Keeping the part constantly wet with Goulard's lotion is also very effectual.

The intertrigo occurring behind the ears in infants generally requires little more than scrupulous attention to cleanliness, and the interposition of a singed rag to absorb moisture. Such sores as form in this situation, if kept constantly moistened with a weak solution of the acetate of lead, will usually heal rapidly. Most authors, however, caution us against drying them up, dreading from such imprudence the occurrence of ophthalmiæ, inflammations of the brain, stomach, or intestines, or some other serious complaint; but by taking care to induce a somewhat freer state of the bowels whilst healing these sores, and by slightly reducing the quantity of the child's food, we shall probably in most instances obviate all dangers from this source. In all cases, however, we should endeavour, by attention to cleanliness, to prevent the affection ever going so far that either its existence should be productive of much inconvenience, or its removal of much risk. The advocates of the prophylactic virtues of such sores should be made aware that they often become in themselves, from their painfulness and fœtor, and the swelling of the cervical glands which they induce, very troublesome ailments; and that they have even, in some cases, been known to prove fatal by the extension of the inflammation to the internal ear, and to the brain. The sores, too, occasionally become livid and gangrenous, and the child sinks even before the sloughs have separated-a termination which has been mentioned by Burns, who in such cases dwells on the necessity of directing all our efforts to supporting the strength, regulating the bowels, and counteracting the tendency to mortification by the application of camphorated spirits, the fermenting poultice, &c. Where intertrigo makes its appearance in the folds of the neck, about the arm-pits, groins, or hams, daily bathing, and the occasional exposure of the parts to the air, together with sprinkling them with some unirritating absorbent powder, as tutty, levigated chalk or starch, is all that is usually necessary. Chaussier and Plenck caution us against the use of cerusse (carbonate of lead), as being sometimes productive of pains in the abdomen, paralysis of the hands, and all the other symptoms of lead cholic. Yet it is still not unfrequently employed in this country, and we are surprised to find it recommended by J. P. Frank, Mason Good, and Burns, as one of the best preparations for dusting excoriations in children. A lotion containing the sulphate of zinc, and a weak spirituous wash, are often useful applications.

The erythematous inflammation induced by pressure will generally cease on the removal of the cause. Where it occurs from lying long on the same parts, as often takes place in tedious fevers, in phthisis, and in those who are bedridden from other chronic disease, a change of posture, if possible, or the judicious application of pillows, so as to take the

weight of the body off the prominent and inflamed points, are obvious modes of relief. Protecting the skin by chamois leather, soapplaster, gold-beater's leaf, or white of egg coagulated by alcohol, are expedients to which we are obliged to have recourse when the posture cannot be changed. In low fevers the cutaneous vessels partake of the general debility of the system, and like other weak and irritable parts are readily excited to inflammatory action by the stimulus of pressure. Camphorated and spirituous washes seem, when early applied, to have considerable effect in hardening the skin, supporting the tone of its vessels, and enabling them to resist the influence of the above cause.

The treatment of the erythematous inflammation induced by extremes of temperature is to be found in all systematic surgical works.

The redness ensuing upon the sting of an insect is generally so transitory and trifling as not to require any medical aid. After the extraction of the sting, the application of olive oil with opium and ammonia are amongst the most effectual means of giving relief. The efficacy of ammonia is, probably, in some degree attributable to its chemical action, as the irritating fluid introduced by the sting is generally, as Tiedemann has observed, of an acid quality. A great share of its influence is also, no doubt, ascribable to its changing the mode of the sensibility in the irritated parts.

That species of erythematous efflorescence which is brought on by the application of chemical agents to the skin, usually ceases speedily after their application has been omitted; and its disappearance may be accelerated by emollients, fomentations, and other measures, which at once tend to remove all remains of the irritating substance, and to relax and soothe the excited skin. Where the irritating matter is of a resinous nature, oily applications will greatly facilitate its removal.

