Cough, a violent, often involuntary, and souorous expiration, suddenly expelling the air through the contracted glottis. It is excited by any acrid substance, either chemically or mechanically applied to those passages through which the air enters. These are lined with a membrane so exceedingly sensible, that it cannot bear the mildest stimulus, such as a drop of cold water, without throwing the muscles serving for respiration, into a violent convulsion. Hence the air is expelled with a force sufficient to carry along with it the irritating substance; and thus a cough becomes not only useful, but indispensably necessary for the pre-. solvation of life 3 as this effort frees the lungs from every kind of sti-.

mulating matter, or foulness, which might otherwise be attended with suffocation. A cough is, there-lore, an almost inseparable compa-nion of every inflammation of the lungs, as well as every difficulty of breathing: nay, it frequently takes place, when the purest air enters an excoriated, sore, or too sensible windpipe, and its tender branches. It may also arise from too great an irritability of the nervous system, or even of some particular part, such as the ear ; from worms and impurities in the first passages ; obstructions of the ab-dominal viscera ; acrimony clogging the glands, and originating frequently from a catarrhal and scrophalous disposition ; hysteric weakness; accumulation of sharp humors in the lungs, etc.

From this view of the causes which produce coughs, it will not be expected that we should expatiate on the treatment of the complaint, under every form and variety of circumstances : we shall therefore consider it under the following heads:

I. The convulsive cough of infants, in general, proceeds from a foul and disordered stomach, in consequence of too viscid and superfluous food, such as porridge, puddings, cakes, gingerbread, confectionary, etc. It is accompanied either with a voracious appetite, or a total want of it ; difficulty of breathing, a tumefied hard belly : mausea, and often vomiting. The breath and excrements of such children are unusually fetid ; they seldom cough from the breast, but make effort-, to vomit, and throw up a viscid phlegm ; in cor quenee of which, they remain easy for a longer time than usual. Their tongue is always impure, and the cough increases in violence, after meals.

For the cure of this troublesome complaint, there are no better remedies than gentle emetics, and laxatives. A child under one year old, may occasionally take a large tea - spoonful of this mixture ; namely, syrup of squills and rose-water, of each one ounce; powdered rhubarb, four grains ; and ipecacuanha, two grains. The dose may be repeated every half hour, for three or four times, till it produces vomiting; and, in children two or three years of age, it may be somewhat increased, but never to exceed a dessert-spoonful. After the medicine has operated, a clyster, composed of milk and water, with a little oil and sugar, ought to be given, and repeated every other, or third day, while a sparing" diet should be strictly observed.

II. The convulsive cough of adult;, likewise arises from the disordered organs of digestion, and is frequently the constant lot of tipplers in spirituous liquors, and habitual drunkards. At its commencement there is little or no ex-pectoration ; and an inclination to vomit generally precedes a fit of coughing. - The treatment of this malady is similar to that of the same species in children; but, if the paroxysms should be so severe as to threaten suffocation, we ad vise, from experience, small doses of calcined zinc, from half a grain to one grain at a time, to be taken in a spoonful of luke-warm water, and to be repeated, if necessary, every five or ten minutes.

III. The catarrhal cough,which is the most cpmmon, and very frequent, especially in the winter ton : See Catarrh. Its immediate cause is a defluxion of hu vey the salival humour into the stomach. 3. To repeat it every time during the day, when, by a tickling in the throat, they apprehend the approach of a fit of coughing. By such practices, he observes, great benefit has been derived by himself and others. We are, however, inclined to think, that it will be useful only at the commencement of the complaint. And the Doctor likewise adds, that to a patient long afflicted with it, totally deprived of his appetite, and perhaps sunk down into a consumption, it is not so effectual, though always of some service. Those who cannot possibly swallow any kind of solid food, he advises, at least, to chew dry aliment, at the times before specified, and again to part with it: this expedient will considerably lessen the quantity of sali-val humour, and thus prevent, or shorten, many fits of coughing. ,

It is a common error, that all coughs may be cured by the usual mode of administering oily, diluent, and demulcent remedies. At first, indeed, such medicines may be serviceable, to sweeten the acrid humours then secreted, and to allay the irritation. But, as the compounds of oil, spermaceti, etc. easily turn rancid, and even in a fresh state impair the appetite, and affect the breast, we consider them as extremely precarious: hence we would prefer the chewing of the extract of liquorice, gum arabic, and similar substances, to all liquid preparations. If, however, the cough has made such progress, as not to yield to the treatment here alluded to, in this case we can confidently recommend the use of the following acid julep : Three ounces of sweet olive oil, two ounces of syrup of capillaire, one ounce of conserve of roses, and thirty drops of strong oil of vitriol; mix them properly, and take a tea-spoonful or two frequently. These ingredients form an excellent medicine for adults; but, for children, we would prefer a julep prepared of eight ounces of rose-water, four ounces of syrup of dry roses, and six drops of vitriolic acid ; to be taken by spoonfuls, as often as oc->n may require, especially if the cough be accompanied with thirst and febrile heat. In the latter cases, the julep should be diluted with sweet whey, which of itself is an incomparable beverage in catarrhal affections.

