Otto Leeser described the Meaning of various terms he used in his homeopathic Materia Medica. Experimental therapy, Walbun’s Stimulation therapy, Humanization of materia medica etc….


Experiences on the actions of medicinal substances in disease lie scattered over centuries among all races. A collection of these empiricisms, even if it could be made, would still be unscientific. The last centuries of occidental culture have opened and prosecuted the question of the how of an event so penetratingly that our thinking is forcibly directed to the determination of the conditions under which the event occurs. Therefore the content of scientific thinking has become the experiment, that is, the observation of natural events under selected conditions. Materia medica should be or become scientific, that is, have or obtain an experimental basis.


The requirements of practical therapeutics, however, do not stand in any accord with the type and tempo of research progress. It is completely immaterial to the physician who technically intervenes into natural events, whether the use of the drug arises out of folk experience or is experimentally grounded. Indeed, the difficulty of experimentation in biologic fields, that is, the difficulty of avoiding false conclusions, always raises doubt in the mind of a physician on the accuracy of the experimental approach and makes him suspicious of laboratory science. But in reality it is only the pretension of biologic experimental science, arising out of excessive promises, which makes the great distance between practical demand and theoretic supply seem so insurmountable. In the leap into practice, most physicians leave the experimental science of materia medica of the University behind them.

Now the question is raised; Does this lie in the nature of the fact, is it true that experimental pharmacology and practical therapeutics approach each other with such difficulty or does it lie in the imperfection of the experimental method? And if it involves the last is this imperfection only temporally conditioned and is an improvement to be expected in the future with further development along present lines or is a re- arrangement of experimental work advisable? We should not forsake the basic orientation of contemporary science, the experimental method. We should not attempt to construe purely out of consideration of the nature of the medicinal substance, from its structure and its natural relationships. But we need to ask; is the plan of experimentation followed up to the present, the simplest, so to speak the economic way to the goal of practical therapeutics? We must affirm this question and indeed with good reasons. The relative clarity of drug investigation on the animal has so fascinated the laboratory investigator that he does not consider whether or not he treads on apparently uncertain grounds, as long as animal investigation seems to promise so many actual results. For a long time animal research was oriented purely toxicologically, that is, one investigated the disturbances on the threshold of ultimate damage to life. In so far as this study was preparatory for the clinic by a transference of results from animal to man one could not expect much more than a reversal, usually in the sense of a paralysis of single functions, moreover a palliative therapy (example: narcotics). Further, with the simple conditions of animal experimentation one could find additional explanations of previously known drug effects and here and there explain the limits of the field of application (example: cardiac drugs). The highly important results of experimental pharmacology on hormones, vitamins, etc. which have furnished a substitutive therapy, are omitted from the frame of this discussion. But the secret or outspoken claim of this animal experimental method has progressed far beyond these performances, to imply that out of the collected building stones the structure of an objective materia medica will be created in the future which needs only an objective application for the control of morbid processes in man. This claim was excessive: (1) because only a small part of human functions can be paralleled by those which can be represented in animal experimentation; namely, only those objectively recognizable alterations of living expressions mutual to animal and man. (2) The experimentally produced disturbances of normal animal functions do to permit a conclusion on the modification of an already disturbed (morbid) human function. (3) The supposition of constancy of the human organism, particularly the diseased organism, is a mental simplification which is entirely incompatible with actuality.


The therapeutic experiment on animals represents progress in animal experimental methods. By the incorporation of the therapeutic aspect into the study, the sources of failure in the transference to clinical trials are limited. In an animal made ill artificially (usually by bacterial infection), the healing effect of medicinal substances is studied and even attempts made to measure it. The original theoretic conception of therapia sterilisans magna of Ehrlich could not be maintained long, that is, the conception that bacteria in the body are directly killed by drugs whose type and amounts should not particularly affect the host. In the last decade careful study based on this working hypothesis has shown increasingly distinctly that such a viewpoint of only damaging drug effects is not tenable in a therapeutic plan under actual conditions. Generally it has been shown that damage to the infectious organism by the chemotherapeutic agent does not occur without the active participation of the host. The increase of the defense powers is shown to be just as important, if not more important, for the favorable effect of the chemotherapeutic agent as the disinfectant action.