When the contact of urine and fæces is the source of the evil, frequent changes of linen are indispensable, and every effort should be made to keep the parts clean and dry. The detail of the expedients which have been devised for the fulfilment of this object is to be found in such works as treat of diseases and injuries of the bladder, urethra, &c.

When erythema results from the distention of the skin by tumours of rapid growth, relaxant applications under some circumstances, and the application of leeches and cold under others, are called for; but as such cases usually fall under the care of the surgeon, we shall not dwell on them here. Where this inflammation is induced by anasarcous distention, a horizontal posture is very important, and frequent fomentations, and keeping the limbs enveloped night and day in lint moistened with water, and the whole wrapped up in oiled silk, so as to prevent too rapid evaporation, are measures which tend notably to diminish tension by keeping the skin in a relaxed and perspirable state, and which have likewise great influence in subduing local inflammation.

When the

inflamed surface assumes somewhat of a livid or brownish hue, and threatens gangrene, the use of dilute spirituous and camphorated fomentations is the common practice, though the propriety of it is not universally acknowledged. Those who look upon inflammation as the source of all the danger, prefer soothing applications throughout. Whilst using these local measures, we must at the same time endeavour to promote the absorption of the effused fluid, support the strength, and combat disease of the heart, lungs, serous or mucous membranes, which so often co-exists in these cases, and as being the principal cause of all the other symptoms, demands our chief attention.

When the irritation of some papular, vesicular, or pustular disease seems to be the exciting cause of erythema, the latter may generally be disregarded, provided we take the proper steps for relieving the primary affection, and these will probably for the most part be found in the due employment of soothing or antiphlogistic measures. In that species which so often complicates acne, where it is constitutional, a cure need hardly ever be expected, as it seems to depend in some degree on a varicose state of the minute veins. Cold evaporating and slightly astringent lotions, with moderate but long continued pressure, are almost the only measures which afford permanent benefit in varicose affections of the smaller veins in other parts of the body; but they are, if not wholly inapplicable in this situation, at least too inconvenient to give them any chance of being steadily and long enough employed. Very great temperance, regular exercise, and avoidance of all those causes which we have pointed out as tending to exasperate this affection, should be strongly enjoined. Where the scurfiness is considerable, some mild ointment is useful in removing or concealing it. If the affection be purely local, slightly astringent lotions of lead or zinc, with a small portion of alcohol or vinegar, may be tried, or ointments of a similar nature; but they will too often prove nugatory in their effects. The popular use of watercresses and other raw vegetable matter, under the name of antiscorbutics, is highly irrational. A somewhat tonic regimen, and the use of flesh-meat in preference to an exclusively vegetable diet, are proper. We have lately met with a striking exemplification of this in the case of a distinguished artist, in whom this affection, induced by the habitual stooping which the exercise of his profession required, was greatly and suddenly aggravated by a strict adherence to a vegetable diet, and again diminished considerably on his returning to the free use of flesh-meat. The distention and acidity of stomach which an excess of vegetable food often induces, assist us in explaining its injurious effects in such cases. Where the eruption depends upon some chronic derangement of the digestive organs and an irritable state of the stomach, little can be expected from topical applications. Stimulants (and most of the empirical lotions for this

affection contain corrosive sublimate, and are of this nature,) are usually injurious, and to remove this efflorescence by astringents, where possible, might do much mischief, by exasperating the internal disorders from which they spring. Alkalies internally seem sometimes useful, which is attributable, probably, to their antacid power, and their directly soothing effects on the mucous membrane. The regula tion of the functions of the stomach, bowels, and liver, with a careful attention to the diet, are the most important points in endeavouring to prevent its increase.

The redness of the skin which is occasionally induced by inflamed ulcers, leech-bites, painful issues, &c., in addition to such internal antiphlogistic means as the existing state of the system may appear to indicate, requires locally merely the application of a bread-and-water poultice, or of lint, moistened with cold water and enveloped, as directed above, in oiled silk, to prevent its drying rapidly by evaporation. The erythematic inflammation succeeding to the use of leeches seems often to be induced, not so much by the irritation of the wounds they inflict, as by that excited in them by the subsequent application of Goulard and other astringent tonics. Where it is necessary to apply cold to a part immediately after leeches have fallen off, by confining ourselves simply to the use of cold water, in preference to these medicated lotions, we shall rarely have the mortification of seeing this cutaneous affection, which is often very annoying to the patient and his attendant, ensue; whilst, at the same time, the temperature may, by means of the coldness of the water and its gradual evaporation, be regulated quite as effectually.

