The dried unex-panded flower buds of Caryophyllus aromaticus. Cultivated in Penang, Bencoolen, and Amboyna.

Characters. - About six lines long, dark reddish-brown, plump and heavy, consisting of a nearly cylindrical body surmounted by four teeth and a globular head, with a strong fragrant odour, and a bitter spicy pungent taste. It emits oil when indented with the nail.

Composition. - Cloves contain 20 per cent. of the officinal oil, tannic acid, and gum. Oil of cloves consists of eugenol (eugenic acid), C10Hl2O2, chemically resembling phenol (carbolic acid), and a turpentine. A crystalline body, eugenin, isomeric with eugenol, and a neutral body, caryophyllin, isomeric with camphor, can also be obtained from cloves.

Preparations.

1. Oleum Caryophvlli

Oleum Caryophvlli. Oil of cloves. The oil distilled in Britain from cloves. Colourless, when recent, becoming red-brown, with the odour and burning spicy taste of the clove. It is one of the few volatile oils heavier than water. Dose, 1 to 4 min.

2. Infusum Caryophylli

Infusum Caryophylli. 1 in 40. Dose, 1 to 2 fl.oz.

Cloves and Oil of Cloves are also contained in several preparations of other drugs.

Action And Uses

Cloves may be taken as the type of a great group of remedies, other members of which are orange, lemon, pimenta, cajuput, carui, dill, peppermint, and many more, which are met with in our systematic review of medicinal plants. This group is known as the aromatic essential oils, of complex and variable chemicalcomposition, but consisting as a rule of terpenes, mixed with camphors, resins, fatty and other acids, and different vegetable constituents. They are closely allied, on the one hand, to phenol (carbolic acid) and benzoic acid, and on the other to still more complex vegetable products, the balsams and gum-resins. Instead of dislocating the various members of the group of aromatic oils from their proper botanical position to discuss them together, we will describe their action and uses once for all under the present head, it being understood that what is said of oil of cloves applies to the other substances, with insignificant qualifications.

1. Immediate Local Action And Uses

Externally, the essential oil of cloves and allied substances closely resemble turpentine in properties. Thus, whilst preventing or arresting decomposition, they redden and inflame the skin, and cause for a time smarting pain, which gives place to local ansesthesia. Oil of cloves and other officinal fragrant oils are too costly to be used externally, except to scent liniments; but the concrete "oils," or solid constituents of the oils, of peppermint, thyme, eucalyptus, myrtle, etc. (stearoptenes), are excellent antiseptics, local anaesthetics, stimulants and counter-irritants and turpentine and camphor are common applications for these purposes. Such aromatic substances might be used to disinfect foul wounds and ulcers, and promote healing; to hasten the removal of chronic inflammatory products by increasing the local blood-flow, and thus to reduce swelling in or under the skin, the periosteum, or the joints; to relieve neuralgic and rheumatic pains, such as sciatica and lumbago, by dulling the sensibility of the nerves; and to act reflexly on deeper parts, for instance, the lung or heart, when applied to the skin over them as counter-irritants.

Internally. - In the mouth the aromatic oils of cloves and its allies act much as they do on the skin. Besides being antiseptic, they dilate the local vessels (? directly), and thus increase the circulation, heat, and nutrition, and may even cause inflammation. They irritate the nerves, causing pain associated with a sense of burning; but depression quickly follows, and local anaesthesia. Oil of cloves is a valuable application in toothache from dental caries, acting at once as an anodyne and disinfectant. At the same time, the nerves of taste and smell (flavour) are powerfully excited. Several results, of the first importance in digestion, follow these local changes, namely: (1) reflex salivation; (2) reflex flow of mucus; (3) reflex hyperemia of the gastric mucosa, a sense of hunger, and a flow of gastric juice; (4) stimulation of the appetite and increase of relish "by the pleasing flavour; and (5) in a word, increased desire for, enjoyment of, and digestion of food.

Aromatic oils are accordingly used very extensively in cookery, where the proper use of them constitutes an important portion of the culinary art. Those of them which are also bitter, such as orange, are taken with wines and spirits as various "aromatichitters," liqueurs, etc., to rouse or strengthen appetite and digestion before or during a meal. In pharmacy they are employed to correct the tastes of nauseous drugs; and therapeutically they are given in dyspepsia and debility along with most bitters to increase the saliva and gastric juice.

In the stomach, the effect of aromatics on the vessels and nerves is continued; and here it is generally described as carminative. Besides causing an increased flow of juice, by stimulation of the mouth, these substances are powerful stomachics in several ways. The vessels of the mucosa are dilated; the nerves of the same are first excited (causing a sense of heat in the epigastrium) and then soothed, thus relieving pain; the contents, if decomposing, as in dyspepsia, are partly disinfected. Their reflex influence is equally important. The muscular coat is stimulated, thus increasing the gastric movement, expelling flatulence, and relieving painful cramps, spasms, hiccup, and other forms of distress. Distant organs are also stimulated: the vigour of the heart increased, the blood pressure raised, and the spinal, medullary, and even cerebral centres temporarily excited, to the relief of low, hysterical, and "spasmodic" symptoms, very common in certain classes of females, as well as of more serious conditions, such as asthma, cardiac pain, and palpitation. Aromatics are thus general stimulants and antispasmodics.

In the intestines the aromatic oils may still be found partly unabsorbed, acting on the same structures as before, increasing the local functions, stimulating the intestinal movements, and expelling flatus. They thus relieve or prevent pain or spasm (colic), and provide us with valuable correctives of the griping tendencies of many purgatives. The constitution of the most important compound pills, powders, and laxative draughts should be studied in this connection, such as Pilula Rhei Com-posita, Pulvis Jalapae Compositus, and Mistura Sennae Compositus. Caryophyllum is slightly astringent, by virtue of its tannic acid.

2. Action On The Blood

The aromatic oils of cloves and its allies enter the blood as such, and whilst oxydised in part by the red corpuscles, leave the circulation mainly unchanged. Some of them are known to increase the number of white corpuscles, possibly by acting on the lymphatic glands or spleen.

3. Specific Action And Uses

The aromatic oils are rarely given in sufficient doses to produce definite specific effects on the tissues and organs. It may safely be assumed that in the main their action closely resembles that of turpentine, or that of camphor, respectively, as the one or the other compound is in excess in the particular drug. (See these substances.) Speaking generally, they are stimulant and antispasmodic; but let it be noted that a great part of this effect is reflex from the stomach, as described.

4. Remote Local Action And Uses

The aromatic oils are excreted by the kidneys, skin, bronchi, liver, and probably the bowels; and in passing through these structures stimulate and disinfect them. This subject is of the first importance in pharmacology, and will be best discussed under the head of turpentine, an oil which produces very marked remote effects. See Terebinthinae Oleum, page 346.