"Now, it is not possible for a man to go on taking purgatives all his life through without undermining his health. Moreover, when the patches of psoriasis have disappeared, the patient no longer sees the necessity of persisting in the treatment. Hence, in all these cases there comes at last a time when the purgatives are discontinued, and then the eruption always sooner or later returns. It follows, therefore, that these remedies cannot effect a radical cure of the disease.

"Yet another method of treating psoriasis consists in the administration of diuretics, such as the salts of tartaric acid, squill, Herba Equiseti, Radix Bardanae, Baccae Juniperi, Ononis spinosa, Petroselinum Apium, Rhamnus cathartica, Folia Uvae Ursi, Digitalis, Aconite, Galium aparine, and the tincture of Cantharides. Of these substances, those first mentioned, which act mildly upon the kidneys, are altogether inert in cases of this disease; but the last of them must be admitted to be noxious, if not indeed to the psoriasis, at least to the patient affected with it. In every case in which I have prescribed the Tincture Lyttae (beginning, as is directed, with four drops, and increasing the dose to thirty drops daily), severe effects have been produced. As soon as the quantity given has amounted to fifteen drops, the patient has suffered from difficulty of micturition, and the urine has acquired a very dark color, containing albumen and afterward blood. In fact, the presence of these substances in the urine may be said to be a constant effect of this drug. Rayer, indeed, and the translator of his work into German, state that they have in several cases of psoriasis given the Tinctura Lyttae in doses of 50 drops, and once in the dose of 150 drops, with the result of curing the disease without injury to the patient. But if the reports of these cases be consulted, it will be found that the treatment included sulphur-baths; and, in my opinion, there is no difficulty in deciding whether it was the tincture of cantharides or these baths which contributed most largely to the removal of the psoriasis. At any rate, I have never succeeded in removing the eruption by means of this drag; whereas I have often seen it lead to albuminuria or haematuria, although I have given it with all caution and in comparatively small doses. But I have known many instances in which sulphur-baths alone, especially those made with the Calx sulphurata or Hepar sul-phuris calcareum (Kalksch wefelleber), have cured psoriasis, in so far as this disease can ever be said to be cured.

"Corosive sublimate, again, and the blue ointment have been recommended in the treatment of psoriasis by experienced observers; but I have repeatedly found them to be inert. In proof of this statement, I may refer especially to cases in which syphilitic eruptions have been combined with the affection in question; as, for instance, when a syphilitic ulceration (Helcosis syphilitica) has presented itself in a patient who had for years suffered from a non-syphilitic psoriasis. Under such circumstances, the former disease has been entirely removed by a mercurial treatment, while the latter has remained unaltered.

"Equally powerless against psoriasis are iodine and all its preparations. I have seen not a few cases in which other practitioners had continued to give iodine for years without the slightest benefit.

"Unfortunately, too, I must say the same of cod-liver oil administered internally. As is well known, this remedy has, by many medical men, and with great justice, been recommended in various cutaneous affections, particularly lupus. But in psoriasis it is altogether valueless.

"Arsenious acid, on the other hand, has been known, from remote times, to possess the power of modifying the horny tissues in man, as well as in the lower animals. Everybody is acquainted with the fact that it is given to horses with the object of making the coat sleek and glossy, and that it at the same time improves their nutrition and mettle, so that horse-dealers employ it to increase the beauty of these animals. Most probably it was this circumstance which suggested the idea of using arsenic in the treatment of cutaneous affections. Its efficacy in certain cases in which the epidermis is diseased is undeniable, so that it has been believed by some to be a proper and sure remedy in all the scaly forms of eruption. It has been extolled by writers of every country, and there are very few books or papers upon any chronic dermatosis in which arsenic is not mentioned in laudatory terms. This is, above all, the case in the works of Biett (edited by Cazenave and Schedel), Devergie, Hardy, Erasmus Wilson, Thomson, and Hunt. The last-mentioned writer, in fact, makes arsenic play so very important a part in the treatment of cutaneous affections, that 1 cannot but draw the attention of my readers to his statements - not, indeed, because I wish them to imitate his practice, but because I am anxious to show how dangerous it is, and to prevent his directions being followed by others who have not had so large an experience as myself in this department of medicine. I feel it to be all the more necessary for me to give this warning, because I know that some most distinguished and scientific men have been misled by Mr. Hunt's work, which is generally referred to upon the subject, and which in 18G0 was translated into German by Dr. E. R. Pfaff, of Plauen in Voigtland. Instead, however, of entering on a detailed criticism of this book, I will simply cite from it one passage to show the standpoint taken by the author. 'The disease,' he says on p. 16, 'will either get well spontaneously or not: if syphilitic, it must be treated accordingly; if otherwise, arsenic is the best alterative remedy.' I quote this as a specimen of the principles which guide Mr. Hunt, and of the summary method of procedure which he adopts in cases of cutaneous disease; but I must also mention that, besides giving the arsenic, he bleeds his patient several times usque ad deliquium, or has him cupped, and that he applies leeches to the red margins of those patches which have most recently made their appearance, and prescribes strong saline purgatives, or blue-pill, Hydr. c. Creta, colchicum, and colocynth. And yet he is obliged to confess that, in spite of this treatment, relapses took place repeatedly in the cases which he describes. This result is surely not such as to induce any one to adopt Mr. Hunt's method, or to coincide in the remark, quoted from an English journal in the preface to the German translation of his work, that 'Mr. Hunt has transferred these diseases from the incurable class to the curable.'