First, as to the supposed harmlessness of vegetable medicines. The most active mineral medicines are arsenic and corrosive sublimate. But arsenic taken in large quantity never produces death in a shorter time than five to ten hours, and a large dose of corrosive sublimate destroys life ordinarily in from twenty-four to thirty-six hours. But among vegetable substances, oxalic acid, found in the common wood sorrel, has destroyed life in ten minutes, and prussic acid, which is the bitter principle in wild cherry, bitter almonds, peach blossoms, &c., in the dose only of a few drops, destroys life instantly. Comparisons might be made still further, showing that the most deadly and expeditious poisons are vegetable. Let us look now at the comparative _duration_ of the results of vegetable and mineral medicines. Much is said, especially by Thompsonians, about calomel’s staying in the system, and all the bodily ills of a life-time are often attributed to this cause without any hesitation. Whether these wise ones have ever applied their rude chemistry to the detection of calomel in such cases I have not learned. But there it is, _for they say so_. It is in the very bones! Though no intelligent persons believe in such nonsense as this, yet the general notion that the effects of mineral, in comparison with vegetable agents, are peculiarly abiding, is not confined to the ignorant and unthinking. Leaving out of view the direct corrosive effects upon the living texture of the concentrated acids, I may remark of poisons, whether mineral or vegetable, that they produce either morbid _impressions_ upon the system through the nerves with which they come in contact, or local _irritations_, which may result in inflammation. These impressions or irritations may abide, or they may be partially or wholly removed. The fact that they are produced by a mineral is no more apt to make them abide, than the fact that they are produced by a vegetable. We should expect this to be true, and experience has shown that it is. For example the irritation produced by elaterium (wild cucumber) or croton oil, or any vegetable cathartic of a drastic nature, is as lasting as if it had been caused by any mineral poison.