Symptomatic erythema is associated with many inflammatory affections, especially those of the mucous membrane of the stomach and intestines; and the symptoms which have been by some attributed to the cutaneous affection are really, as well as itself, dependent on the state of the internal organs. The measly efflorescence so common in our continued fevers of some years, is a striking example of the sympathy of the cutaneous system with the mucous membrane. In dysentery, too, exanthematous efflorescences occasionally occur, and sometimes, according to Chomel, form a salutary crisis to the disease.

The erythema of Willan and Bateman, of which we have already given the definition, nearly coincides with Rayer's erythema symptomaticum, and has been divided into six varieties. In some of these the eruption is more or less elevated at some period of the course, thus slightly approximating them to the papular and tubercular classes; but these elevations are obscure and soon subside. Willan has, however, availed himself of their temporary existence to form the ground-work of some of his subdivisions.

1. Erythema fugax (maculæ volatica) consists of evanescent red patches of an irregular figure, which appear successively on the breast, neck, arms, and face in various febrile dis

orders, in bilious diarrhoea, in chronic affections of the primæ viæ, dyspepsia, hysteria, &c. The heat of the affected skin is increased, and the disappearance of the patches is not accompanied with any evident desquamation. 2. Erythema lave of Bateman coincides almost, if not altogether, with the species which we have already described as depending on dropsical distention. He dwells on the usual coexistence of anasarca, on the smooth shining surface, its appearance chiefly on the lower extremities, and its termination in desquamation, and says it may occur either in sedentary young persons, in whom exercise, diuretics, and corroborants will contribute to shorten its duration, or also in elderly or anasarcous subjects, especially if intemperate, and is liable to terminate in gangrenous ulcers. The distended skin is often chequered with patches of a dark red or purple hue. Horizontal posture, diuretics and bark, with weak spirituous lotions, are recommended by him. He adds, that it sometimes occurs without adema where the bowels have been much disordered, and occasionally is worse at the menstrual period.

3. Erythema marginatum occurs chiefly in old people on the loins and extremities in the form of patches, which are in some places obscurely papulated, and are bounded on one side by a hard, elevated, tortuous, red border, but are not regularly defined on their open side. They have an uncertain duration, and are not productive of any irritation in the skin. They are connected with some internal disorder, and are usually an unfavourable symptom.

4. Erythema papulatum consists of large, vivid, red, irregular patches, chiefly on the arms, neck, and breast, generally preceded for a day or two by obscure papula, which give a roughness to the skin. The eruption, after continuing about a fortnight, becomes bluish, especially in the centre of the patches, and gradually declines. There is occasionally, though not always, considerable constitutional disturbance, indicated by a small frequent pulse, anorexia, and great depression, with severe pain and tenderness of the limbs. The treatment consists in light diet, diaphoretics, the mineral acids, and attention to the state of the bowels.

5. Erythema tuberculatum occurs, like the preceding, in large irregular red patches, but through these small tumours are dispersed, subsiding in about a week, and leaving the erythema behind them, which, becoming livid, disappears in about a week more. It is usually ushered in by fever, and is accompanied with languor, irritability, and restlessness, and is succeeded by hectic. It is so rare, that Bateman himself never saw it, and Dr. Willan, on whose authority he gives it, met with but three cases, and medicine seemed to have no effect either in alleviating them or in warding off the subsequent hectic.

