species of poisoning, and the magistrates accordingly consulted the College of Medicine of Copenhagen, who decided the question in the affirmative, having first instituted a series of experiments upon horses. Death may also be produced by the introduction of arsenic into the rectum; it is said that Sir _Thomas Overbury_, after the failure of the various poisons[231] that were administered to him, was at last despatched by an arsenical glyster. With respect to the quantity of arsenic required for the production of such effects it is difficult to offer a decided opinion, as its operation must in every case be liable to contingency; but a very few grains are in general amply sufficient. _Physiological action of Arsenious Acid._ It had long been supposed that arsenic occasioned death by inflaming the stomach; but Mr. _Brodie_[232] has very satisfactorily proved, that its influence arises from its being absorbed, and that it must be regarded as a _vital_ rather than as a _chemical_ agent, and as having a constitutional, not a local mode of operation. In the first place, he has in many instances found the inflammation of the stomach so slight,[233] that on a superficial examination it might have been easily overlooked; and in most of his experiments with arsenic, death took place in too short a period to be considered as the mere effect of inflammation. In the next place we have already shewn that in whatever manner the poison is applied, whether _externally_ to a wound, or _internally_, to the alimentary canal, the same inflammatory appearance will be visible in the stomach; a fact which can only be explained by admitting that the poison is absorbed, and that it acts upon these organs through the medium of the circulation; it acts at the same time upon the brain, and heart, but with different degrees of force in different cases; so that it is sometimes difficult to ascertain which of these organs is the first to fail in its functions. According then to these experiments and observations, inflammation of the alimentary canal is not to be considered as the general cause of death in poisoning by arsenic; and yet cases will occur, where the local affection may prove fatal, the animal having survived the effects produced on the organs more immediately subservient to life, as the brain and heart. Mr. _Henry Earle_ communicated to Mr. _Brodie_ a case highly illustrative of this fact, which occurred in St. Bartholomew’s hospital; a woman had taken arsenic, and having recovered from the alarming symptoms which first occurred, died at the end of four or five days, when upon dissection, there appeared extensive ulcerations of the stomach and bowels. This then was evidently a case of “_Consecutive_” poisoning.