In regard to many of the remedies which cure disease, it may be said, that we know not in what manner they do it. As an example I will refer to cinchona, and quinine, the essential principle of cinchona, in curing intermittent fever. The fact that they will cure it in most cases is as well established as any fact in medicine, but _how_ they do it no one knows. Many explanations have been ventured, but they are mere conjectures. Hahneman asserts, that cinchona and quinine cure intermittent fever on the homœopathic principle, because, as he declares, he has found, that these articles produce on persons in health symptoms similar to those of this disease. His experience, however, does not correspond with that of others, who are more competent to observe correctly, than one who looks at everything through the distorting medium of a favorite theory. Cinchona and quinine have been given to many persons in health, both in large and in small doses, in order to test the truth of Hahneman’s alleged experience, and no such results as he describes have followed. They seem to be singularly confined to Homœopathists. We see occasionally, but _only occasionally_, effects from agents in the treatment of disease which seem to have their explanation in the principle, that one disease is cured by temporarily creating another similar to it. Hahneman fixed his eye upon these few facts, his mind became filled with the _one idea_ which he there saw, and he was soon blind to everything else. Losing thus his mental equilibrium, he became an errorist precisely in the same way that thousands have done before him. The second great principle of Homœopathy is, that a peculiar power, a ‘dynamic power,’[15] as Hahneman calls it, is communicated to medicinal substances by minute division, with agitation and trituration. This Hahneman considers as his grand discovery. This was wholly an original idea with him, and if it be a really discovered _fact_ that a peculiar power is thus given to medicines, the credit belongs to him, and to him alone. The minuteness of the subdivision prescribed by Hahneman is extreme. He does not talk of doses so large as the millionth part of a grain—this would be horribly disastrous. A hundred millionth of a grain is quite a formidable dose. A decillionth is the common dose, and this numeral is expressed, after the old method of enumeration, by an unit with a string of _sixty_ cyphers. If we suppose the population of the earth to amount to a thousand millions, a grain, if taken in the dose of a decillionth of a grain, would supply every inhabitant of the earth with a septillion of doses. And if each one should take three decillionths of a grain a day, the present inhabitants of the earth would require very nearly a sextillion of years to use up the whole grain.