in the dermoid tissue as those of the P. lupinosa; they are sometimes surrounded by thin, dry, furfuraceous scales.

The disease is attended with severe itching; upon the separation of the crusts, the parts beneath are found to be red and inflamed, smooth, polished, and often swollen. Here and there, small, depressed, whitish abscesses occur, from these there issues a small quantity of a viscous, colorless fluid, which thickens and dries, forming new crusts, analogous to those that preceded. Before the matter becomes perfectly dry, it exhales a nauseous smell, somewhat resembling rancid butter, or milk beginning to turn. (Plumbe.) This form of porrigo is confined to the scalp and parts immediately adjacent.

When porrigo furfurans occurs in children who possess but little irritability of skin, the disease is of a much more chronic character; there is also less disposition to pustulation, or to the exudation of fluid. A constantly repeated exfoliation of the epidermis, in the form of minute, dry scales, takes place; and the cuticular sheath which. envelops each hair for a short distance beyond its exit from the scalp, becomes more elongated, opaque, dry, and shining; giving to the hair, near its root, a shining silvery appearance, resembling the fibres of asbestos. (Teigne amiantacée of Alibert.) When the diseased hairs are cut off with the scissors, the skin appears furrowed, and somewhat red and inflamed. The itching is considerable. The diseased parts are usually destitute of moisture, hence no unpleasant smell is emitted. In severe or neglected cases, the lymphatic glands at the back of the head, and of the neck, sometimes become enlarged; occasionally the tongue has been seen studded with patches and vesicles. (Dendy.) When it spreads in the direction of the eyes, porrigo will occasionally produce severe ophthalmia. Tinea ciliaris will, in other cases, be produced, with an oedematous state of the puncta lachrymalia, and a discharge of the tears over the cheek; in very protracted cases, even ectropium, especially of the lower lid, may finally ensue.

Porrigo is capable of being propagated by inoculation or contact. It, however, frequently occurs spontaneously in children of unhealthy constitutions, fed upon coarse, fat food, crowded together in ill-ventilated apartments, and without proper attention being paid to preserve their heads and bodies, generally, perfectly clean. It is under these circumstances, and particularly when the disease, in its early stage, has been neglected, or improperly treated, that the most obstinate and aggravated cases occur. Porrigo is said to be of most frequent occurrence in low, marshy, and otherwise unhealthy situations. In the children of those in comfortable circumstances, to whose personal cleanliness daily attention is paid, the disease is generally produced by contagion, or results from a deranged state of the digestive, assimilating, and nutritive functions, the consequence of excess in the use of rich, fat, or oily food-in such children, the eruption is generally small in extent, and without much difficulty removed.

In proceeding to the treatment of porrigo, the condition of the patient's general health, and the state of the digestive organs particularly, should always be first attended to. Whatever indications of

internal derangement or disease exist, should be met by their appro priate remedies. The local treatment is to be restricted to frequent ablutions of the head with warm water, after the removal of the hair from and around the affected portions of the scalp, by a pair of sharp scissors; any loose hairs being detached by the forceps. This simple treatment will, in recent cases, and where the general health and that of the assimilating organs, is not extensively impaired, very often succeed in effecting a complete cure.

The entire removal from the scalp of the incrustations produced by the desiccation of the morbid discharges, and the matting of the hair should be early effected. It is all-essential to the complete and speedy eradication of the disease. Hence, when these have been allowed to accumulate, the head should be repeatedly washed with tepid water, and the diseased parts covered with a simple emollient poultice. If by these means we do not readily succeed in softening and detaching the crusts, alkaline washes should be employed, of greater or less strength, according to the greater or less thickness and firmness of the crusts. From one to two, three, or even four drachms of the subcarbonate of potassa, to the pint of water, may be used, according to circumstances. In detaching the crusts, no violence should be employed. The removal of the dead and loosened hairs is also a matter of some importance, and should not be neglected; the best plan is to pull them out by means of a small forceps.

