystals of monobromide of camphor, which may be purified by means of boiling alcohol. Chlorine also unites with camphor, forming monochlorine and dichlorine camphors, while iodine forms with camphor a substitution product.

ACIDUM CAMPHORICUM.—Camphoric acid (C10H16O4). Camphoric acid is an oxidation product from boiling camphor and nitric acid, or permanganate of potassium, usually the former. It may be prepared by heating camphor with 10 times its weight of concentrated nitric acid. It presents odorless needle-like crystals, having a faintly acid taste. It is soluble in boiling, but very sparingly soluble in cold water. Fats, essential oils, ether and alcohol also dissolve it. It is a bibasic acid, fuses at 70° C. (158° F.), and may be rendered anhydrous by sublimation. There are 3 isomeric modifications of it, determined by their action upon a ray of polarized light.

Action, Medical Uses, and Dosage.—In large doses camphor is a narcotic and irritant; in small ones, sedative, anodyne, antispasmodic, diaphoretic, and anthelmintic. Very small doses stimulate and large doses depress. Large doses cause oesophageal and gastric pain, vomiting, slow and enfeebled and subsequently intermittent pulse, dizziness, drowsiness, dimness of sight, pallid, cold skin, muscular weakness, cyanosis, spasms, muscular rigidity, and convulsions. Several deaths have resulted from its use, other circumstances contributing somewhat to the fatal issue, but cases of death in a healthy individual have been reported. Mental confusion may follow its excessive use. Its effects in small doses are transient, but are not followed by depression or exhaustion. It exerts an influence on the brain and nervous system, exhilarating and relieving pain, is an excitant to the vascular system, and irritates mucous tissues which are in proximity with it. When given in the solid form, it is capable of producing ulceration of the gastric mucous membrane. It is used to allay nervous excitement, subdue pain, arrest spasm, and sometimes to induce sleep. In the delirium, watchfulness, tremors, and starting of the tendons in typhoid conditions, it is of much utility as a nervo-stimulant. Occipital headache, from mental overwork, is relieved by small doses, and the external application of camphor. Large doses (grs. xx) are required in maniacal excitement. In inflammatory affections, as remittent and intermittent fevers, acute rheumatism, etc., it acts beneficially as a diaphoretic and sedative; and is also valuable in gout, neuralgia, dysmenorrhoea, after-pains, puerperal convulsions, and painful diseases of the urinary organs, acting as a sedative, anodyne, and antispasmodic. It is often advantageously combined with opium in chordee, and hysteric nymphomania, and all irritations of the sexual organs. It relieves the strangury caused by the use of cantharides. By some physicians it is said to act as an aphrodisiac, exciting the reproductive organs, causing considerable heat in the urethra, and nocturnal emissions; others, again, use it as an ant-aphrodisiac, and to diminish urino-genital irritation. For the first purpose small doses are effectual; for the second, large sedative doses are requisite. It is said to be an antidote to poisoning by strychnine, and has been used in poisoning from illuminating gas. An oleaginous injection of camphor in the early stages of gonorrhoea often allays urethral irritation, as well as the tenesmus caused by thread-worms, etc., when injected into the rectum. It enters into many embrocations and liniments for rheumatic, neuralgic, and deep-seated pains, cynanche tonsillaris, contusions from blows, sprains, chilblains, chronic cutaneous diseases, and as a stimulant for indolent and gangrenous ulcers. The itching of smallpox pustules is said to be relieved by it. It has been found beneficial in asthma and spasmodic cough, and the powder may be used as a snuff for the relief of nervous headache, and catarrh in its commencing stages. Camphor is a remedy of marked value in many bowel troubles, and is usually used in combination with pain-relieving agents for that purpose. Evidence is strong in its favor as an agent in Asiatic cholera. The nervous manifestations of la grippe seem to be controlled by small doses of camphor. Spirits of camphor and camphorated oil are well known to allay the pain attending acute mastitis, and to check the lacteal secretion. The spirit, on cotton, sometimes allays toothache. The best form of using an aqueous solution of this agent is the aqua camphorae. The administration of opium will best neutralize the evil effects of an overdose of camphor. Small and repeated doses of alcohol may also be given. Dose of the powder, 1 to 10 grains; aqua camphorae flʒii to flʒiv; spirits of camphor, 1 to 30 drops.

