physical and chemical laws have doubtless an influence, but are subject to the laws of organic irritation and are essentially modified thereby. A close comparison of recorded pathogeneses has shown that all bodies, whose constituents have been singly subjected to a pathogenetic proving, do not lose all their individual peculiarity when chemically combined in favour of this new combination, on which account my colleague and friend Dr. Beck, the initiator of the cure of diphtheria, to whom we are indebted for this knowledge, has differentiated the action into ideodynamic and metadynamic. To the latter belong, for example, the weak non-basic acids which do not essentially alter the pathogenetic character of the basic body combined with them to form a salt, such as Carbonic acid in its combination with Oxide of Iron; on the other hand where this is combined with Hydrochloric acid, this impresses on it its peculiar pathogenetic stamp and thus displays its isodynamic power. Now if the chemical character of the Mercury as well as of the Hydrocyanic acid is distinguished by a marked substantiality, this will be still more apparent in their respective pathogeneses. But yet, without the help of the methodical physiological provings made by Hahnemann and his disciples on the relatively healthy human organism, the usus in morbo and the observation of cases of accidental poisoning, have revealed specific positive actions of both these substances which are the common property of all medical schools, from which, guided by the law of similarity, the therapeutic applicability of their chemical combination to the curative treatment of diphtheria might have been referred a priori. Thus no one doubts the local specific relation of Mercury (in most of its preparations) to the mucous membrane of the mouth and fauces together with the adjacent salivary and lymphatic glands, nor the character of central paralysis which is proper to the pathogenetic individuality of Hydrocyanic acid, by which both these substances when chemically combined assert their isodynamic power. Who can fail to see the specific concordance of these two pathogenetic characters of action conjoined into one in the Cyanuret of Mercury, with the

diphtheric morbid process, in which two pathogenetic elements occur in combination; a vegetative attacking the mucous membrane and glands, and a neuroparalytic to which the fatality of the morbid process is owing?

Five identical and simultaneous observations will suffice to show the homoeopathic therapeutic relation of Cyanuret of Mercury to diphtheria. The former stands to the latter as the absolute cause to the inevitable effect.

This relation, which I hope I have clearly proved, postulates the necessity of minimal doses. In proof of this I would refer the reader to the comparison of the results obtained by myself and those obtained by others who have employed more massive doses of the medicine in question. I would intreat all those who are inclined to make a trial of the treatment to use only my diluted doses. If more massive doses of Cyanuret of Mercury should come into general use, as seems to be the tendency if I may judge by the cases published in our periodicals, it is to be feared that a remedy which has succeeded in innumerable cases may be discredited and fall into disuse.

If I have failed to show convincing scientific reasons for the treatment I recommend, yet the success obtained by it renders it worth trying. This reminds me of what Hahnemann said to the medical world when he published an account of his method:- "I do not ask you to believe me, repeat what I have done, but repeat it exactly."

I have now to speak of "experimental investigations" which I made on the diphtheric patients treated by menot, as some might suppose, to their disadvantage.

The following circumstances led me to make them :Some physicians who have given in their adhesion to the Hahnemannian doctrines and have adopted them in their practice, have not advanced beyond the idea of the positive action of medicines, and hence prefer almost exclusively the lower degrees of the Hahnemannic rule of rarefaction, to the higher and highest potencies, whilst others after having at first considered themselves bound to follow the posological directions of the master, have afterwards confined themselves to empirical facts that were in favour of the supe

riority of extremely attenuated medicinal doses. I have not considered it right to keep aloof from the disputes raised on this subject. After having employed the theoretical weapons, briefly set forth above, with but little success, I set about collecting statistics relating to the treatment of diphtheria, whereby the controversy might be settled. When I had observed a sufficient number of cases to assure me of the specific character of the Cyanuret of Mercury, I abandoned the dose I had hitherto used and gradually went beyond the sixth dilution. In this manner I got up to the thirtieth dilution and remained there, having only gone beyond it on one occasion. The result of my investigations was to convince me that the higher the dilution the more precise was the curative, or, as I have termed it, the negative action of the medicine. Since I have adopted exclusively the thirtieth dilution, I have observed that the diphtheric exudation disappears in a somewhat shorter time than with the sixth or twelfth; but, on the other hand, the appearance of the patient ten or twelve hours after taking the first dose of the higher dilution is unmistakably improved. The stage of convalescence, too, is diminished to the shortest, but even were there not the slightest difference observable in the effects of the sixth and thirtieth dilutions, the latter is to be preferred, because if the smaller quantity suffices, it is not advisable to employ a superfluity.

