All vegetable poisons, except the alkaloid of strychnia, decompose with the body; it is extremely rare that any alkaloid can be discovered in the body posthumously. Mineral poisons, such as antimony, lead, copper, combinations of baryta, and many others, are indestructible, and can be detected in the ashes. It may even happen that, by some extra care, the process of incineration may be the most efficient means of detecting poisoning by arsenic and mercury. Of course we should not forget that, without some precaution, the salts of arsenic and mercury would be volatilized; but while they are volatilized, they must also, at a reduced temperature, be again deposited, and it remains for the chemist to determine the most efficient contrivance for recognizing its deposition. Direct experiments instituted by M. Cadet and verified by MM. Doursant and Wurst, even prove that the salts of arsenic can be detected in the ashes after incineration. As matters stand to-day, it is puerile to think that we can prevent the rich and skilful poisoner from committing crime as long as we permit him to employ undertakers, who, without restraint of law, inject arseniate of soda and corrosive sublimate into the body of his victim, and thus remove all traces of the crime. Dr. Cameron, in a speech before the House of Commons of England in 1884, declared:— “Numerous modern researches have shown that putrefactive fermentation in decaying animal matter gives rise to the formation of sepsine and other alkaloids, some of them intensely poisonous. Little or nothing is known in this country concerning the products of putrefaction. _Ptomaines_ is the general name which has been given to them abroad, and I don’t know that I ever saw it printed in the English language. Little is known of these ptomaines even by those who have studied them most closely, but enough has been discovered to show that we must be very careful as to how far we rely upon what are called physiological tests for poisons in the case of bodies which have been exhumed; and that the fact that frogs, rabbits, or dogs are killed by the action of matters extracted from the viscera of a putrefying body can no longer by itself be held as proving that those viscera contained any poison before putrefaction commenced.” Is it surprising, when the above is taken into consideration, that the testimony of chemists at trials for poisoning should vary so much and be so contradictory in nature? Sir Henry Thompson, in his admirable exposition of cremation, which was translated into almost every civilized language of the world, thus disposes of the medico-legal objection:—