6. Erythema nodosùm seems peculiar to females, and occurs chiefly about the shins. It is preceded by slight febrile symptoms,

which cease on its appearance. It presents itself in the form of oval patches, with their long axis parallel to the shin bone. They rise slowly into hard and painful protuberances, which gradually subside within nine or ten days, their colour about the same time turning bluish. It is a mild affection, requiring usually only laxatives, mineral acids, and other tonics. We have known it, however, return frequently in the same individual, attended with considerable ædema, and after terminating in desquamation, succeeded by severe pains in the limbs, which demanded the employment of pediluvia, bandages, &c.

To these six varieties mentioned by Willan and Bateman, we give a seventh, general erythema, on the authority of Rayer, who says it has been overlooked by most writers on cutaneous diseases, or confounded by them with erysipelas. It consists in a superficial redness of the skin unequally distributed over various parts of the body, and occasionally differing but slightly from the natural colour of the integuments, and unaccompanied by swelling or vesications. It is attended with heat and dryness of the surface, and its duration rarely exceeds a week. The redness may be continued or intermittent, or appear only momentarily, during the exacerbation of gastro-enteritic or other acute internal inflammations. It often disappears on the approach of death. In those who recover, desquamation and falling out of the hair one or two weeks after the disappearance of the eruption, often occur.

This species, and, indeed, all cases where the erythema presents itself in an acute form, require antiphlogistic regimen, and occasionally venesection, with cooling and emollient lotions and the tepid bath.

In the chronic varieties of erythema, Rayer recommends leeches to be applied round the affected parts, together with tepid and vapour baths, or the douche impregnated with sulphuretted hydrogen. Where the cutaneous inflammation depends on some evident derangement in the stomach or intestines, the applicacation of leeches in the neighbourhood of these organs may also be necessary.

(W. B. Joy.)

EXANTHEMATA. - The word exanthemata, derived from the Greek term iariw, to effloresce, or break forth, was applied, by the Greek writers, to cutaneous eruptions generally. By modern authors its application is confined to cutaneous eruptions accompanied with fever, arising from specific contagion.

In the nosology of Cullen, the exanthemata constitute the third order of the class Pyrexia, and we find he has included ten different genera, viz. variola, varicella, rubeola, scarlatina, pestis, erysipelas, miliaria, urticaria, pemphigus, and aphtha. It is evident, however, he has included not only the eruptive fevers, strictly so called, but those diseases in which a vesicular efflorescence occasionally appears in their progress. Plenck, Frank, and others have fallen into a similar error. Willan and Bate

man classify the exanthemata according as the eruption agrees with their definition of an exanthema or rash, viz. "superficial red patches, variously figured and diffused irregularly over the body, leaving interstices of a natural colour, and terminating in desquamation of the cuticle." They therefore comprehend, under exanthemata, rubeola, scarlatina, urticaria, roseola, purpura, and erythema.

In the article FEVER will be found the classification of fevers we propose to adopt in this work, viz. into 1. continued; 2. periodic; and 3. eruptive. The eruptive fevers comprehend those diseases which we submit should alone be included in the exanthemata, viz. variola (and its modifications), rubeola, and scarlatina. In those diseases which bear a strong analogy to continued fever, we find that a certain order of febrile symptoms is followed by a particular eruption; that the fever and exantheme run a definite course; the efflorescence going through a regular series of changes, and terminating in desquamation of the cuticle; that these eruptive fevers occur only once during the life of the individual; and, lastly, that they are communicated by contagion.

The regularity of the eruptive fever and the progress of the efflorescence are most precise. The eruption of small-por appears on the third day from the commencement of the febrile indisposition, and maturates on the tenth; the rash of measles appears on the fourth, and declines on the seventh day; and the efflorescence of scarlatina is visible on the second day, and begins to disappear on the fifth; the progress of the fever being thus fixed and regular, and apparently keeping pace with the series of changes which the eruption successively undergoes.

The circumstance that eruptive fevers occur only once in the course of life, though correct as a general rule, is liable to occasional exceptions. These, however, are comparatively so few, that they tend much to confirm this principle. Persons on the other hand occasionally escape one or other of the eruptive fevers; more frequently, however, scarlatina than either small-pox or measles.

