This section is from the book "The Chronic Diseases, Their Specific Nature And Their Homeopathic Treatment", by Samuel Hahnemann. Also available from Amazon: The chronic diseases, their specific nature and their homeopathic treatment.
This proneness to change in the itch-like eruption which has been called a second time to the skin, seems evidently to be caused by the fact that the internal Psora, after the destruction of the original itch-eruption, is unable to give to the secondary eruption the full qualities belonging to the primary eruption, and is already much more inclined to unfold itself in a variety of other chronic diseases; wherefore a thorough cure is now much more difficult, and is simply to be conducted as if directed against the internal Psora.
The cure is not, therefore, advanced by producing such a secondary eruption through internal remedies, as has sometimes been effectually attempted (see Nos. 3, 9, 59, 89); or by its re-appearance through other unknown causes (see Nos. 1, 5, 6, 8, 16, 23, 28, 29, 33, 35, 39, 41, 54, 58, 60, 72, 80, 81, 87, 89, 94), or, especially, through the help of a fever (see No. 64, also 55, 56, 74). Such a secondary eruption is always very transitory, and so unreliable and rare that we cannot build our hope of cure on it, nor expect from it the advancement of any thorough cure.
But even if, by any means, such a secondary eruption might, after a fashion, be produced, and even were it in our power to retain it on the skin for a longer period we cannot at all count on it for an assistance in the cure of the whole psoric malady.*
* There was a time when, not yet fully convinced of this fact, I thought that the cure of the entire Psora might be rendered easier by an artificial renewal of the cutaneous eruption effected through a sort of checking of the perspiratory function of the skin, so as to patient to sustain it for a time sufficient to produce an internal cure. When the plaster then was removed in order to relieve him, even the most violent itching, together with the eruption present, disappeared very soon, and the cure had not been essentially advanced by it; this confirms the observation made above, that the eruption, if evolved a second time (and so also the itching reproduced), had not by any means the full characteristics of the eruption of the itch which had originally been repressed, and was therefore of little assistance in the real advancement of a thorough cure of the Psora through internal remedies, while the little aid afforded loses all value owing to the often unbearable infliction of the artificially produced eruption and itching of the skin and the weakening of the whole body, which is inseparable from the titillating pain.
It remains, therefore, an established truth that the cure of the entire destructive Psora through antipsoric remedies is effected most easily only while the original eruption of itch is still present. From this it again appears how unconscionable it is of the allopathic physicians to destroy the primitive itch eruption through excite it homoeopathically to the reproduction of the eruption. For this purpose I found most serviceable the wearing of a plaster mostly on the back (but where practicable also on other portions of the skin); the plaster was prepared by gently heating six ounces of Burgundy pitch, into which, after removing it from the fire, an ounce of turpentine produced from the larch tree (called Venetian turpentine) was stirred until it was perfectly mixed. A portion of this was spread on a chamois skin (as being the softest) and laid on while still warm. Instead of this there might also be used so-called tree-wax (made of yellow wax and common turpentine), or also taffeta covered with elastic resin; showing that the itching eruption evolved is not due to any irritation caused by the substance applied, nor does the plaster first mentioned cause either eruption or itching on the skin of a person who is not psoric. I discovered that this method is the most effective to cause such an activity of the skin. Yet, despite all the patience of the sick persons (no matter how much they might internally be affected with the Psora), I never could evolve a complete eruption of itch, least of all one that would remain for a time on the skin. What could be effected was only that some itching pustules appeared, which soon vanished again when the plaster was left off. More frequently there ensued a moist soreness of the skin, or at best a more or less violent itching of the skin, which, in rare cases, extended also to the other parts not covered by the plaster. This, indeed, would cause for a time a striking alleviation of even the most severe chronic diseases flowing from a psoric source, e. g., suppuration of the lungs. But this much could not be attained on the skin of many patients (frequently all that could be attained was a moderate or small amount of itching), or, again, if I could produce a violent itching, this frequently became too unbearable for the local applications instead of completely eradicating this grave disease from the whole living organism by a cure from within, which at that stage is as yet very easy, and by thus choking off in advance all the wretched consequences that we must expect from this malady if uncured, i. e., all the secondary, chronic, nameless sufferings which follow it.
The excuse of the private physician (for the physician at the hospital has no excuse at all) amounts to nothing. He will say, indeed: "If it is not known- and hardly ever does it become demonstrably known- where, when, at what occasion and from what person avowedly suffering from itch the infection has been derived, then he could not discover from the present, and often insignificant little eruption whether it was real itch; so he was not to be blamed for the evil consequences, if he supposed it to be something else and endeavored to remove it from the skin as soon as possible by a lotion of lead solution, or an ointment of cadmia, or white precipitate of mercury, according to the wishes of the aristocratic parents."