I Sociologists have long been debating the theory that the impulse to commit crime is a disease, and the ayes appear to have it—the disease. It is gratifying and profitable to have the point settled: we now know where we are and can take our course accordingly. It has for a number of years been known to all but a few old physicians—survivals from an exhausted _régime_—that all disease is caused by bacilli, which worm themselves into the organs that secrete health and enjoin the performance. The medical conservatives attempt to whittle away the value and significance of this theory by affirming its inadequacy to account for such disorders as broken heads, sunstroke, superfluous toes, home-sickness, burns and strangulation on the gallows; but against the testimony of so eminent bacteriologists as Drs. Koch and Pasteur their carping is as that of the idle angler. The bacillus is not to be denied; he has brought his bedding and is here to stay until evicted. Doubtless we may confidently expect his eventual eviction by a fresher and more ingenious disturber of the physiological peace, but the bacillus is now chief among ten thousand evils and it is futile to attempt to “read him out of the party.” It follows that in order to deal intelligently with the criminal impulse in our afflicted fellow-citizens we must discover the bacillus of crime. To that end I think that the bodies of hanged assassins and such persons of low degree as have been gathered to their fathers by the cares of public office or consumed by the rust of inactivity in prison should be handed over to the microscopists for examination. The bore, too, offers a fine field for research, and might justly enough be examined alive. Whether there is one general—or as the ancient and honorable orders prefer to say, “grand”—bacillus, producing a general (or grand) criminal impulse covering a multitude of sins, or an infinite number of well-defined and several bacilli, each inciting to a particular crime, is a question to the determination of which the most distinguished microscopist might be proud to devote the powers of his eye. If the latter is the case it will somewhat complicate the treatment, for clearly the patient afflicted with chronic robbery will require medicines different from those that might be efficacious in a gentleman suffering from sporadic theft or a desire to represent his district in the Assembly. But it is permitted to us to hope that all crimes, like all arts, are essentially one; that murder, arson and conservitude are but different symptoms of the same physical disorder, at the back of which is a microbe vincible to a single medicament, albeit this awaits discovery. In the fascinating theory of the unity of crime we may not unreasonably hope to find another evidence of the brotherhood of man, another spiritual bond tending to draw the several classes of society more closely together. II