The advantage of the microdosal treatment of diphtheria by Cyanuret of Mercury may be summed up as follows:

1. The commencing involution of the fully developed morbid process usually shows itself twelve hours after the first dose by a diminished extension of the exudation, the decline of the subjective symptoms of deglutition and of the headache, increased strength and diminished frequency of the pulse, increased urinary secretion, sleep, appetite, cleaning of the tongue, normal stools, equal distribution of moderate cutaneous temperature and slight action of the skin, and the physician can see the improvement in the altered expression of his patient as soon as he enters the Betwixt the evening and the morning a serious

room.

disease has changed into a trivial ailment which scarcely requires any further medicinal treatment.

2. In order to get rid of all objective and subjective symptoms a period of twice, seldom thrice, twenty-four hours is required.

3. The stadium convalescentia is quite insignificant in length.

4. The occurrence of consecutive diseases, even those of of a paretic character, is avoided.

At the commencement of the treatment I give the appropriate dose every two hours; after involution has set in, every four hours; when the recovery is assured, thrice or even twice a day. But from one observation where the patient only took one dose of Cyanuret of Mercury 30 before my second visit, whereupon the involution set in just as well as when the medicine had been taken every two hours, I imagine that I may have been in the habit of giving the medicine with unnecessary frequency. This would justify the recommendation of Hahnemann not to repeat the dose as long as the curative action of the first dose is going on. To determine this point experimentally, however, demands the continuous observation of concrete cases, which can scarcely be done in private practice; for this the practice of a public hospital would be required.

For prophylactic purposes I consider it sufficient to give a daily dose of the 30th dilution of Cyanuret of Mercury as long as danger of infection exists. By this means I have succeeded in limiting the disease to the one case to which I was called in, in poverty-stricken, unhealthy abodes abounding in children, among whom all sorts of constitutional maladies were rife. But private practice is insufficient to provide the material for a decisive experiment. Thus it was only by Dietl's extensive experiment in the Vienna Hospital that Hahnemann's verdict against bloodletting in inflammatory disease could be statistically confirmed.

The conclusion leads me back to the subject mentioned at the beginning of this essay.

By the "practical deductions" demanded by the terms

of the prize thesis I understood those relating to therapeutics (and prophylaxis) whereby populations threatened by the dreaded calamity may be protected. An extensive and profound knowledge of the disease is indispensable, and we and posterity are greatly indebted to the investigators who have helped us to this, but I think I have shown that experimental investigation of the positive effects of medicine is equally if not more necessary, and this necessity has been pretty generally acknowledged in recent times, and has led to a revolutionary reform of the materia medica, which has engaged the services of a large number of investigators. The historical part of this essay shows that we have succeeded in combating and rendering innocuous the diphtheric morbid process, although we were not provided with any pathological knowledge of its nature. If our knowledge of the remedy was at the same time one-sided and incomplete, it was sufficient for the concrete case that presented itself. The fact of a cure by art of diphtheria had long been familiar to us when we were made acquainted with microbes in general and with the micrococcus diphthericus in particular, as the cause of the disease. This circumstance throws a strong light on those sources of help to which therapeutics must have recourse in order to arrive at the desired practical results. I must here recall attention to the doctrine belonging to pathology above mentioned, which treats of occasional and constitutional causes of diseases. When the indication is drawn from the knowledge of the parasitical micro-organism that the local destruction of the latter should be undertaken, the treatment based on this is directed solely to the occasional cause of diphtheria, which on account of its ubiquity withdraws itself from medical skill, and in doing so leaves the constitutional morbific cause entirely out of sight, but it is just this last against which the special treatment is directed, for it substitutes for the disease to be cured the absolute cause of the latter which is completely under the control of the physician, so that the medicinal dose may be regulated with accuracy by means of a simple technical process. The successful performance of prophylaxis rests on the