The symptoms which drugs produce upon the healthy organism vary according to the dose. They may be:
1. CHEMICAL- depending on the chemical affinity which exists between the drug and the tissues of the body, and independent of vitality; or,
2. MECHANICAL (or revolutionary), consisting chiefly in violent efforts on the part of the organism to eject from its cavities the offending substance; or,
3. DYNAMIC, contingent upon vitality and resulting from the relations of the peculiar properties of the drug to the susceptibilities of the living, healthy organism. These dynamic effects may be:
A. Generic-such as are common to all the members of a certain class of drugs and which serve to distinguish this class from others, but do not furnish means of distinguishing between different individuals of the same class. For example, Arsenic in certain doses produces vomiting and diarrhoea, with cold sweat and cramps of the extremities. There are dynamic effects of Arsenic belongs, viz.: Cuprum, Veratrum, Tartar emetic, etc., in certain doses, produce identical symptoms; and were these remedies proved in such doses alone, it would be impossible to distinguish the pathogenesis of one of them from that of any of the others.
B. Specific- such as results from the dynamic action of the drug and are peculiar to it. They serve to distinguish a given drug from all others. For example, Arsenic, taken in different doses from those which produce the generic dynamic effects, produces vomiting and diarrhoea or tendencies thereto; but these phenomena are accompanied and characterized by conditions quite different from those which accompany the similar symptoms of Cuprum, Veratrum, etc., and are thus distinguishable from the effects of these drugs.
The Specific-dynamic symptoms may be again sub-divided into Central and Peripheral.
The Central symptoms appear speedily after the drug is taken, are generally the result of comparatively large doses and, in the case of many drugs, are confined to the alimentary canal and to the organs immediately connected with it.
The Peripheral symptoms appear more tardily, are generally the result of comparatively small doses, taken repeatedly or allowed to act without interruption for a long period, and appear in the bones, skin, glands, etc., and in the coordinated phenomena of life. They are often the manifestations of a dyscrasia or cachexy. Doses which produce central symptoms do not generally produce the peripheral (or at least not until after a long period has elapsed) and vice versa. For example, Mercury, in certain doses, produces well-marked and characteristic action upon the alimentary canal and its appendages. In smaller doses it produces, instead of these effects, a series of symptoms in the skin, bones, glands, etc. the Mercurial cachexy. The former are what we mean by central specific dynamic symptoms. The latter are the peripheral symptoms. Arsenic, again, furnishes, according to the dose, examples of all of the above varieties of symptoms. In certain doses if develops chemical and revolutionary effects. In smaller doses, as e have seen, generic dynamic; in still smaller doses, as we have seen, generic dynamic; in still smaller doses, specific dynamic symptoms of the central variety. In yet smaller doses, it produces peripheral specific symptoms, which are those of the so-called “gradual poisoning;” as for instance in poisoning by exhalations of Arsenic from green wallpaper, in which the phenomena of vomiting and diarrhoea or the central specific symptoms do not appear, but instead of these we have evidence of a distinct cachexy, in the skin and glandular symptoms, marasmus, etc.
Such are the varieties of symptoms produced by corresponding varieties in the dose. It is hardly necessary to say that they are nor always to be distinguished with precision; but the facility with which we are able to recognize them is in proportion to the completeness of our proving.
It unquestionably behoves the homoeopathic physician to have an exhaustive knowledge of the whole sphere of action of his drugs; but, as a prescriber, he must be familiar with the varieties and subvarieties of dynamics effects which we have specified. This knowledges is to be attained in the first place only by drug-proving. The proving of drugs must then be so conducted as to produce in the greatest possible completeness and clearness, each of these varieties and subvarieties. This, as has been shown, is to be accomplished by a skilful selection and succession of doses. It is not so simple and easy a matter as it might at first view appear to be: for,
First: The doses by which the corresponding varieties of symptoms are produced, differ widely in different varieties of example, a half grain of crude Nitrate of silver or of Sulphuric acid produces chemical symptoms, while a half grain of Lycopodium or of Silicea produces probably no symptoms at all. A grain of Arsenic produces generic dynamic symptoms, while ten grains of Natrum muriaticum may b inert. Forty drops of Bryonia tincture may excite a fair show of specific dynamic symptoms, while forty drops of tincture of Opium will produce generic dynamic symptoms or full narcotism.
