It would have been perfectly all right for Daniel to have crawled up to his garret atop the College and fallen asleep, but he felt that having been stupefied with opium for a night and a day ought to have enabled him to catch up on his sleep, and events in the Star Chamber and later in Hogs-den had got him rather keyed up. Any one of these three things sufficed to prevent sleep: the raw wounds around his neck, the commotion of the City coming awake, and his beastly, uncontrollable lust for Eliza. He went up-stairs to a room that was optimistically called the Library, not because it had books (every room did) but because it had windows. Here he spread out Eliza's letter on a table all streaked and splotched with disturbing stains. Next to it he set down a rectangle of scrap paper (actually a proof of a woodcut intended for Volume III of Newton's Principia Mathematica ). Examining the characters in Eliza's letter one by one, he assigned each to either the 0 alphabet or the 1 alphabet and wrote a corresponding digit on the scrap paper, arranging them in groups of five. Thus