CAMPHORIC ACID is sedative and antiseptic. It has been lately advocated as an efficient remedy for the night-sweats of pulmonary consumption. It is considerably employed in 1 per cent solution in catarrhal diseases, both acute and chronic, good results being reported from its use in sore throat, acute nasal catarrh, acute bronchitis, irritable bladder, cystitis (acute and chronic), strangury, enuresis, and nocturnal seminal emissions. It has made some impression for good in spasmodic states, as epilepsy, hysteria, and chorea. For local use it may, if desired, be combined in solution with borax, or boric acid. The dose is from 10 to 25 grains in solution or in capsules. Solutions of from 1 to 4 per cent are locally employed.

Specific Indications and Uses.—"Insomnia and restlessness, the pulse being soft and tongue moist; diarrhoea" (Scudder). Low grades of inflammation and fevers, particularly typhoid, with great restlessness, morbid watchfulness, muttering delirium, subsultus, dry skin, and quick, irritable pulse (Locke); strangury; urination frequent, difficult, and tenesmic. For specific use 1/8 to 1 grain doses. In minute doses in burning pain in stomach; dizziness, nausea, and vomiting: weak, husky voice; cyanotic countenance, with cold extremities.

Related Camphors and Camphor Oils.—Many essential or volatile oils, when subjected to distillation, yield a product liquid at ordinary temperatures, which is a hydrocarbon (usually of the terebenthene class or series [C10H16]), often termed an elaeopten, and a portion solid at ordinary temperature, an oxidation product known as a stearopten. The latter often exists as a vegetable exudate, or may be derived from vegetation by proper treatment. It has a higher boiling point than the elaeopten. The stearoptens are known under the general and elastic term camphors, and have the general composition C10H16O, and, though obtained from many plants, it is altogether probable that they are identical with laurel camphor.

BORNEO CAMPHOR. Camphol, Borneol, Malayan camphor, Camphyl alcohol, Sumatra camphor, Barus camphor, Dryobalanops camphor.—Composition C10H18O. Found under the bark and in fissures of the trunk of Dryobalanops Camphora, Colebrooke (Dryobalanops aromatica of Gaertner), of the natural order Dipterocarpaceae. India, Sumatra, and Borneo.

Borneo camphor contains 2 atoms more of hydrogen than common camphor. It is an alcohol yielding ethers with acids. It requires a heat of 198° C. (388° F.) to melt it, is less volatile, but denser and harder than ordinary camphor; it boils at 211.6° C. (413° F.). Its smell, solubility, and general appearance are like those of common camphor, and it exerts a somewhat more feeble right-handed rotary action upon polarized light. On account of its crystallizing in the regular system, however, it is stated by Descloizeaux (1870) and confirmed by Flückiger (1874), that it displays no colors under the polarization microscope. Its taste differs from that of ordinary camphor in being both camphoraceous and hot and peppery. It crystallizes in small, transparent, regular, colorless, 6-sided prisms and is converted into ordinary camphor when gently heated with nitric acid of moderate strength, which causes a loss of 2 atoms of its hydrogen. It is naturally associated with an oil termed bornéene (C10H16), which is isomeric with oil of turpentine and with valerene, and which is removed by distillation in order to obtain the camphor free from it. Dryobalanops camphor is a little heavier than water and falls to the bottom, while the laurel variety floats. It does not possess the gyratory movements of the laurel camphor; has generally a tabular form; an amberous odor, and is usually accompanied with foreign substances, among which are amorphous resin, neither acid nor volatile, but which, when heated, gives out an odor of colophony. Borneol may be made artificially by hydrogenating laurel camphor. Borneo camphor is sold at an excessively high price in the East and is never found in our markets.

NGAI CAMPHOR, Blumea camphor.—A camphor identical in composition (C10H18O) with borneol, but different in turning the ray of polarized light, as much to the left as borneol does to the right; derived from a southeastern Asia composite plant, known to the Chinese as Ngai, and to botanists as Blumea balsamifera, De Candolle. By oxidation with nitric acid it yields a camphor identical in composition with laurel camphor (C10H16O), but still retaining its laevogyre behavior. It is prepared in Canton and the Hainan Isle, and used by the Chinese as a medicine and in perfuming choice Chinese inks. Its price being about tenfold higher than that of common camphor, prevents its occurrence in European and American commerce. Its physical appearance, after sublimation, is identical with that of borneol.

