lated combines to prove, that Mercutio, in "Romeo and Juliet," was scientifically correct when he said:
True, I talk of dreams,
Which are the children of an idle brain,
Begot of nothing but vain fantasy.
Nightmare, with all its horrors, is but a variety of dream. The causes for its peculiarities are various—position; pressure upon the stomach, whereby the sympathetic nerves are affected, and through them the brain; extreme fatigue, etc. When one is awake and has precisely the same unfavorable physical sensations which would produce nightmare, he refers them to their proper source, changes his position, measures the probable consequences, resorts to medical aid, or absorbs himself in work; but when asleep, the mind attempts to account for the sensation, and will perhaps construct an image of Bunker Hill Monument pressing upon his chest to account for a sensation which, if he were awake, he would have no difficulty in explaining.
The relation to nightmare of sleeping on the back is so simple as hardly to need an explanation. Many persons never have an attack unless they get into this position.
Somnambulism differs from dreams in the fact that one or more of the senses may be in an active condition, and that one or more of the organs may respond to the idea which absorbs the mind. A merchant in New York, traveling on the Mississippi River, occupied the same state-room with a stranger of highly respectable appearance. In the morning the stranger, taking up his stockings, said sadly, "I see I have been at my old tricks again." "To what do you refer?" asked the merchant. "My stockings are wet, and I
