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.
I think it necessary before proceeding to the doctrine of the third chronic miasma, the most important of all, Psora, to premise the following general remark:
For the infection with the only three known chronic miasmatic diseases there is usually needed but one moment; but the development of this tinder of infection, so that it becomes a general disease of the entire organism, needs a longer time. Not until a certain number of days have elapsed, when the miasmatic disease has received its complete internal development in the whole man - not until then, from the fulness of internal suffering, the local symptom breaks forth, destined by a kind nature to take upon itself in a certain sense the internal disease, and in so far to divert it in a palliative manner and to soothe it, so that it may not be able to injure and endanger the vital economy too much. The local symptom has its place on the least dangerous part of the body, the external skin, and, indeed, on that part of the skin where, during the infection, the miasma had touched the nearest nerves.
This process of nature, which repeats itself continually and evermore in the same manner in chronic miasmata, - aye, even in those which are acute and constant, - ought not to have escaped the penetration of physicians, at least not in venereal diseases, to the treatment of which they have applied themselves now for more than three hundred years; and then they could not have avoided drawing a conclusion as to the process of nature in the other two chronic miasmata. It was, therefore, irrational and unpardonably thoughtless of them to suppose that every chancre evolved by the organism after several days, often after quite a number of days, as the result of the completed internal malady, was a thing merely adventitious from without and situated on the skin without any internal connection, so that it might be simply removed by cauterizing, "so as to prevent the poison from the chancre (scilicet) from being absorbed into the internal parts, and thus from causing man to be afflicted with the venereal disease." Irrational and unpardonably thoughtless was this false idea of the origin of the venereal chancre, which caused the injurious practice of the external cauterization of the chancre, producing as its unavoidable, shameful effect, the breaking out of the venereal disease from the internal which has continued in its diseased state. This has been the case in several hundred thousands of cases these last three centuries. Just as irrational and thoughtless is the notion of physicians of the old school, even of the most modern times, that itch is merely a disease of the skin, in which the internal portion of the body takes no part. According to this groundless supposition, therefore, nothing better can be done than to remove this ailment from the surface of the skin, although the extirpation of the internal Psora disease which causes the cutaneous eruption is necessary as an aid, and when this is cured also the cutaneous ailment, being the necessary consequence of the internal disease, will naturally disappear- cessante causa, cessat effectus.
For in its complete state, i. e., so long as the original eruption is still present on the skin so as to assuage the internal malady, the entire disease of the Psora may be cured most easily, quickly and surely.
But when by the destruction of this original cutaneous eruption, which acts vicariously for the internal malady, it has been robbed then the Psora is put in the unnatural position of dominating in a merely onesided manner the internal finer parts of the whole organism, and thus of being compelled to develop its secondary symptoms.
How important and necessary the cutaneous eruption is for the original Psora, and how carefully in the only thorough cure of itch, that is, the internal cure, every external removal of the eruption must be avoided, we may see from the fact that the most severe chronic ailments have followed as secondary symptoms of the internal Psora after the original itch-eruption has been driven out, and that when, in consequence of a great revolution in the organism, this itching eruption reappears on the skin, the secondary symptoms are so suddenly removed, that these grievous ailments, often of many years' standing, are wont to disappear, at least temporarily, as if by a miracle. See the before quoted observations of older physicians, Nos. 1, 3, 5, 6, 8, (9), 16, (17), (21), 23, 33, 35, 39, 41, 54, 58, 60, 72, 81, 87, 89, 94.
But let no one suppose that an internal Psora, which, after the external destruction of the original cutaneous eruption, has broken out into secondary 12 chronic ailments, can, through the reappearance of such an itch-like eruption on the skin, come into just as normal a state as before, or that it can be cured just as easily as if it were still the original eruption and as if this had not been as yet removed.
This is not at all the case. Even the eruption following immediately after the infection has no such unchanging constancy and pertinacity on the skin as the chancre and the figwarts show on the spots where they first appear,* but not infrequently disappears from the skin also from other causes+ than from artificial remedies used purposely for its destruction, and so also from other causes unknown. ++
So that the physician must not waste any time even in the original eruption, if he would complete the cure while the itch disease is still entire, by the use of internal anti-psoric remedies. Such a respite can be expected still less in this secondary eruption, which has been brought out on the skin by any cause after the local extirpation of the eruption; for the second eruption is wont to be far more inconstant and changeable, so that it often passes away on much slighter provocation in a few days - a proof that it lacks much of the complete quality of the primitive itch-eruption, so that the physician cannot count on it in the thorough cure of the Psora.
* Neither of these ever passes away of itself, unless destroyed externally on purpose, or the entire disease is healed internally.
+ E. g., through cold, see No. 67 of the above-named observations; through smallpox, No. 39; through warm baths, No. 35.
++ See Nos. 9, 17, 26 (36), 50, 58, 61, 64, 65, in which observations it may be seen at the same time that after such disappearances of the original itch eruption without appreciable cause just as many ill effects are wont to follow as when it has been driven away artificially through local applications.