According to evidence at the trial, it is probable that Lamson had made several previous attempts on the lad's life, with aconitine, in the form of pills and powders, which he had given him under the pretence of prescribing for his ailments. The money to which he was entitled on the death of John doubtless supplied the motive for the crime. The proof of the purchase of aconitine by the prisoner, and the evidence of the post-mortem examination, pointed to the cause of death, and the presence of aconitine was amply proved by the clinical and other tests patiently and carefully applied by the analyst. The difficulty of proving the presence of a rare vegetable alkaloid in the body after death was, no doubt, duly considered by Lamson when he fixed on aconitine as the medium for his evil design; but science proved the master of the criminal, and the evidence of the instrument by which the crime was committed was indisputably proved. CHAPTER XII THE BRAVO MYSTERY ANTIMONY, like arsenic, to which in many ways it is closely allied, claims also to be ranked among the historic poisons. It was known and used by the ancient Greek and Roman physicians as a medicinal agent, and for certain purposes it is, perhaps, unequalled at the present time. The metal is a brittle, silvery and very brilliant substance, in the form of plates and crystals, and is largely used in the arts as an alloy, the most common form being Britannia metal, which is a compound of antimony, lead, and tin. The old _Poculo emetica_ or everlasting emetic cups, were made of antimony. It is found abundantly in nature as a sulphide, also combined with various metals, and with quartz and limestone. From these it is separated by fusion, the heavy metallic portion sinking by the law of gravity, and abandoning the impurities which remain on the surface of the molten mass. Arsenic is a frequent contamination of commercial antimony, and it is very important that it should be eliminated before antimony is prepared for use in medicine. Poisoning by tartarated antimony causes a peculiar metallic taste in the mouth, which is speedily followed by vomiting, burning heat, pains in the stomach and purging, difficulty in swallowing, thirst, cramp, cold perspirations, and great debility. In smaller doses it produces these effects in a mitigated form, which causes symptoms somewhat similar to natural disease, such as distaste for food, nausea, and loss of muscular power. For this reason, doubtless, it has been a favourite medium with many criminal poisoners, including Dove, Smethurst, Pritchard, and others; but there is no trial in which antimony has figured that caused more interest than the "Bravo Mystery" of 1876.