tomed to read and imagine spoken oratory, can be accounted for without assuming that he dreamed of hearing sounds, the speech-making being a movement of his mind involving an act rather than a perception. The being wakened by the explosion of firearms is, as Professor Chickering justly says, explicable on the same principle as that which accounts for the awaking of the deaf and the communication of information by the rhythmical vibration of a building.
Leaving out of account the question of the dreamless state of infants and very young children, I deem the facts that animals dream, that the congenital blind and deaf never dream of seeing or hearing, conclusive proof that dreams are phenomena of the physical basis of mind, dependent upon changes in the circulation of the blood, and the condition of the brain and the nervous system; and that images constructed in dreams are automatic combinations of the sensations, experiences, ideas, and images stored in the mind.
Three further collateral evidences can be adduced. First, the modification of dreams by physical conditions. With this all are familiar. These are plainly, so to speak, efforts of the image-making faculty active in dreams to account without the aid of the judgment for a physical sensation. Every one knows that the condition of the digestive organs, the position of the head or any other part of the body, will affect dreams.
Another fact is that the dreams of the very aged, unless something unusually agitating is anticipated or occurs, generally recur to scenes of former years, and therein greatly resemble their conversation. Even when the intellectual faculties are unimpaired, and the aged person is much interested in current events, and pursues a train of study and reflection by day
