654 THE POPULAR SCIENCE MONTHLY, 



able, for popular repute may vary widely from true professional 

 standing, and tlie 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 pro- 

 digious popular repiitations. 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 huij 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 profes- 

 sion ; a business in which money is to be made, decently and hon- 

 estly of course, but with no place in it for sentimentality or un- 

 selfish 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 /a-yor- 

 ahle evidence. To present, as expert ivitnesses, the whole argu- 

 ment, pro and con, is not their recognized function. They answer 

 certain questions, which have been carefully agreed upon before- 

 hand ; they evade opposing questions as far and as adroitly as 

 possible ; but science itself is not a client, and has no true repre- 

 sentative 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 feel- 

 ing is spread abroad that all its conceptions are fanciful and uncer- 

 tain. 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 mani- 

 fest 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 wit- 

 ness. The latter testifies to facts which, bearing directly upon 

 the case under trial, are part of his personal knowledge, inde- 

 pendently of all abstractions or. principles. He has seen a mur- 

 der 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 



