These cases (a, b, and c) refer to convalescent patients, of nearly the same age, viz., 10 years each; their respective heights being 46, 48, and 481⁄2 inches; and their weights, 48, 50, and 49 lbs. Although confined to the wards of the Hospital for Sick Children, under my friend Mr. Holmes, they were at the time of examination in good health, while the care employed in collecting the urine was such as to leave nothing wanting in this respect. The diet was "meat" and cocoa; no medicines were given.

The chief noticeable point in the icthyosis example, after allowing for a proportional difference in age, weight, and height, is the large increase in the actual bulk of urine, being considerably more than twice as much as that passed by (a) and (b), and nearly double that of (c). The specific gravity, determined on each occasion by weight, is also, in a corresponding manner, low. Notwithstanding the small rate per cent. of urea, the absolute amount in 24 hours is little altered in icthyosis; and this is somewhat remarkable, when we consider that the skin, as a secreting organ, is reduced to the lowest possible limits, in the disease. This fact militates against the usually received theory of the elimination by the skin of urea. In determining the latter substance, as well as the phosphoric acid, I have adopted the volumetrical method, where 1 cc.01 of urea, and a similar equation applies to POs. The sulphuric acid has been obtained in every case by the more tedious but safer process of precipitating by baryta, and finally by weight: it is hardly if at all affected, or phosphoric acid, by icthyosis. No hippuric acid crystals were detected by examination with the microscope.*

Schlosberger is said to have demonstrated the presence of hippuric acid in the scales of icthyosis (Neubauer on the Urine, p. 34). None, however, could be discovered in the above case of icthyosis after a most careful analysis by Dr. Marcet.

F

Prognosis.

of icthyosis.

The prognosis of icthyosis, in its several varieties, is unfavourable as regards complete relief; but the complaint is one which is nevertheless greatly amenable to treatment. After a time the skin becomes clear, the scales are no longer renewed-a source of no slight satisfaction to the patient. The original malformation, however, in any case remains, and with it a tendency to the return of the disease, which may be invoked by many causes, such as exposure to atmospheric changes, or the neglect of precautionary measures; and it is to the nonfulfilment of the required conditions, in so far as they relate to the general health and the state of the skin, that a relapse is in most instances attributable. No benefit can accrue from the internal exhibition of mercury, and arsenic will seldom be needed. The local Treatment treatment should be conducted on the principle of compensating in some way for that deficiency in the secreting power of the skin, which is so signally shown in icthyosis. For this object, glycerine, as a bath, is very serviceable; it removes the dryness of the skin, and renders it soft and supple. Formerly regarded as a waste product, and hence obtained at an almost nominal sum, it has now become a therapeutical agent of acknowledged efficacy in the treatment of all squamous affections. Its introduction we owe to Mr. Startin, who recognised its value as long ago as 1844, and since that period it has more than quadrupled in cost. When, however, from its high price, a sufficient quantity for a bath is not procurable, it will be enough for the patient, after taking an ordinary warm bath, to sponge the whole surface with from one to two quarts of tepid water, containing two or three ounces of glycerine; or take a warm bath, prepared in the usual mode, with a pound or more of linseed,

made into a mucilage by boiling, and mixed with it; or an alkaline bath, of sufficient heat to be agreeable, in which the patient may remain for twenty minutes or half-an-hour, and when quitting it, while the body is still wet, a few drachms of pure glycerine should be well rubbed into the skin before drying with a towel; used in this manner, glycerine loses much of its greasy quality, and the skin is left pliable for some hours. Before retiring to bed, the patient should be advised to apply an ointment, similar to that named in a preceding page, and consisting chiefly of camphor. During the day a lotion of borax will prove of benefit; or one of dilute nitric acid, in the proportion of half a drachm to seven ounces of water, with half an ounce of glycerine; or we may use one of dilute acetic acid. The general health should be supported by tonics, especially those of the ferruginous kind; and if the complaint is unusually obstinate, small doses of arsenic may be afterwards added; above all is required a sufficient quantity of animal food daily. The internal administration of pitch is highly extolled by Elliotson, but in other hands it has wholly failed. As an ointment, Neligan makes favourable mention of the iodide of potassium-a drachm to an ounce of lard, which he directs to be well rubbed into the affected surface morning and evening.

Among the complications of congenital pityriasis and icthyosis, none are more common than eczema, and particularly in early life. At a later period, I have sometimes seen it co-existing with rupia.

cornea.

There is yet another variety of icthyosis, as intractable Icthyosis as it is infrequent, which remains for descriptionicthyosis cornea. As a general disease I have never it. The following is an abridged account,

seen

derived from Mr. Startin's Lectures :-The complaint in question is characterised by a hard and horny state of the integument, emanating at first from a single spot, and at last invading the entire frame. Little change may be perceptible to the eye, but a feeling of preternatural rigidity is experienced by the hand on touching the surface; the rigidity has its seat in the subcutaneous tissue rather than in the skin itself. The course of this affection is rapid from bad to worse. The limbs become contracted, and the trunk encased in a horny covering, rendering any attempt at motion impossible. In the case recorded by Mr. Startin, which is also that to which Alibert refers, its hereditary nature was unproved. As an example of its partial occurrence I may narrate the following:-T. B., aged 26 years, by trade a smith, and exposed to much heat, came to the Skin Hospital an outpatient, May 26th, 1862. On the palmar aspect of both hands, including the fingers, were a great number of hard, dense, horny, and parallel ridges, like so many severe corns. Others of a like kind were conspicuous on the dorsal surface of the feet, and above the heels. They had existed as long as the patient could remember, and he dreaded, from the subsequent pain, to put his hands into warm water. The complaint was clearly hereditary; his mother, and also a sister and brother, having been severally attacked, but not to the same degree. In such an extreme case it was impossible to afford him much relief, so long as he continued his employment; and I only allude to it, as one of those rare instances of the disease, which concludes the list of the squamous class.

1

CHAPTER V.

LICHEN.

characters.

THE distinctive characters of the papular eruptions, first General recognised and classified by Willan, have been acknowledged by most subsequent writers on diseases of the skin. They comprise lichen and prurigo; and include, under the former, strophulus or gum-rash.

As a rule, the papular eruptions are characterised by pruritus, and by an elevated state of the papules of the skin, which undergo no further change. They are devoid of any kind of moisture, and in no way contagious.

Several varieties are assigned to lichen, which, as an Varieties. ordinary eruption, is met with in a simple or in a chronic state; the terms lichen simplex and lichen agrius being employed respectively to designate these two classes. The other, but less common, forms of lichen, as lichen tropicus, lichen urticatus, lichen circumscriptus, lichen pilaris, and lichen lividus, may be said to depend rather for their nomenclature upon some such causes as situation, colour, or climate. Two kinds described by Hebra remain to be mentioned, lichen scrofulosus and lichen ruber.

Lichen is generally characterised by successive deve- Course. lopments of fresh papules, although Duparc and Alibert relate instances of the eruption being simultaneous and complete. It spreads gradually, but not often by con