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Through one or more of the above modes of operation all poisons may be said to produce their fatal effects. In some cases a poisonous substance will be found to act in several different ways; thus, the Nightshade is evidently absorbed, carried into the circulation, and is enabled, through that medium to act upon the brain; at the same time it exerts a local action upon the stomach, although less violent than that occasioned by the acrid poisons; it moreover would appear, upon some occasions, to act directly through the medium of the nerves, like those substances which have been received in our first class, or else, how shall we explain the fact of the pupil of the eye becoming permanently dilated by the contact of the Belladonna with the tunica conjunctiva? It would appear therefore that this plant unites within itself all the three great modes of action, upon which I have just attempted to establish a physiological arrangement of Poisons. So again, Corrosive Sublimate, although placed in the fourth division, as being a substance which destroys by inflicting local mischief, is nevertheless capable of being absorbed. The embarrassments, however, which might be supposed to arise from this double mode of operation, are of but trifling importance. It is to the primary operation of a poison to which we are to direct our attention, the subsequent effects are less important in as much as they are more capable of being controlled.