Walbum’s metal salt therapy represents the most significant progress in this experimental therapy. Walbum’s laborious study has materialized thoughts with very noteworthy results, that is, to stimulate the defense of the organism of the host against artificial infections and indeed against artificially produced growths (tar carcinoma). Thereby Walbum obtained rules of dosage which are completely in harmony with those of homoeopathy, not only in respect to the minimal concentrations (up to the 23rd potency!) but also in the recognition of an optimal dose. This optimum is not only below the dose which is damaging to the bacteria and the host, but it must also remain below the Zone in which it stimulates bacterial growth. Here also the stimulative action on the two biologic units which stand in combat with each other represents the central point. It is obviously shown that the sensitivity of the host must be taken into account in the single phases. As an indicator in animals naturally only an objective sign, the temperature, can be used. Also the increased sensitivity of the diseased organism which stands in combat, in contradistinction to the normal organism, was demonstrated and observed. Just as homoeopathy so Walbum perceives in such stimulation therapy an alteration with a long after-effect.

The second problem which Walbum approached in his investigations was a qualitative one, specificity. His studies show particularly that in various infections as well as in tar carcinoma, by no means all the metal salts studied had a favorable effect, but at times only one or two; furthermore, various metals acted in different diseases. If one considers that the metals are catalysers for defense ferments or antibodies, this implies a variable suitability of single metals for diverse defense processes. This qualification, adaptability, balance, was ascertained by Walbum in a groping experimental way in that he tested, so to speak, all the possibilities. In such a procedure the difficulty is found in an almost unending task. For even if agents are found suitable for single artificial diseases of various animals, still this adaptability is shown only for these species of animals. Then begins the difficulty of transference of the results to the sick human. Furthermore, it is not easy to reproduce metal salt healing in animals themselves. For example, Walbum found that the nutriment of the animal was essential for the success or failure of the animal investigation. If fresh milk was added to the food of the mice infected with ratio bacilli, for example, the caesium treatment failed. If a great dependence upon other experimental conditions is shown in experimentally tested cases in animals, then it should not be astonishing that the metal salt stimulation therapy cannot be applied to sick mankind without further consideration, even if one observes all precautions in regard to optimal dosage. Actually the clinical application of this metal salt therapy up to the present has witnessed single encouraging results and frequent observations of failure. This is probably connected not only with the technical difficulties of optimal dosage but probably even more with the diverse other factors in the defense function in man, indeed, those which should be stimulated. Moreover, the significance of Walbum’s results above all leaves entirely untouched the possibility of transference to human-clinical relations. Their value lies more in that these therapeutic model investigations demonstrate the possibility and the principles of a stimulation therapy in animals through an ingenious arrangement. In regard to the dosage conclusions have results which are in full agreement with the medicinal stimulation therapy of homoeopathy.

While the qualitative specificity problem can be approached through groping animal experiment, a solution based on this procedure presents almost infinite difficulties. Even if one accepts as necessary the limitation of animal investigation to etiologically definite diseases with objective symptomatology (likewise separated from causes), then within this limitation a therapeutic animal investigation can be valued only as a schematic preliminary for clinical study; schematic because at best it can be considered as the general type of bacterial defense for the animal organism, but not the temporal and individually variable defense functions in man.


Here is the starting point of homoeopathy. With the postponement of the goal from the etiologic to the entire comprehensible symptomatology it steps beyond the naturally given limits of animal investigation. It considers the specificity problem directly in man. Through the introduction of a second equation it practically determines, so to speak, the X, the specific relation of drug to patient. It is a genial solution if one first answers by observations made on healthy man the question which of the defense functions is a single medical agent able to stimulate? The symptoms with which a man reacts to a drug make the qualitative specific connections available. So we have an equation of cure. The sick man indicates to us the nature of his defense functions in symptoms. In order to stimulate them we need only to compare the signs and to take them as indications. This leads to a solution which can satisfy us practically. Theoretically, we might solve the individual equations by themselves: that is, discover the defense functions in each case of disease in all details of how and by what and likewise the intermediate processes with which the healthy organism reacts to every medicinal substance. But practically we cannot expect the complete solution of this infinite task but we can use with advantage the available immediate observations as indications, as measuring sticks for determination of the suitability of the agent.


