There is, however, a species of baldness to which young children, as well as adults, are subject. This is styled appropriately alopecia circumscripta, or areata, circumscribed or areated baldness, because it occurs in spots. The patches of alopecia circumscripta differ from those of the present case in being completely destitute of hair, at least when the disease is thoroughly established and the case is a typical example. In circumscribed baldness the scalp is smooth, white and devoid of the nibbled aspect presented by the head of this little boy. In doubtful cases we can readily differentiate between the two affections by the test of microscopical examination, of which I will hereafter speak. We may decide, consequently, that this is not a case of alopecia circumscripta.

Seborrhoea sicca is a common disease of the scalp, which may occur even in children, though, as a rule, it does not develop as early as the ninth year. Seborrhoea is accompanied by scales, but they are larger than those of the present case and have a greasy appearance. Seborrhoea eventually causes fall of the hair, but it does not produce splitting and breaking of the shaft, and, therefore, is never attended by that nibbled, moth-eaten aspect which is displayed so conspicuously in this child's case. The scalp is one of the favorite regions of psoriasis. That disease is prolific of scales, but they are firmer and thicker than we see here, and the history of a case of psoriasis is widely different from that furnished by the father of this little patient. Psoriasis does not spare children, but it begins with one or a number of papules which slowly enlarge and coalesce to form areas, often of considerable size. It is not usually limited exclusively to the scalp. Moreover, in psoriasis we never behold nibbled hairs. Squamous eczema of the scalp is, indeed, accompanied by scales, but the scalp is red in eczema and the hairs are intact.

There is one circumstance in the history of this child which is very significant.

| Whenever you are told that a disease of this character is supposed to have been acquired at school you are warranted in suspecting a parasitic origin. Wherever possible push your inquiries in order to ascertain whether similar cases have occurred among the child's schoolfellows or playmates. It is not possible to obtain assurance on this point in the present case. The father has no knowledge upon the subject. He does have, however, some general knowledge and suspicion of the nature of the trouble. He thinks "it looks like ringworm." That is it, gentlemen. The father has pronounced the word. It is a case of ringworm of the scalp, known to physicians as tinea tonsurans or herpes tonsurans. The latter term should be rendered obsolete. It is an old designation which has been handed down to us and which is a misnomer, because tinea tonsurans has nothing to do with any form of herpes. Tinea is a parasitic disease. Now you know that in the realm of skin diseases we have to deal with some which are due to animal and others which are caused by vegetable parasites. Tinea tonsurans is an affection of the latter variety. The title tinea is derived from a Greek word signifying moth, and it is no inapt descriptive term for a disease which occasions what we may call a moth-eaten appearance of the scalp. Tinea depends upon the growth of a microscopic fungus known as the tricophyton, i.e., hair-plant. If you examine under the microscope a diseased hair or a scraping from the scalp of the affected region you will see the fungus with its spores and mycelium, the former being small, round, refractive bodies, and the latter consisting of long, slender threads which spread in different directions and frequently interlace. This fungus does not limit its ravages to the scalp, but also attacks the bearded part of the face and the body in general. Tinea tricophytina is, accordingly, the name of a group or class. When the parasite affects the beard the discase is styled tinea sycosis or tinea barbæ

is termed tinea circinata or tinea trichophytina corporis, ringworm of the body. In other words, whether the fungus locates itself upon the scalp, the beard or the body at large, the disease is essentially the same and is treated in essentially the same man

ner.

A totally different disease excited by a vegetable parasite is called favus or tinea favosa. Favus is much less common than ringworm and is quite dissimilar in appearance. Favus manifests itself in the form of small, round, or oval, cup-shaped crusts of a sulphur-yellow color. Favus is also characterized by a peculiar and distinctive "mouselike" odor, due to changes in the skin and hardened pus. The color of the scalp in ringworm is sometimes pale red and in other cases of a grayish hue. In weak or scrofulous children it may occasion suppuration and the formation of thick crusts. Tinea tonsurans causes violent itching, but no pain. The fungus penetrates the substance of the hair and renders it brittle. In extremely severe cases, known as tinea kerion, or kerion Celsi, all the layers of the skin and the subcutaneous tissue in addition are involved, the parts are swollen and painful and the inflammation may destroy the hair-follicles and result in permanent baldness. As a rule, the hair is reproduced after an attack of ringworm has been cured. Tinea tonsurans is a contagious affection. In whatever manner the trichophyton fungus gains access to animal tissues the result is the same. The domestic animals are very prone to its attacks. Dogs, cats, and horses are often affected. From these it may very readily be transferred to the children of a family. "Mangy dogs" are the subject of ringworm. When one child has acquired the disease it is generally communicated to his companions. Weak, scrofulous, and anæmic children are particularly susceptible to the contagion.

