It appears, also--and the fact is very remarkable--that a similar kind of sensation will produce the same description of dream in a number of individuals at the same time. Hence different people will sometimes have the same dream. We read of a whole regiment starting up in alarm, declaring they were dreaming that a black dog had jumped upon their breasts and disappeared, which curious circumstance was explained by the discovery, that they had all been exposed to the influence of a deleterious gas, which was generated in the monastery. The effect of music, also, in exciting delightful dreams, has often been attested. A French philosopher whose experiments are reported by Magendie, according to the airs which he had arranged should be played while he was asleep, could have the character of his dreams directed at pleasure. "There is an art," says Sir Thomas Browne--in his usual quaint style--"to make dreams as well as their interpretations; and physicians will tell us that some food makes turbulent, some gives quiet dreams. Cato, who doated upon cabbage, might find the crude effects thereof; and Pythagoras might have had calmer sleeps if he had totally abstained from beans." The influences of the day's occurrences, and the thoughts which have occupied the mind during the day, have been said to give a corresponding tone and coloring to our dreams at night. Thus the lover dreams of his mistress; the miser of his gold; the merchant of his speculations; the man of science of his discoveries. The poets of all ages and nations adopt this view. Virgil describes Dido forsaken by Æneas, wandering alone on a desert shore in pursuit of the Tyrians. Milton represents Eve relating to Adam the dreams which were very naturally the repetition of her waking thoughts. Petrarch invokes the beauty of Laura. Eloisa, separated from Abelard, is again happy in his company, even amid the "dreary wastes" and "low-browed rocks."