It is exactly the inevitable gaps of all animal experimental drug investigation which are filled in by the homoeopathic method. Further, it is an experimental and therefore fundamentally scientific method. For it places man in the center of natural interrogation from the start. Through the drug proving on healthy man it gains two heights; first, the avoidance of the sure of error of transference from animal to man and moreover the extremely important supplementation of investigative procedures by all the data which are obtainable only from man with the assistance of his capacity for communication, the so called subjective symptoms. The well-known source of error, the unreliability of these symptoms, is not able to neutralize this advantage nor to reject the method. The meaning of homoeopathic provings on men can be perceived in the humanization of the materia medica. The difficulties and limits of this attempt we shall consider further but the necessity of such a supplement of all materia medica will depend upon them. This theoretic advantage, moreover, becomes practical only through the therapeutic orientation of homoeopathy; it is primarily a stimulation therapy, it consciously utilizes the earliest, most active phenomena of the organism against a stimulus. And for this purpose the subtle, functional drug reactions, the individual indicative human reactions, serve far more than the signs of disturbance in any organism, animal or man succumbing or overcome and passively forced by a stimulus. We assume here certainly with right that the stimulus to an increase in performance is the high goal of therapy rather than the coercion which proceeds to functional incapacity.

Here a remark should be made whose basis will later become clearer. It is a mistake of the meaning of homoeopathy when Bier3 holds an acute mass investigation as narcosis with ether as an especially valuable drug proving in the sense of homoeopathy. The stormy course of depression of definite functions makes such an experiment hardly useful for supporting a stimulation therapy, regardless of whether it has been repeated a thousand times. Only the excitation of secretion of the upper air passages up to inflammation and the stage of intoxication are the paltry yield of active symptoms in this description, paltry because they are not sufficiently precisely described in their development and their characteristics and because the rapidly occurring paralytic symptoms are not described. Bronchitis and intoxication can be produced by many drugs. The homoeopathicity of ether to bronchitis is not to be doubted. But it is exactly here that the important individualizing characteristics for a differentiating therapy are lacking.

Briefly, the drug proving in man must be so arranged that the question What expressions of life is this medicinal substance able to excite or increase is answered with the uttermost exactness and differentiation, that is, which will respond as characteristic attributes to this one substance. It is exactly for this reason that homoeopathy has been occupied over a long period with continuous drug proving. What has been derived from it we shall examine more closely.


First, we must prove the therapeutic meaning of this humanized materia medica in another direction which is promoted in homoeopathy: that these medicinal effects on the healthy can be employed in the same sense to the patient. It is generally known that this transference occurs with the help of the simile rule, also through the comparison of the symptoms of the patient with the symptoms of the proven drug. Thereby nothing more is presumed than that: (1) the symptoms and signs afford the living defense of man against an injury (not once but throughout); (2) that the drug provings likewise furnish such defense symptoms; (3) by the concurrence of many symptomatic signs it is plausible that the defense functions in patients are involved and increased in the same way as they would be stimulated in the healthy. Thereby the increased sensitivity in the patient should find consideration in the dose. More than a great probability cannot be expected as in any biologic measure; also more is not aspired for in such balanced therapy, by the adaptation of the drug stimulus to the patient by symptomatic comparison. But to increase this probability evermore is to a high degree a matter of good drug proving, good art of observation on the patient and the ability to recognize the situation again.


The new meaning of homoeopathic materia medica brings with it a directness in the representation of drug action which, due to its simplicity, at first seems unscientific. But it is at least just as scientific to say at first what is, that is, to describe exactly, as to say, what one thinks about these manifestation at the time. Particularly when the simple factual description is neglected in comparison to mentally tracing back to common causes or by conception generalizations, there exists the great danger because at times modern theoretic conceptions must be completely given up in the use of drugs. But the causal or analytic way of investigation has become the flesh and blood of scientific investigators, so that the limits for recognition are stepped over by an excess of premature deductions, of very premature hypotheses, to the disadvantage of obtaining natural control. On the other hand I may remark here that the newest employment of scientific theory proceeds so that the goal of scientific perception is ultimately the revelation of what actually is and to see again in a type of description. I may mention here especially Rosenzweig and H. Herrigel. Indeed, it is not denied that the causal investigation in its place is also an important source of scientific recognition. It can be further developed within its limits for the control of natural processes. For the avoidance of disease, for example, this method of thinking may be regarded as sovereign. And exactly for the peculiar task of therapy, the influence of tendencies of the total organism or a part, this mental procedure proves fruitful. Scientifically the search down to the ultimate manifestations of the human organism and its exact description also is just as exact as the search for a causal explanation. In one by comparison to a therapeutic method, which homoeopathy is, the preference is given to the immediately observable and exactly described manifestation over all deductions on disease or organ conceptions but those given from the start. That the new orientation of thinking here conquers a practically new land I might consider a most significant point in regard to homoeopathy.