Secondly: The susceptibility of different provers to the same drug is very different, and the degree of susceptibility which each prover possesses is to be learned only by experiment. For example, one prover will take five hundred drops of Thuja without any effect; another, taking twenty drops, experiences violent specific symptoms.
Thirdly: The susceptibility of provers to different preparations of the same drug is very various and apparently capricious. One record characteristic specific symptoms from large doses of the crude drug, and is not affected by smaller doses; another is acted on by dilutions and not by any quantity of the crude substance.
The relative power of a drug and susceptibility of the prover being altogether unknown until ascertained by direct experiment, the proving of a new drug is therefore a matter of pure experiment in every particular, and it might at first view be supposed to be a matter of indifference in what manner or with what doses the experiment is begun which variety or subvariety of symptoms is first developed, whether we take heroic doses and develop chemical symptoms or small doses and produce peripheral dynamic symptoms; since in either case we should be able by subsequent experiments based on the first, to develop the complementary symptoms and thus complete our proving. Experience teaches, however, that this supposition is not sound, and for the following reasons: Drugs vary not more in the intensity than in the permanence of their action upon the organism. Some drugs appear speedily to exhaust, sometimes by a single large dose, the susceptibility of the prover, so that no subsequent doses, whether large or small, produce any effect. Of others again, a single large dose develops some one generic or central specific symptom, and along with it induces such an exalted and distorted susceptibility that every subsequent dose, whether large or small, evokes straightway that one symptom or series of symptoms and none other. Thus the proving is in either case partial and incomplete-we fail to get those symptoms which are the most valuable of all to us, as being those which clearly characterize the drug and enable us to distinguish it from all other drugs, viz: the peripheral and central specific dynamic symptoms. To illustrate this point, it is well known that Mercury given in such doses as to produce central specific symptoms, induces often so great a susceptibility of the organism to the action of this drug that subsequent doses, even of tolerably high dilutions, provoke straight-way a series of central symptoms. The same is true of Arsenic. We have seen a case in which, generic and specific symptoms having once been produced by massive doses of Tartar emetic, the organism remained so sensitive to the action of this substance, that a few globules of the thirtieth dilution would at any time produce vomiting and diarrhoea, with cold sweat and prostration. It may be said that these are cases of very unusually great susceptibility to the action of the respective drugs. This is true, but it is precisely such cases of great susceptibility that are of exceeding value to us, for in them, by judicious experimentation, we could get most valuable peripheral symptoms, unalloyed by generic or by revolutionary effects.
There is no reason to believe, on the other hand, that small doses, so administered as to produce the peripheral specific symptoms, modify the susceptibility of the prover in any such way as to prevent his obtaining by subsequent larger doses the central specific, the generic dynamic, or even the chemical and mechanical effects. It follows from what has been said, that to obtain an exhaustive proving of a drug, we should begin with small doses, gradually increasing the quantity until unequivocal symptoms appear. We shall thus, if we continue our experiments a suitable length of time, obtain peripheral symptoms; and these small doses will not have so influenced the system as to prevent our obtaining by subsequent larger doses the other varieties of effects. Inasmuch as, in the nature of things, the peripheral symptoms, representing, as they do, a cachexy, cannot be speedily produced, a considerable space of time should be devoted to our first experiments with small doses. Finally, after an interval of non-medication, larger doses should be taken until we have exhausted the whole dynamic action of the drug, and even obtained a fair picture of its chemical and revolutionary action, although this may in a measure be gained from records of poisonings.
Dr. Dunham graduated from Columbia University with Honours in 1847. In 1850 he received M.D. degree at the College of Physicians and Surgeons of New York. While in Dublin, he received a dissecting wound that nearly killed him, but with the aid of homoeopathy he cured himself with Lachesis. He visited various homoeopathic hospitals in Europe and then went to Munster where he stayed with Dr. Boenninghausen and studied the methods of that great master. His works include 'Lectures on Materia Medica' and 'Homoeopathy - Science of Therapeutics'.