ASTR. You will drown us in a flood of Helicon, fair lady, if you thus dole out the thoughts of these maudlin poets. The records of national and domestic history, the dreams of the conqueror of thousands, and of the midnight assassin, are replete with incidents, if we will search for them, more impressive, ay, and more romantic, than all this rhyming; and from the legends of history alone I could select a legion of dreaming mysteries, which would dissolve all these fine-spun theories of Evelyn, regarding the _essence_, as he terms it, of the dream. He must adopt a clearer course, in showing us his _causes_, than by harping on this favourite theme of _memory_; and we must listen through another moonlight, ere we be made wiser, by the unfolding of this grand secret of visions. INFLUENCE OF DARK BLOOD IN THE BRAIN. “I talk of dreams, Which are the children of an idle brain.” ROMEO AND JULIET. EV. That I may explain to you the _predisposition_ of a dream,—in other words, the state of _broken slumber_,—it is essential that I recur to the physiology of the brain; and I must humble our pride, by combining some of the debasing conditions of our nature, as influential on the divine mind, through the medium of its _chambers of marrow_; for to the intimate condition and function of the brain and its nerves, and its _contained blood_, we must chiefly look for elucidation of the _physical causes_ of a dream. Yet I may even grant you, for an argument, Astrophel, the flight of an immortal spirit, and all the amiable vagaries of Sir Thomas Brown; reserving to myself to prove at what moment we become conscious of this flight. In natural actions, there are ever _three requisites_, like the points of a syllogism: 1. A susceptibility of influence; 2. The influence itself; 3. The effect of this influence: And these I call the _predisposing_, the _exciting_, and the _proximate_ causes. 1. The brain is brought to this susceptibility by excited temperament, study, intense and undivided thought; in short, by _any_ intense impression. 2. The influence or excitement is applied; congestion of blood producing impression on extremities, or origin of a nerve, at the period of departing or returning consciousness. At these periods, the blood changes, and I believe, _as it changes_, the phenomena of mind, as in the waking state, obey these changes:—rational and light dreams being the effect of circulation of _scarlet_ blood; dull and reasonless visions and “night-mare,” that of crimson, or _black_ blood. 3. The effect of this influence is recurrence of idea, _memory_,—more or less erroneously associated, as the blood approximates to the black or scarlet state, or as the brain itself is constituted.