able, for popular repute may vary widely from true professional standing, and the quack is often better known to the world at large than the man of really solid attainments. There are quacks in science, just as elsewhere, and these men sometimes have prodigious popular reputations. One of them, widely known as an expert in the courts and on the certificates of patent-medicine venders, was once called upon to analyze a commercial product. "Do you want this sample analyzed to buy or to sell?" was his modest inquiry! Still another class of experts, having creditable standing among their fellows as regards knowledge and ability, is made up of men to whom a science is a trade rather than a profession; a business in which money is to be made, decently and honestly of course, but with no place in it for sentimentality or unselfish devotion to abstract principles. They enter the court-room, as do the lawyers, to win cases for their clients; not by unfair means or trickery, but by the strongest presentation of the favorable evidence. To present, as expert witnesses, the whole argument, pro and con, is not their recognized function. They answer certain questions, which have been carefully agreed upon beforehand; they evade opposing questions as far and as adroitly as possible; but science itself is not a client, and has no true representative in the court.
It goes almost without saying that, if science is to grow and flourish, it must be esteemed and respected by the community. Its advocates, therefore, to protect themselves, must oppose every policy which tends to its disparagement. Nearly every trial in which experts are called is harmful to the interests of science, for its supposed representatives too often forget their duty, and a feeling is spread abroad that all its conceptions are fanciful and uncertain. The disputes of litigation do not add to its dignity. It is, of course, impracticable to abolish expert testimony, even of the crudest and most venal kind; for each side in a suit has the manifest right to submit whatever evidence it can get in its own favor. The problem is, to modify the evil, and to reduce its influence to a minimum. How can this best be accomplished?
From what has already been said it will be easily seen that the position of an expert is different from that of an ordinary witness. The latter testifies to facts which, bearing directly upon the case under trial, are part of his personal knowledge, independently of all abstractions or. principles. He has seen a murder committed, he identifies a person or a signature, he met a certain man at a certain time or place, and the like. On most of these points the testimony of the most ignorant laborer is as good as that of the highest scholar, for they relate to the narrowest and simplest kinds of experience, and involve no mental training whatever. The expert, on the other hand, is nearer akin to the
