honor bound, ask for a consultation in any case of serious sickness outside of their line of private practice, on the witness-stand put forth with the utmost boldness their ignorant crudities, careless or forgetful of the fact that they may be imperiling the life of an innocent human being.  On the trial of Mrs. Wharton for the attempted murder of Mr. Van Ness, Dr. Williams asserted that there are peculiar characteristic symptoms or groups of symptoms of tartar emetic poisoning;[13] and both he and Dr. Chew—­who with frankness acknowledged that he had not especially studied toxicology—­did most positively recognize tartar emetic as the sole possible cause of certain symptoms which were but a little beyond the line of medicinal action, and for which obviously possible natural cause existed.  Contrast these bold opinions with the cautious statement of a man who had given a lifetime of study to this particular subject.  On the trial of Madeleine Smith, Professor Christison—­at that time the first toxicologist of England—­stated that if in any case the symptoms and post-mortem appearances corresponded exactly with those caused by arsenic, he should be led to suspect poisoning.

Another source of mischief lies in the fact that the law does not recognize the well-established principles of forensic medicine, and consequently the books in which these principles are laid down by the highest authorities are excluded by the courts, while the viva voce evidence of any medical man, however ignorant on such points, is admitted as that of an expert.

It is therefore not to be wondered at that juries give but little consideration to the knowledge or professional standing of expert witnesses.  It is, in fact, notorious that the medical autocrat of the village, who has superintended the entrance of the majority of the jurymen into this troublous world, is a more important witness than the most renowned special student of the branch:  indeed, the chief value of the real expert often rests on his ability to influence the local physician.[14] At the late Wharton-Van Ness trial the defence desired to show that the work of the chemist employed by the prosecution was unreliable, because the analyses made by him in a previous case had “been condemned by the united voice of the whole scientific world.”  The court was not able to see the relevancy of this, and refused to allow the professional ability or standing of an expert to be called in question.  The witness thus adjudged competent brought no results into court; had kept no laboratory notes; relied solely on a memory so deficient that although he had been teaching for thirty-five years, he could not tell the shape of a crystal of tartar emetic, the poison in question; and upon the stand made a statement different from one which he had furnished officially to the district attorney of Baltimore fourteen months before.