We are also convinced that it is entirely rational if the homoeopathic materia medica utters the speech of the sick patient as exactly as possible, that is, describes as exactly as possible by mimicking the patient. This is so much the better for the recognition of the symptom observed in the patient and finding the similar in the representation of the action of the drug. Further, one need not be frightened by the preponderance of merely orally reported, so called subjective symptoms. They are at once the most subtle symptoms and also the most subtle indications which can be evaluated.


What does one find in the homoeopathic materia medica? Arising out of drug provings on the healthy are apparently endless accounts of symptoms. The symptom register from the Hahnemannian circle of provers and the arrangement according to that pattern, increase the impression of incoherency in that the original proving protocols are no longer reported in their sequential development. Much more the single symptoms are to a certain extent taken out of their original connection as individual pictures and are arranged and related purely from an anatomical viewpoint. From these symptom registers it is usually not determinable from what prover a given symptom arose. Because one must not assume that the name attached (perhaps Hahnemann, Stapf, or Hartlaub) refers to an individual prover. Much more this name signifies only the reporter. This is evident without further discussion in that under the same name, symptoms from men and women appear. The designated reporters are therefore conductors of provings. This is important in respect to a noteworthy objection to all these old provings of Hahnemann in general. One asks himself: Can it be possible that this dozen zealous, self-sacrificing physicians, the first stimulated students of Hahnemann, have produced such an extent of symptoms and indeed by materials which frequently yield so slight an output of symptoms for us? For the appearance of the finest symptoms we must presume a type of hypersensitivity to the and first substance proven and it is exactly these hypersensitivities which we seek. Now should these few people be especially sensitive against all these materials? Naturally, this would be nonsense. Much more it follows that the number of provers, male and female, must have been much larger but that the symptoms were compiled subsequently and divided with rigid system. The highly desirable original crude material for our materia medica is no longer available in this form but in the absence of anything better we must thankfully accept it for the present. But we also have numerous drug provings in the original form of protocols. As especially good in German are those which arise from the Austrian circle of provers. But in the last analysis they too are not only aggregates but also frequently repetitions of symptoms. The register of symptoms as it arises from drug provings is not materia medica, but they offer the lasting basis, the lasting crude material, for the homoeopathic materia medica. To shape this from the crude material, to make it suitable for the student as well as the learned, is the difficult task which must be renewed by each generation with increasing knowledge. This task seems so difficult that, were we not profoundly convinced of the importance of such a humanization of materia medica, we would surrender our arms before the imperfection of present work. Also, all sifting, as perhaps in the materia medica of Dahlke, or all subdivisions of sifted symptoms according to guiding symptoms and organ symptoms like in the clinical materia medica of Stauffer, still the neophyte always stands before a chaos of symptoms into which at first he cannot bring any sense. If he relies purely on his memory, if he notes individually as many symptoms as possible, then in the determination of the drug he encounters the danger of mere mechanical covering of symptoms. As the thing lies in current homoeopathy, there remains nothing else for the student than to gradually derive from the various elaborations of materia medica, if possible also from English-American sources, rational pictures of drugs. It is rational to place the symptoms characteristic and differentiating for the drug in full light, in the foreground of consciousness and the less characteristic more and more in the shadows. Because if one has a patient before him, one should recognize the drug in the symptoms and the recognition is based in the general not on the many mental fragments lying beside each other in a mosaic, but on single out standing striking trends. As it is in the recognition of a person, so it should also be in the recognition of a disease and likewise a dug picture. For personal variations in this psychologic act there must naturally remain differences: the one is more inclined to conceive the constitution in toto, another is more adapted for the subtle details; one sees the total conformation of the pyknic type, the other a wart on the nose. But always belonging to the correct description and therefore to a good drug picture is the differentiation of essential and nonessential, of characteristic and frequent appearance.

Otto Leeser
Otto Leeser 1888 – 1964 MD, PHd was a German Jewish homeopath who had to leave Germany due to Nazi persecution during World War II, and he escaped to England via Holland.
Leeser, a Consultant Physician at the Stuttgart Homeopathic Hospital and a member of the German Central Society of Homeopathic Physicians, fled Germany in 1933 after being expelled by the German Medical Association. In England Otto Leeser joined the staff of the Royal London Homeopathic Hospital. He returned to Germany in the 1950s to run the Robert Bosch Homeopathic Hospital in Stuttgart, but died shortly after.
Otto Leeser wrote Textbook of Homeopathic Materia Medica, Leesers Lehrbuch der Homöopathie, Actionsand Medicinal use of Snake Venoms, Solanaceae, The Contribution of Homeopathy to the Development of Medicine, Homeopathy and chemotherapy, and many articles submitted to The British Homeopathic Journal,