Tinea tonsurans, when it obtains entrance to orphan asylums, will often attack most of

frequently proves very hard indeed to eradicate. I was on one occasion called in consultation to a "Home," and found that the disease had been present for three years. In such cases there is one measure which should precede every other plan of treatment, and it can be told in one word, viz., isolation. Affected children must be segregated from their fellows. Special nurses and attendants must be set apart for the purpose of taking care of those who have ringworm, and to limit the extension of the disease. It is only by the use of such precaution that we shall be able to stamp out an epidemic. Isolation is of more value than a mere reliance on parasiticides.

Years ago it was customary among mothers and nurses to wash the head with water when ringworm was present. This, however, is a bad practice, which I mention only to condemn. For the trichophyton fungus thrives upon water and, therefore, that fluid should not be used unless it is impregnated with an antiseptic and parasiticidal agent. One of the best of these is a saturated solution of boric acid. Four drachms of boric acid to five ounces of water is an effective application. In private practice we may advantageously employ equal parts of alcohol and water instead of plain water. Or the acid may be dissolved in olive-oil in the proportion of a drachm of the former to an ounce of the latter. In the same proportion we may prefer to make use of an ointment of boric acid prepared with some fatty base. An ointment containing from 10 to 30 grains of copper oleate to the ounce is also a valuable application. Another efficient remedy is ointment of the nitrate of mercury, alone or combined with resorcin. Half a drachm of resorcin to half an ounce of the ointment named is an excellent combination.

As regards the practice of epilation, authors differ much. Some are greatly in favor of the method, while others oppose it with equal confidence. I range myself in

In addition to the agents which I have mentioned there are many others employed for their parasiticidal effects. Turpentine, sulphur, chrysarobin, carbolic acid, salicylic acid, and many other substances have been used with more or less success.

Internal medication has no direct influence upon the disease, but in the case of pale and weak children tonic remedies are advisable on general principles. For the boy before us I shall order syrup of the iodide of iron to be given thrice daily in the dose of 20, increasing to 30 minims.

CASE II. PSORIASIS.

Our second patient is a man, 58 years of age, who has an eruption scattered over the greater part of his body. The disease has been in existence for about two years. It itches violently and he can scarcely sleep at night. The lesions first appeared in front of and just below the knees and spread thence to other regions. The earliest objective manifestation occurs in the form of small papules covered with white and dry scales. Some of these primary lesions are present upon the body to-day, and the patient points them out to me, as he has by experience become thoroughly familiar with their appearance. If the scales be removed from one of these papules a bleeding point will be exposed. In course of time the individual papules enlarge, and those which are situated near each other often coalesce, and in this manner are formed the large patches which are so numerous upon the person of the patient. The intervening skin between the papules or the patches is perfectly healthy. There is no gradual

In various places you can see semicircular or irregularly serpentine outlines of eruption. You heard me, in speaking of our first case, state that the circular or semicircular outline is so characteristic of ringworm as to give that disease its popular name. I also alluded to the existence of scales in ringworm of any form. These statements are very analogous. Have we here, then, another case of ringworm? Not so, for although the words are alike the appearances are different. The scales of tinea are fine, branny, or furfuraceous, to use a technical expression. The scales of the case now in your presence are, on the contrary, thick, firm, white or silvery in aspect. Each scale is of considerable size and consistence. The annular outline of the lesions is so constant in tinea as to be characteristic, but, nevertheless, it is by no means confined to ringworm. Consider for a moment how the annular form is produced. The eruption does not immediately outline a circular figure. No; it develops uniformly in a round or oval patch, but when it has attained a certain dimension the border remains intact or may even continue to spread while the centre fades and returns to or toward the normal. This process leaves an annular lesion. Something analogous to this occurs in several altogether distinct diseases of the skin. The border may partially fade, and then if neighboring semicircles impinge upon each other a variety of gyrate, serpentine, grotesque figures may result.

You perceive that this man has a wellbuilt frame; that he is hale and vigorous; that he makes no complaint of diminished energy, but comes here, in the first place, to be relieved of the abominable itching, and, secondly, to have his skin cleared of the unsightly and scaling patches. A minor trouble of such a case, though it is distasteful to persons of neat habits, is the constant accumulation of scales in the clothing.

From the foregoing facts, coupled with