Garlic consists of the bulbs of Allium sativum, or common garden garlic, a native of Europe, but cultivated in most civilized countries. The bulbs, when taken from the ground, are dried, usually with portions of the stems remaining, by which they are tied into bundles, and thus brought into market.


The bulb of garlic consists of five or six smaller bulbs, commonly called cloves, each invested with a distinct coat, and the whole compactly arranged around the stem at its base, and inclosed in a white membranous covering, consisting of several thin, delicate layers. The substance of the minor bulbs, deprived of their coat, is whitish, moist, and fleshy, and contains a juice, which, on the addition of a little water, may be separated by expression. When these little bulbs become dry, as they do when very long kept, the medicine is wholly useless.

The odour of garlic is strong, penetrating, disagreeable, and characteristic; so much so that it serves as a standard of comparison for other odours, which, when thought to resemble it, are said to be alliaceous. The taste is bitter and acrid. These properties, as well as the medical virtues of garlic, are yielded to water, vinegar, or alcohol; but are impaired or destroyed by boiling. They depend on a peculiar volatile oil, which pervades the whole plant; but is especially abundant in the bulb. This is easily separated by distillation with water, leaving the residue quite inert. The oil, when pure, is a combination of carbon, hydrogen, and sulphur, constituting, according to Wertheim, the sulphuret of a compound radical denominated allyl, which consists of carbon and hydrogen (C6H5.). After exposure to the air it contains oxygen.

Effects on the System

Garlic is a local and general stimulant, operating directly upon the part to which it may be applied, and, through the absorption of its active principle, upon the circulatory and nervous systems, and the various secretions. Its influence upon the nervous centres, though very decided, and quite sufficient to allow it to rank in the present class of medicines, has not, I think, been so prominently noticed by pharmacological writers as it deserves to be. It agrees, too, with the nervous stimulants in having no tendency to disturb the special cerebral functions.

Moderate doses warm the stomach, excite the appetite, and facilitate digestion. In a short time the frequency of the pulse and general warmth are somewhat increased; and the patient feels an agreeable excitement, which, though little noticed, contributes, I have no doubt, to the favour in which it is held as a condiment, notwithstanding its originally very repulsive odour and taste, by vast numbers of people, indeed by whole nations in some parts of the world. Through its influence on the secretions, it acts as an expectorant, sometimes as a diuretic or diaphoretic, according as it is directed by circumstances preferably to the kidneys or the skin, and also as an emmenagogue. It is said occasionally to prove anthelmintic. Too largely taken, it causes uneasiness of stomach, sometimes even nausea and vomiting, occasionally purges, and is capable of producing a febrile state of system, with headache, quickened pulse, heat of skin, etc. Applied to the skin it acts as a rubefacient, and will sometimes vesicate.

All these effects it owes to the volatile oil, which is absorbed with great facility, and rapidly pervades the whole system. Its absorption is proved by the odour it imparts to the breath, perspiration, urine, and even the secretions from the surface of ulcers. In the lower animals, it affects the milk and the flesh with its peculiar properties of smell and taste. The absorption takes place not only from the stomach, but readily also from the rectum, and even from the skin. Garlic poultices applied to the soles of the feet will sometimes communicate their odour to the breath. The oil, therefore, though quickly entering the circulation, has a tendency to leave it rapidly, and, as it passes out through the different emunctories, stimulates them into an increase of their several functions.

In its whole medicinal character, garlic bears a considerable resemblance to assafetida, though perhaps somewhat more stimulant locally and to the circulation, and somewhat less so to the nervous system.

Therapeutic Application Garlic has been used as a condiment and medicine from times immemorial. Some of its most beneficial applications are grounded upon its properties as a nervous stimulant; and these are to be particularly noticed here. Its uses as a stimulating expectorant and diuretic will be referred to, under the heads of those cla-respectively.

As a stimulant to the stomach it is useful in debility of that organ, enabling food of difficult solubility to be digested more readily, and more comfortably to the patient. It is also an excellent carminative, producing the expulsion of flatus, and relieving spasmodic pains which its presence is apt to occasion, whether in the stomach or bowels. But as the expelled air is impregnated with the oil, the eructations are apt to be offensive, if not to the patient, at least to others in his vicinity.