Lastiy, we cannot omit to insert in this place, a remedy which is highly praised by the late Dr. Un-ZER, of Hamburgh, and the physicians of that city, as being of inestimable value in all obstinate catarrhs, stagnations, and accumulations of humours in the breast; dry coughs; and severe bruises near the pectoral vessels, from which suppurations and ulcers may be apprehended. This medicine is a simple decoction of the Calaguala, a root lately imported from South America, and now universally preferred to the seneka or rattle-snake root, which was formerly used for similar purposes. Dr. UNzer directs two drams of the calaguala to be boiled in a quart of water, till the fourth part is evaporated, and to drink several cups of the strained decoction, instead of tea. When taken sufficiently strong, and for a proper length of time, it evidently ads on the skin and kidnies, by determining the noxious humours to those outlets. He cautions, how-ever, against a spurious species of that root, which is frequently sold by druggists, instead of the genuine ; and an account of which is* given by M. Galmetti, an Italian writer.

We have thus enlarged on the subject, because long - continued coughs generally lay the foundation of consumptive and other disorders, which annually deprive the community of thousands, whose lives might be easily preserved, if they had not neglected the first attack.

Cough, in farriery, a disease to which horses are very subject. When injudiciously treated, it is sometimes of long duration ; occasions loss of appetite, wasting of the flesh, and, ultimately, consumption. Of this malady there are two principal species : the one is loose, almost continual, and increases to a violent degree, upon the least motion; the other is short and dry, being preceded by a husky, hollow kind of wheezing, apparently arising from obstructed breathing, by the retention of fragments of hay, or corn, in the passage. The latter is usually called an asthma, for which mercurial purges are recommended; - the animal should first be bled repeatedly, and in small quantities, till the inflammation and irritability of the glands are allayed ; and the blood so attenuated by the constant use of nitre, as to facilitate the circulation through the finer vessels of the lungs. This operation being performed, a ball consisting of the following ingredients should be given, according to Mr. Taplin, every morning, for a fortnight or three weeks.

Detergent pectoral balls: Take of castile soap, aniseed, and liquorice powder, each 5 oz.; Barbadoes far 6oz., gum ammoniacum 3oz., balsam of Tolu loz., and honey sufficient to make a mass ; which must be divided into twelve balls. - Should the animal not recover from this course, he must be again bled, and treated with mercurials.

With respect to the long, loud, incessant, hollow cough, which increases on the least hurry in ex-ercise, the first step is blood-letting; then a mash should be given, consisting of equal parts of bran and oats, into which, while hot, 4 oz. of honey and 2 oz. of nitre, must be stirred and dissolved. This mash must be repeated, without intermission, every night and morning, and a ball prepared of Turkey figs, Spanish liquorice, aniseed, and liquorice - powder, each 4 oz.; carraway-seeds, elecampane and anisated balsam, each 2 oz.; saffron, ground ginger, and oil of aniseed, each 6 drams ; and the requisite proportion of honey to form the whole into a paste, which should be divided into 12 balls, one of which is to be given every morning.

These balls, says'Mr. Taplin, are powerful, cordial, and restorative ; they promote glandular excretion, warm, and stimulate the stomach to an expulsion of wind ; enliven the circulation, and invigorate the whole frame. - It will, perhaps, be useful to observe, that some young horses are subject to coughs, when cutting their teeth; in such case, it is necessary to bleed, and give them warm mashes, which, in general, will effectually remove, the disorder.

Cough, in cattle, a disease called the husk, to which young bullocks are liable. In this dangerous affection, the wind-pipe and its branches are obstructed with small taper worms. It is by farmers generally considered as incurable, though we are of opinion, that fumigations with cinnabar, or with fetid substances, such as tobacco, hartshorn shavings, feathers, etc. might occasionally prove of service, especially if they be cautiously administered by means of clysters.

Cough. - Calves are liable to take frequent colds, especially if they be exposed to the vicissitudes of the weather, before they acquire sufficient strength to undergo the changes of this climate : the consequence is a cough, that frequently proves fatal, if it be neglected. - For curing this malady, the following recipe is given in the " Cardiganshire Landlord's Advice to his Tenants-;" Bristol, 1800: Let half a table-spoonful of spirit of turpentine be poured into the animal's nostrils, which must be held upwards, in order that the liquor may flow into the throat: at the same time, the nose ought to be smeared with tar, and the calf be kept in the house for a few hours : this treatment should be repeated as often as the cough is troublesome.