We have seldom failed, in slight and recent cases of porrigo, after all local irritation has been removed by emollient washes and poultices, to effect a speedy cure by the application, night and morning, of the unguentum hydrargyri nitratis, or of an ointment of the iodide of potassium (one drachm to two ounces of lard), applied in the same manner. The parts should be well washed with tepid water in which a small portion of Castile soap has been dissolved, previous to the reapplication of either of the above ointments. In recent cases, touching the diseased parts with the nitrate of silver, will often cause an immediate arrest of the disease. The ointment of the ioduret of sulphur has been recommended by Biett and Schedel as a very effica cious local application for improving the condition of the scalp, preventing the formation of fresh pustules, and causing a healthy growth of hair. So long as any irritation of the scalp exists, all irritating applications, however, are injurious; the only proper remedies are then emollient poultices and washes of tepid warmth, and these should be immediately resorted to, should any degree of local irritation occur during the employment of either of the ointments or lotions recommended.

Care should be taken to prevent the contact of the diseased discharges from the scalp with the healthy skin; otherwise the disease may be extended and kept up for a considerable length of time.

During the treatment, the patient should be put on a diet composed principally of farinaceous substances; he should be afforded the benefit of a pure atmosphere, and have his bowels regulated by the occasional use of mild aperients; while the healthy action of the cutaneous capillaries is promoted and maintained by the daily use of the warm or

tepid bath, according as the heat of the surface is deficient or increased. In many cases, sulphurous baths, and gentle sulphurous douches every morning, will prove very useful adjuvants.

In chronic cases, a variety of lotions have been recommended; as solutions of the sulphate of copper or of zinc, of the deuto-chloruret of mercury, of the nitrate of silver, or of the sulphuric, nitric, or hydrochloric acids, more or less diluted. We are assured by Schedel that quickly washing the diseased portions of the scalp with diluted nitric or hydrochloric acid by means of a feather, and then pouring water on the parts, to prevent the action of the acid from penetrating too deeply, will very certainly cause the removal of the disease. By the same authority, touching the diseased parts with a small hair pencil, dipped in creasote, and subsequently applying an ointment of creasote (twenty grains to an ounce of lard), is asserted to have succeeded in the eradication of the malady, in cases where many other means had been ineffectually employed.

By Dr. A. L. Wigan, of London, a plan of treating the disease has been proposed, which is described as prompt in its effects, and uniformly successful. The whole of the scalp is, in the first place, to be carefully shaved twice, unless the quantity of hair is very small, and offers no obstacle to the complete examination of the skin. This is an all-important measure, inasmuch as when the scalp is covered with even a moderate quantity of hair, the disease may gradually spread beyond the parts originally affected, whilst the whole attention is paid to the latter. A narrow circlet of hair may be left around the face, as a concession to parental vanity, if there be no indications of the disease at this part, and it is carefully washed with hot vinegar.

The scalp being denuded of hair, Dr. Wigan directs it to be washed with the pyroligneous or concentrated acetic acid. In its first application he employs the acid diluted with three times its weight of water. This wash generally causes a number of red patches to appear upon portions of the scalp, which before its application looked perfectly healthy-showing that these parts had become infected, but without the disease having gone through its stages, which Dr. Wigan supposes, from a large number of observations, to require a space of eight days.

The whole extent of the disease being thus determined, with a piece of fine sponge tied to the end of a stick, or held in a pair of silver sugar tongs, each spot is thoroughly imbued with the concentrated acid, for the space of three or four minutes; when, according to Dr. Wigan, the disease will be fully arrested. He has often applied the acid a second time, but firmly believes that this is unnecessary whenever the scalp has been completely denuded of its hair, and the extent of the infection tested by the preliminary application of the diluted acid. With the growth of the hair, which soon sprouts again, if the eruption be recent, the crusts are gradually raised up. As soon as a pair of fine scissors can be inserted beneath them, they should be removed by clipping the hair; but we are warned not to do this prematurely, lest a sore place be produced.

We have seldom met with much trouble in curing cases of porrigi

nous disease of the scalp, excepting in constitutions of a very unhealthy character, particularly those strongly predisposed to scrofulous or tubercular disease. Our success we have mainly attributed to the attention we pay to the complete cleansing of the scalp, by repeated ablutions with warm water, and the occasional use of alkaline lotions; to the early removal of the hair by the scissors, and the removal of loosened and diseased hairs by the forceps; to the constant attention we direct to the condition of the digestive, assimilating, and nutritive processes, with the view of detecting and removing any derangement which may exist in either. This course, with perfect cleanliness of the patient's person and habiliments, free exposure to pure, fresh air, with a wellregulated diet, and appropriate exercise in the open air, has enabled us, in a very large number of cases, to succeed in the removal of the diseased condition of the scalp, with no further local application than emollient washes and poultices; or the application for one or two days of the citrine ointment, diluted or undiluted; or of the ointment of the iodide of potassium. The disease, however, is not one of very frequent occurrence in Philadelphia, at least in its more aggravated forms.

