_Delirium, artificial._--The most common of these forms of disordered mental action is that transient and artificial state produced by intoxicating drugs and drinks. This is properly called delirium, and takes place whenever total or even partial inebriation occurs, whether from alcoholic or narcotic stimulants, as the opium of the Chinese, and the Indian hemp or _hachish_ of the Hindoos. The same effects, substantially, are produced, also, by certain plants, as the deadly night-shade and others, and also by aconite. In all these cases the effect is wrought primarily, it would seem, upon the blood, which is brought into a poisonous state, and thus deranges the action of the nerves and the brain. The _hachish_ or Indian hemp, which, in the East, is used for purposes of intoxication more generally, perhaps, than even opium, or alcoholic drinks, may serve as an illustration of the manner in which these various stimulants affect the senses. At first the subject perceives an increased activity of mind; thoughts come and go in swift succession and pleasing variety; the imagination is active--memory, fancy, reason, all awake. Gradually this mental activity increases and _frees itself from voluntary control_; attention to any special subject becomes difficult or even impossible; ideas, strange and wonderful, come and go at random with no apparent cause and by no known law of suggestion; these absorb the attention until the mind is at last given up to them, and there is no further consciousness of the external things, while, at the same time, the patient is susceptible, as in the magnetic state, of influence and impression from without. How closely, in many respects, this resembles the state of the mind in somnambulism, mesmerism, and ordinary dreaming, I need not point out. The mental excitement produced by opium is perhaps greater, and the images that throng the brain, and assume the semblance of reality, are more numerous and real. The subsequent exhaustion and reaction in either case are fearful. For illustration of this the reader is referred to the Confessions of an Opium Eater, by the accomplished De Quincey.