* Baron Gerstorff, one of the provers so frequently mentioned in the Materia Medica Pura, has told me that Arsenic has been carried up to the 10,000th potency. - Hempel.

As it is impossible that the same dose or potency should be suitable to all patients, the question naturally occurs: What dose will excite the curative reaction of the organism in a sufficient degree? Every physician must feel interested in the settlement of this question, as the dose is of the utmost importance to a successful treatment. The lowest potencies, the thirtieth, and now the highest potencies, have been successively recommended as the normal doses. But we are convinced, from the many trials which we have made with every one of those preparations, that neither of them can be considered normal, and that the dose depends in every case upon the susceptibilities and the reactive power of the patient's organism. In Rau's Organon the conditions by which the dose ought to be determined have been accurately described, and we shall adopt them in the present work, so much more as the views of Rau on that subject coincide entirely with our own.*

* Note by Dr. Hempel. - Dr. Hartmann's remarks on the highest potencies appear to me rather superficial. If a man uses the 60th potency with as much success as he pretends to do, there is no good ground for his being astonished at the curative effects of the 200th or even the 2000th. Dr. Hartman denies that succussion is a means of developing the dynamic power of a drug; he thinks that attenuation by succussion is a simple process of dilution. In this I think he is grievously mistaken. How will Hartmann explain the fact that a drop of the tincture of Belladonna, when simply stirred in a glass of water, has frequently no effect, where a few pellets of the thirtieth potency will effect a speedy cure, or where a cure is effected by that same drop if it be mixed in a tumblerful of water by turning the solution some thirty or forty times from one tumbler into another, and then mixing a table spoonful of that solution with another tumblerful of water and turning this second solution again thirty or forty times from one tumbler into a second one 1 I can affirm that I have effected many cures with a double-attenuated solution where a simple dilution of the tincture left me entirely in the lurch. As regards the highest potencies, I protest both against their exclusive use and against the injudicious neglect with which many practitioners treat them. 1 have used them in many violent cases with the most perfect and sometimes with in- " stantaneous effect, and do use them now every day to my entire satisfaction. I have reported a number of cases in the Homoeopathic Examiner where the curative action of the highest potencies is so evident that no sane man can doubt it, and in many cases I have obtained results by means of the highest potencies where the lower potencies had entirely failed, even when administered by skilful hands. A few weeks ago I was requested to take charge of a lady who had been suffering with consumption brought on by mismanaged pneumonia. Her most distressing symptom was a hard wheezing cough with most difficult expectoration ; she had a turn every five minutes. This lady had been treated homceopathically for several months past, and the last medicine that had been given her was crude sulphur, of which she took three powders a-day, and had already swallowed twenty powders in all. The patient told me that her cough had been getting worse ever since she had taken those powders, and that her distress had become so excessive that she could not take the medicine any longer. Sulphur, however, was the remedy. I gave her two pellets of the 800th potency in water, a table spoonful every six hours, and when I saw her again, three days after, her cough was much less, the paroxysms were much less frequent and less violent. The lady remarked to me, " What a comfort it is to be able to sit without coughing."

In the second number of the Homoeopathic Examiner, Vol. IV., I have reported a case of neuralgic colic of upwards of three years' standing, which had been treated for eighteen months by the first homoeopathic physicians of this city. When I took charge of the patient, she suffered the most agonizing pain from morning till night, and the friends of the patient - a most interesting young lady - had given up all hope of ever seeing her relieved. I can affirm, as a man of honour, that that patient has not only been relieved but entirely cured, by the 200th potency of Ipecacuanha. I might adduce the written testimony of the patient's mother to show that the cure has been complete ; but I forbear on account of the flattering remarks contained in that paper.

Among other cases where the lower preparations have failed entirely and where the highest potencies have effected a cure, I may mention the following: - A gentleman of thirty years had an inflammatory rheumatic fever which was treated allopathically; in the course of the treatment he lost his appetite, his bowels became affected, and after the treatment had lasted a whole year he concluded to submit to homoeopathic treatment. His symptoms were : Constant uneasiness about the bowels, excessive qualmishness, constant desire to evacuate the bowels, which were very sluggish ; violent.

The susceptibility to medicinal influences is greatest in very small children and is at its acme in subjects entering upon pubescence, a period when the more noble developments take place. These are epochs when (as a general rule - Trans.) the organism requires but minute doses of medicine which ought to be so much more minute as the medicine has a specific relation to the organ. This observation is likewise applicable to females, who generally require smaller doses.

The constitution of the patient is likewise to be taken into consideration. Phlegmatic and torpid temperaments require the lower attenuations; sensitive persons, on the contrary, with a sanguine or choleric temperament, the higher. Persons whose sensibility has become obtuse in consequence of the abuse of spirituous and heating beverages, spices, piquant dishes, require larger doses of medicine to excite the necessary organic reaction. This shows that the mode of life has a great influence on the constitution. Mental labour, the reading of novels which excite the imagination, a sedentary and effeminate mode of life, and long sleeping, increase the sensibility; heavy labour, country-air, substantial and nutritious food, living in apothecaries, or tobacco-shops, distilleries, etc., diminish it. It is likewise certain that persons who have been treated with Lead, Mercury, Iodine, Cinchona, Valeriana, and other drugs, and are now suffering with a complication of the natural disease and medicinal poisoning, require larger doses than would have been necessary previous to such a poisoning having taken place.* Climate has also a powerful influence on the constitution, and indirectly upon the magnitude of the dose, as we know from experience.