The last characteristic of the exanthematathat they are communicable by contagion-admits of positive proof as to small-pox, in the communication of this disease by inoculation.

Dr. Home succeeded in communicating measles by introducing the blood of a patient affected with the disease into the system of another individual; and the evidence of the contagious nature of scarlet fever is so strong, that no one in the present day ventures to impugn the doctrine. (See MEASLES, SCARLATINA, SMALL Pox, and VARICELLA.)

(A. Tweedie.)

EXPECTORANTS, (from ex and pectus; expectoro, expectorans, Expectorantia,) are medicines intended to promote the excretion of mucus and other substances from the

Clinical Experiments.

trachea, its branches, and the bronchial cells. In offering this definition, it is proper to mention that the existence of any substances capable of unloading the pulmonary tubes has been doubted; but experience has demonstrated that not only substances applied in the form of vapour or of gas to the parts now mentioned, promote expectoration, but that substances taken into the stomach produce the same effect.

The mucous membrane of the air-tubes of the lungs is the part intended to be influenced by expectorants. This membrane, which lines the whole of these tubes, from their origin, through their trunk, the trachea, and all its ramifications, to their termination in the bronchial cells, secretes a lubricating bland mucus, in appearance not unlike a thin solution of gum, intended to mitigate the action of the air on a highly irritable surface. When this mucus is accumulated, or becomes viscid and adheres to the sides of the bronchial tubes, or when it is inspissated or rendered acrid by inflammation excited in the membrane, so as to impede in any manner the function of respiration, then expectorants become useful by contributing to its removal. In effecting this, they operate in two distinct ways: 1. they either diminish the action which has produced the preternatural secretion, and thereby enable the natural effort of coughing to remove the morbid matter already existing in the air-tubes, or,2. they directly operate on the respiratory nerves, and powerfully excite those muscles the sudden simultaneous action of which is necessary for expelling the morbid matter. It is easy to conceive in what manner gaseous substances introduced into the lungs may promote this expectorant effort; but the question naturally suggests itself, do the substances taken into the stomach proceed to the lungs, and there exert their influence?

Many substances, when introduced into the system through the stomach, escape by the lungs. Thus, various odorous matters, oil of turpentine, ether, alcohol, phosphorus, and camphor, soon after they are taken into the stomach, become perceptible in the breath; and this is the case, also, when they are introduced into the system by other channels. M. Breschet and Dr. Edwards having injected oil of turpentine, in small quantity, into the crural vein of a dog, found that it was soon afterwards strongly exhaled from the lungs, although no odour of it was perceived on exposing the peritoneum.* From these and other facts it is evident that the lungs afford exit to substances which have entered the circulation: now, in admitting this, it is not unreasonable to suppose that some of the medicines administered with the intention of promoting expectoration also enter the circulation, and proceeding to the lungs, excite there the expectorant effort. But, although this conclusion be highly probable, yet it must be admitted that it is not susceptible of demonstration.

During this experiment, if a portion of the surface was denuded and a cupping-glass applied over it, the odour was not then perceptible in the breath.

All expectorant substances may be arranged under two heads.-1. those which effect the excretion by topical means; 2. those which effect it by general means.

1. Topical expectorants.-These may operate in two ways: a. they may directly stimulate the nerves regulating the action of the respiratory muscles, and, by exciting these to sudden action, may effect the excretion by coughing; or, b. they may compress the thoracic viscera by producing vomiting, and thus induce a sudden and forcible expiratory effort so as to effect the expulsion of matters from the lungs.

