What is thus exemplified in astronomy and astrology can be found in the story of every other science. After the knowledge of the stars, the next organized branch of information that might deserve the name of science related to plants. This, too, was introduced into medicine, and with more justification than astrology. Most of what was accomplished by early herbal medicine was, however, due to the influence produced on the mind rather than to any physical influence tending to correct pathological conditions. The shape and color of plants, their form, the appearance of their leaves, were all supposed to indicate medical applications for human ailments. The reason for their acceptance was entirely the ideas associated with the plants and not any definite therapeutic effect. Whatever good nine-tenths of all the herbal medication accomplished certainly was by means of the influence on the mind. We have abandoned the use of most herbal remedies in recent years, even many that are still retained in the pharmacopeia, because we have realized their physical incapacity for good. ALCHEMY When chemistry, under the old name of alchemy, began to develop, its first study was of minerals, and just as soon as a body of knowledge was acquired chemistry was applied to medicine. All the investigators were engaged in searching for the philosopher's stone, the substance by means of which it was hoped to change base metals into precious. It was generally believed that when this substance was found, it would have wonderful applications to human diseases and would transmute diseased tissues into healthy tissues in the same way that it transformed metals. It was felt that the philosopher's stone would be an elixir of life as well as a master of secrets for wealth. This would seem amusingly childish to us were it not for the fact that in radium we, too, seem to have discovered a philosopher's stone--a substance that transmutes elements. For some years after its discovery {41} we were inclined to think that it must have some wonderful application in medicine and in surgery, and we actually secured many good results until its suggestive value wore off. The fact that much had been learned about chemicals persuaded men that they must be beneficial to human beings. Thus they were taken with confidence and produced good results. When our modern chemistry developed out of alchemy a great variety of drugs began to be used, and long, complex, many-ingrediented prescriptions were written. Polypharmacy became such an abuse that the time was ripe for Hahnemann, whose principles, if carried to their legitimate conclusions, would require his disciples to give practically nothing to patients and treat them entirely by suggestion. MATHEMATICAL MEDICINE