ERUPTIONS CONNECTED WITH LANGUID CUTANEOUS ACTION.

14.-Pityriasis.
Dandriff.

Morbid exfoliations of cuticle in different parts of the body, but in infants chiefly occurring on the hairy scalp, unaccompanied by much irritation or fluid secretion.

We are to recollect that in all infants, for some days after birth, an exfoliation of the cuticle takes place, as a natural healthy process. Dandriff, however, is the progressive desquamation of thin scales from the scalp, succeeding light, pink, unelevated patches; attended, in most cases, by a trifling degree of chronic inflammation of the vessels secreting the cuticle, but without the discharge of fluid.

This affection usually disappears in a few weeks if the infant in whom it occurs is not very much neglected in regard to cleanliness. But, under different circumstances, and particularly when, at the same time, there is a derangement of the alimentary canal, from improper or unwholesome food, pityriasis is now and then attended with considerable irritation of the scalp, followed by a fluid secretion and scabbing (P. scabida), or by a state resembling the porrigo furfurans. Under circumstances of peculiar aggravation, according to Plumbe, there is, in fact, no real difference between the two affections. In these severe cases, too, the hair often falls off; the eyelids, likewise, occasionally become diseased.

On the breasts of children, about the tenth year, there are often seen a few light, yellowish scales, scattered here and there, and sometimes so indistinct as scarcely to be perceived (P. versicolor). In this situation they sometimes resemble freckles, or light yellow stains; upon more minute examination, however, their squamous character

will be readily detected. In children of unhealthy constitutions, the spots will occasionally assume a dark, or livid hue (P. nigra, melasa); this will often be observed, more especially in children who have become debilitated by a residence in warm or tropical climates. When the dandriff occurs upon the scalp of infants, it is, no doubt, in very many instances, dependent on the disposition to determination to the head, so common at this age; it is not improbable, when attended by much irritation and fluid secretion, hyperemia of the cerebral vessels may even be prevented by it. (Plumbe.) The condition of the patient's health, therefore, requires to be closely considered, in deciding upon its treatment. Sedative applications are seldom advisable, or even safe; while those of an irritating character should never be employed.

Upon whatever part of the body the disease may present itself, it will demand little attention beyond what may be necessary to restore the patient's general health, and the regular action of the digestive functions, with strict attention to cleanliness of the surface generally. The exfoliation will usually be quickly checked, by simply washing with warm water. In more obstinate cases, a weak alkaline solution, as one drachm of the liq. potassæ to four ounces rose water, may be gently rubbed upon the part.

15. Ichthyosis.

Fish-skin Disease.

Ichthyosis consists in morbid thickening, with a dry and hard condition of the cuticle, evidently dependent upon chronic inflammation of the vessels by which the cuticle is produced.

It is unattended, at first, by any uneasy sensations, but, as the thickening of the cuticle increases, a sensation of increased heat, with redness, and other marks of more or less irritation are observed on the healthy skin, around the margin of the diseased part. When the thickening of the diseased cuticle causes it to rise above the surrounding surface, it begins to exhibit minute and innumerable fissures, which soon increase in length; and soon extensive cracks form, intersecting each other, and dividing the surface into innumerable fragments, of which each, considered separately, exhibits a great similarity, in structure, to the common wart. The diseased cuticle assumes a dusky, dark-brown color, which gradually approaches to blackness. This discoloration results from the entanglement of dirt by the rough and fissured surface of the skin, which even frequent ablutions will not prevent. On drawing the finger over the diseased surface, the sensation is the same as though the part was covered with large warts of long standing.

The arms and legs are the most common situations of this disease. It very rarely occurs upon the face.

The skin of infants in whom the disease is subsequently developed, instead of the usual smooth and soft texture, has, according to Rayer, a sallow, dry, shagreen-like appearance. The cuticle, during the first, or second month, becomes rough, and of a grayish hue, communicat