Read it through once

_11 p. m._--I gave Renfield a strong opiate to-night, enough to make even him sleep, and took away his pocket-book to look at it. The thought that has been buzzing about my brain lately is complete, and the theory proved. My homicidal maniac is of a peculiar kind. I shall have to invent a new classification for him, and call him a zoöphagous (life-eating) maniac; what he desires is to absorb as many lives as he can, and he has laid himself out to achieve it in a cumulative way. He gave many flies to one spider and many spiders to one bird, and then wanted a cat to eat the many birds. What would have been his later steps? It would almost be worth while to complete the experiment. It might be done if there were only a sufficient cause. Men sneered at vivisection, and yet look at its results to-day! Why not advance science in its most difficult and vital aspect--the knowledge of the brain? Had I even the secret of one such mind--did I hold the key to the fancy of even one lunatic--I might advance my own branch of science to a pitch compared with which Burdon-Sanderson’s physiology or Ferrier’s brain-knowledge would be as nothing. If only there were a sufficient cause! I must not think too much of this, or I may be tempted; a good cause might turn the scale with me, for may not I too be of an exceptional brain, congenitally?