a. In explaining the manner in which the first kind of topical expectorants operate, it may be useful to consider briefly the nature of coughing. The act of coughing is a short and forcible expiratory effort, frequently repeated, the inspirations, in the intervals, being trifling in comparison with the expirations. Any irritation affecting the glottis, and acting upon a branch of that series of nerves which supply the respiratory muscles, excites involuntary coughing; but the action thus excited may be moderated, if it cannot be wholly checked and terminated, by the will of the individual. Coughing, whether voluntary or involuntary, is the result of the irritation of a certain set of nerves, and is intended to relieve the bronchial system of some offending cause; it is, therefore, a salutary phenomenon. In those debilitated by disease or other causes, the difficulty of exciting the act of coughing with force sufficient to produce the salutary effect, is so obvious as to strike the ordinary as well as the professional observer. The distress arising from this circumstance, the uneasiness caused by the irritating matters which coughing forcibly would readily remove, and the feeling of suffocation experienced from the accumulation of mucus obstructing the free passage of the air to the bronchial cells, are very considerable. In such states of the chest, the topical application of a stimulant to the bronchial nerves may so far rouse the exhausted excitability as to enable the muscles to perform the necessary effort; whilst, at the same time, the substances employed to produce this effect may be of a nature to prove also beneficial, by imparting a renewed healthy action to the diseased mucous membrane. The whole of the substances, arranged under this head, it must be recollected, stimulate so much as to require the utmost caution in their administration; but as the atmospherical air is the vehicle by which they are conveyed into the lungs, there is no difficulty in apportioning the degree of dilution so as to regulate the quantity of stimulus required or admissible.

The substances employed for the stimulating the mucous membrane of the bronchial system by direct application, and through it stimulating the respiratory organs, are few, and of these a small proportion only are in use.

Benzoic acid may be employed either in its separate pure form or at the instant of its

extrication from benzoin. In either case it requires to be largely diluted with atmospherical air, and combined with aqueous vapour. If the crystallized acid be employed, half a drachm should be put into an inhaler, and volatilized by the heat of a spirit-lamp; or, if the crude benzoin be preferred, half an ounce of it should be broken into small morsels and treated in the same manner. In the first instance, the diluted acid is the stimulating agent; in the second, the volatile oil, mixed with a small portion of the acid, rises with the aqueous vapour. Both are said to have proved beneficial in phthisis, even after the existence of suppurating tubercles had been clearly ascertained. The writer of this article has never employed these stimulants in phthisis; but he has seen much advantage derived from them in spasmodic asthma, in shortening the paroxysm and promoting expectoration.

Acetic acid acts nearly in the same manner as the benzoic. It is the oldest of the topical remedies of this order, is more manageable than the acid of benzoin, and does not require the aid of boiling water for its elevation. It is usually extricated from diluted vinegar; but as this contains sulphurous acid, distilled vinegar should be employed.

Chlorine is of very late introduction as a topical expectorant. It may be breathed by mixing it with the common air of the apartment of the patient, at the moment of its extrication from chloride of lime or of soda; or from a mixture of one part of peroxide of manganese and four parts of muriatic acid.* The former is to be preferred when a moderate stimulus only is required; but in general, for expectorant purposes, chlorine is obtained by expelling it from its saturated solution in water by the aid of gentle heat.

If an attempt be made to breathe chlorine in its undiluted state, it does not enter the lungs, but produces a powerful spasm of the glottis ; and, if this be not immediately relaxed, suffoca

tion ensues.

When it is diluted with a moderate portion of air, it excites violent coughing, irritation in the bronchial cells, great dyspnoea, and a painful, anxious sensation in the chest, which continues for several days. When largely diluted it operates as a salutary stimulus to the mucous membrane.

In its largely diluted state, chlorine gas was first proposed as a topical expectorant

In this process the muriatic acid, which is a compound of hydrogen and chlorine, is partially decomposed; and decomposition of the peroxide of manganese also takes place. The liberated hydrogen of the muriatic acid unites with one equivalent of the oxygen of the peroxide of manganese, and forms water; whilst the chlorine is set free in a gaseous state. This gas is of a greenish yellow colour, and has a pungent, acrid, suffocating odour. It is readily absorbed by water; but the solution, unless kept in a blackened bottle or a dark place, is changed in its character by slow decomposition of the water and the formation of chloric and muriatic acids. Its goodness is known by testing it with litmus paper: if good, it will destroy the colour of the paper; if it contain the above-mentioned acids, the paper will be reddened.