Blumea lacera is used in India as an insecticide. It yielded Dymock, a pale-yellow essential oil of extraordinary left-rotating power. Its density, at 26.6° C. (80° F.), is 0.9144.

CHAMPACA CAMPHOR.—Champacol (C17H30O). A new camphor from champaca wood. Isolated by Merck (1893).

FORMOSA CAMPHOR OIL. Camphor oil of Formosa, Oleum camphorae (U. S. P., 1870), Camphor oil.—This oil is drained off the crystals of crude camphor in the preparation of the latter, and prepared to some extent when camphor is refined. It is a brownish-colored liquid, holding in solution quite a quantity of camphor, which crystallizes out of the oil when the latter is subjected to a reduced temperature. It has the taste of common camphor and a sassafras-like, odor, by which it maybe readily distinguished from Borneo camphor oil (Pharmacographia). It has a density of 0.940; its boiling point is near 180.5° C. (357° F.). Like laurel camphor it is dextrogyre in behavior. Flückiger (Pharmacognosie, 1891) mentions as the constituents of this oil the following: Dipentene (cinene) (C10H16), a hydrocarbon boiling at 182° C. (359.6° F.), capable of yielding addition products with bromine (C10H16Br4), fusing point 126° C. (245.2° F.); also with hydrochloric acid (C10H16[HCl]2), and with water (C10H16[H2O]3). Besides, Schimmel & Co. (Report, Oct., 1888) made known the following constituents: Pinene, phellandrene (both C10H16), cineol (C10H18O), safrol, eugenol, and a considerable amount of a hydrocarbon, identical with that obtainable from cubebs.

BORNEO CAMPHOR OIL. Camphor oil of Borneo, Sumatran camphor oil, Bornéene.—An oil derived from the tapped or felled trees (Dryobalanops Camphora, Colebrooke) which yield Borneo camphor. It has been said to be secreted in such great quantities in old trees, and to exert such great pressure as to disrupt the trunk of the tree, the bursting causing a report like that from a cannon. A similar phenomenon is said to take place in the tree furnishing copaiva balsam (Pharmacographia). Bornéene (C10H16) is isomeric with pure turpentine, and is a volatile, viscid, brownish-red oil, composed of borneol and resin dissolved in bornéene, a liquid having a turpentine-like odor, and identical with the valerene of valerian oil. It does not deposit Borneo camphor on standing even when subjected to a very low temperature. In its optical properties it is dextrogyre.

Camphor Preparations.—VINUM CAMPHORATUM. Wine of camphor.—This is a turbid, whitish fluid, prepared according to the German Pharmacopoeia, by dissolving 1 part of camphor in 1 part of alcohol and incorporating gradually, and with agitation, 3 parts of mucilage of acacia and 45 parts of white wine. Its use is the same as that of spirits of camphor, and it must he shaken before dispensing and administering.

CAMPHORA CARBOLISATA. Camphora phenolata, Carbolated camphor, Phenol camphor, Camphorated phenol.—An oily or colorless liquid, having a camphoraceous odor, practically insoluble in glycerin and water, but soluble in alcohol, fixed oils and ether. Hager prepares it by dissolving 100 parts of camphor and. 36 parts of carbolic acid in 4 parts of alcohol: Bufalini, by allowing 2 parts of camphor and 1 part of phenol to liquefy. A local anaesthetic and antiseptic. Ten-drop doses of an olive-oil solution have been given in catarrh of the stomach, and the same applied has arrested erysipelas. Wounds, ulcers, boils, and herpetic skin affections, as well as diphtheric membranes, have been painted with it, and uterine leucorrhoea locally treated with it, with asserted relief. It is said to relieve the pain of ingrown nails and dental caries.

CAMPHORA SALICYLATA. Salicylated camphor.—Heat, by means of a water-bath, to 90° C. (194° F.), a mixture of 65 parts of salicylic acid and 84 parts of camphor until liquefaction takes place (Guirleo). An oily fluid, devoid of color, and becoming a solid opaque mass which, when triturated, assumes an unctuous consistence. Fixed and volatile oils dissolve it, while it is much less soluble in water or glycerin. Useful, locally, in syphilitic phagedena and ulcerations. Suppositories are sometimes made of it by combining it with 10 to 15 parts of petrolatum, with a little paraffin added to give hardness.

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.