Besides the constituents, the preparations, and the pharmacology of a drug, we are to learn its therapeutics, and we might ask how have our drugs come to have their present uses in medicine?

From the employment of hepatica for liver diseases because its leaf suggested the liver, to the employment of drugs because of known actions determined by animal experimentation and therapeutic tests is a far cry, yet it represents only a few years of time, and indicates the rapid strides that are being made toward the establishment of therapeutics on a sound scientific basis. The use of drugs without an adequate scientific explanation of their efficiency is empiric. For instance, colchicum is extensively employed as a remedy in gout, though no pharmacologic study has as yet indicated how or why colchicum should be of benefit in this disease. We give it in gout for no other reason than that we believe that it has worked before; in other words, we use it empirically.

As a matter of fact, animal experimentation is rapidly relegating empiric remedies to the realm of disuse or giving them new uses; and many beliefs in the efficacy of remedies have yielded to the adverse proof of experiment. Indeed, very few of the advances of the last half-century could have been made but for the use of animals in the study of the action of drugs, for detailed experiments on human beings are obviously out of the question. Anrep, working with animals, discovered the effects of cocaine as a local anesthetic; antipyrine, phenacetin, and a number of so-called coal-tar products owe their use to an observation by Filehne that antipyrine reduced the temperature of animals put into fever by experimental infection. The actions of nitrites, of thyroid extract, of saline infusions, of diphtheria antitoxin, etc., are all known as the result of animal experiments.

In this connection it is an interesting fact that many of the most important discoveries have resulted from purely academic studies, studies made without thought of finding substances useful to man. For example, the hypnotic power of chloral hydrate was the outcome of Liebreich's attempt to solve the purely physiologic question as to whether or not a substance is broken up into its constituent parts before it is oxidized. The sleep-producing power of sulfonal was discovered in a study of the effects of organic sulphur compounds on metabolism. The power of epinephrine to constrict the arteries and raise blood-pressure was first noted in animal experimentation conducted with no thought of therapeutic possibilities. And the recent wonderful additions to our knowledge of the irregularities of the heart may be attributed largely to some incidental observations of Cushny and others while performing laboratory experiments without a thought of their ultimate usefulness to man.

These illustrations suggest what important discoveries might be lost to us if animal experimentation were to be undertaken only with the definite object of lessening human ills. If to these therapeutic agents which we owe to experiments on animals we add the knowledge of the body processes, of disease conditions, of the transmission of disease, and of the development of immunity, it makes enormous the sum of the obligations of medical science and human sufferers to animal experimentation, commonly known as vivisection. Yet in recent years a goodly number of people who profess to believe that no animal should be sacrificed for the good of human beings, have made the most strenuous efforts to bring about legislation restricting vivisection. Their harrowing descriptions of experiments, their grossly exaggerated statements as to the failure of experimenters to protect the animals from pain, and as to the brutality of the experimenters themselves, have, unfortunately, led many people of prominence to give them support, and have made it incumbent upon all physicians who are in a position to know the facts to combat in every way this retrograde movement. The medical man, of all persons, is in the best position to realize how, in the absence of vivisection to establish exact data, every attempt to treat the sick, especially by the new medical graduate, "would be nothing less than an experiment in human vivisection, which animal experimentation now renders needless."