One of the most useful effects of the medicine is to relieve the various disturbances of the nervous system which are so apt to attend the febrile diseases of children, such as restlessness, wakefulness, vague general uneasiness, twitchings of the muscles, starlings, and convulsions. For this purpose it is almost always used externally, being applied in the form of poultices to the feet, and as a lotion to the spine, made either by infusing the bruised bulbs for a short time in hot brandy, or by incorporating the expressed juice with oil or lard. The reader will observe that it is used here not merely as a revulsive agent, in which capacity it is inferior to mustard and other rubefacients, but in reference to the absorption of the oil, and its operation upon the nervous centres. It often most happily quiets the disturbance, and promotes sleep by correcting the state of the nervous system which prevented it.

In the advanced stage of the inflammatory diseases of children, and especially the pectoral, there is often a prostrated condition of the nervous centres, which very injuriously complicates the case. I have already, under the head of assafetida, called attention to this condition, and pointed out how it may be recognized, especially as attendant upon advanced bronchial and pulmonary inflammations. Garlic is scarcely inferior as a remedy to assafetida in some of these cases. I have used it often, and am quite sure with much benefit. It is not merely as an expectorant that it operates. It stimulates the nervous centres, and enables them to supply the necessary support to the functions of respiration and circulation, which are failing for the want of it. The remedy is especially useful, when, with this debility of function, there is also spasmodic complication, as in the affections referred to occurring in the advanced stages of hooping-cough, or in asthmatic children. I have usually employed it, in these cases, internally, in the form of syrup.

In almost all the spasmodic and convulsive complaints of children, whether affecting the alimentary canal, the chest, or the external muscles, or occurring as original affections, or as attendants on other diseases, garlic may be used externally, in the form of lotion or poultice; the application being made along the spine in convulsions, and both there and over the organ affected in internal spasms. The only contraindication would be high vascular congestion or inflammation in the nervous centres.

In mild cases of hysteria, especially when affecting the stomach and bowels, as in spasmodic pains, flatulent discharges, borborygmi, etc., garlic is often useful, though not unfrequently objectionable in consequence of the odour imparted to the breath. In all hysterical affections, it may be freely employed externally.

The medicine was formerly used in intermittent fever; but has been abandoned since the discovery of Peruvian bark.

As a topical application to the ear, it has been used advantageously in atonic deafness. For this purpose, a small piece of raw cotton may be impregnated with the juice, and introduced into the external meatus. If it irritate too much, the juice should be diluted.

Applied in the shape of a large cataplasm to the hypogastrium, it has been recommended in retention of urine from debility of the muscular coat of the bladder, and incontinence from weakness of the sphincter.

As an anthelmintic it has enjoyed some credit, being used by the mouth, and, in the instance of ascarides, by the rectum.

As a resolvent in indolent tumours, and a stimulant in chronic palsy and rheumatism, it has been employed locally in the form of lotion or poultice.


The dose of garlic, in substance, is from half a drachm to one or two drachms for an adult. It may be given in the shape of pills, or bruised and mixed with syrup or other vehicle as an electuary, or in the state of the unprepared clove or small bulb, either whole, or cut into pieces of convenient size for swallowing. But neither of these forms is adapted to children.

The most convenient preparation for internal use in the case of children is the syrup. This may be made extemporaneously by bruising the cloves, adding a little water, so as to enable the juice to (low out, then expressing, and mixing the liquid obtained with twice its weight of sugar. There is an officinal Syrup (SyRupus Allii, U. S.), which is prepared by first forming an infusion with vinegar, and afterwards incorporating this with sugar. The dose of either preparation for a child a year or two old is a fluidrachm, which may be repeated every hour or two, in acute cases.

For external use, cataplasms are made by thoroughly bruising the garlic, and incorporating it with the bread and milk poultice, or mixing it up with flaxseed meal or other adhesive powder, and hot water.

Lotions may be made by bruising the garlic, and heating it with proof spirit, which may then be applied by means of flannels wet with it, or by gentle friction.

A liniment may be prepared by incorporating the expressed juice with olive oil or lard.

A boiling heat should not be employed in the preparation of garlic, as it has the effect of driving off the oil.

Other species of Allium have effects analogous to those of A. sativum. The native garlic of our fields might probably be substituted without disadvantage. The onion (A. Cepa) and the leek (A. Porrum) have similar properties, but are much weaker. Nevertheless, a syrup made with expressed onion juice and sugar will be found useful in some of the pectoral affections, in which garlic has been recommended.