FOREWORD
Except for its characters and plot, this book is not a work of the imagination.
The methods which the fictitious Trant—one time assistant in a psychological laboratory, now turned detective—here uses to solve the mysteries which present themselves to him, are real methods; the tests he employs are real tests.
Though little known to the general public, they are precisely such as are being used daily in the psychological laboratories of the great universities—both in America and Europe—by means of which modern men of science are at last disclosing and defining the workings of that oldest of world-mysteries—the human mind.
The facts which Trant uses are in no way debatable facts; nor do they rest on evidence of untrained, imaginative observers. Innumerable experiments in our university laboratories have established beyond question that, for instance, the resistance of the human body to a weak electric current varies when the subject is frightened or undergoes emotion; and the consequent variation in the strength of the current, depending directly upon the amount of emotional disturbance, can be registered by the galvanometer for all to see. The hand resting upon an automatograph will travel toward an object which excites emotion, however capable its possessor may be of restraining all other evidence of what he feels.
If these facts are not used as yet except in the academic experiments of the psychological laboratories and the very real and useful purpose to which they have been put in the diagnosis of insanities, it is not because they are incapable of wider use. The results of the "new psychology" are coming every day closer to an exact interpretation. The hour is close at hand when they will be used not merely in the determination of guilt and innocence, but to establish in the courts the credibility of witnesses and the impartiality of jurors, and by employers to ascertain the fitness and particular abilities of their employees.
Luther Trant, therefore, nowhere in this book needs to invent or devise an experiment or an instrument for any of the results he here attains; he has merely to adapt a part of the tried and accepted experiments of modern, scientific psychology. He himself is a character of fiction; but his methods are matters of fact.
THE ACHIEVEMENTS OF
LUTHER TRANT