The Psychology of Poisoning. Another surprising feature of these cases is the fact that in each of them some of the most important proof was furnished by the defendant herself. They confessed in writ ing, they wrote letters, and they bought arsenic without disguise.. It seems extraor dinary that Mrs. Maybrick and Miss Blandy should have written as they did to their lovers if they were innocent; it seems still more extraordinary if they were guilty. So it seems almost incredible that three of them should have bought arsenic in their own names just before the fatal act, if they were guilty of the act. Finally, we must note as a remarkable fact the tendency of the jury to convict. In the case of most murders where the evidence is so evenly balanced and public opinion so strongly favors the defence, the jury almost invariably acquits; but the result of these cases, so far as it goes, justifies the inference of a bias in the jury against one accused of poisoning. So far as other cases have been examined, they strengthen this inference. In Miss Smith's case, where the verdict was "not proven," the jury were doubtless influ enced by the popular dictum, if she did not poison him she ought. Bear in mind the fact that the defendants here were all attract ive women, whose conduct at the trial was all in their favor, and their conviction is really extraordinary. It is probable that poison is so secret and so terrible an agent, that even a suspicion of its use prejudices a jury against the accused, and in fact though not in law shifts the burden of proof. Conviction in these cases was the more remarkable because in most of them another probable agency of poisoning was pointed out by plausible evidence. It seems fair to say that in almost every case, taken by itself, the evidence introduced did not prove guilt bevond a reasonable doubt, and the verdict
of guilty was therefore not justified. If the crime under investigation had been com mitted by a less secret and dreaded agency than poison a verdict of not guilty would probably have been rendered in every case. Shall we then be forced to conclude that the women who have thus suffered convic tion were innocent? Probably not. Though in each case the crime was not proved beyond a reasonable doubt, in every case the scale of probability inclined toward guilt. Taken separately, the evidence in each case does not prove guilt; but when the cases are studied together the conviction of guilt is forced upon one. . The constant iteration of the typical cir cumstances indicates some law of action to which all conform; a law which must take its origin from some common spring and course of action in these women. So far as such a law can be regarded as established by the examples we have studied (which are confirmed by all the cases of arsenical poi soning by women that the author has been able to find reported), it furnishes a clue to the causes of phenomena observed in new cases. If such a study had been made by an expert psychologist before the Maybrick case, and he could under the laws of evi dence have given his opinion of the guilt of the defendant, he would doubtless have expressed it in the affirmative. He would have pointed out, first, that the woman was in love with a man not her husband, and feared detection; that she cared tenderly for her husband and always controlled herself, yet could not forbear writing to her lover; that the supposed poison was used in such small quantities as almost to defy detection. On such opinion evidence, if the judge could properly have left it to the jury, a conviction would have been justified.
