The story of another assassin follows: Leon Czolgosz. The man had a similar past to that of Guiteau, and planned to murder president William McKinley as to secure his own party's political candidate in the White House. He proceeded to shoot McKinley in the stomach and pancreas and was then sentenced to the electric chair. McKinley died of infection after eating when his stomach had not fully healed. Much to the anger of various neuroscientists and neurosurgeons alike, Czolgosz's brain was confiscated from study and destroyed. The experiments of Otto Loewi are also mentioned. His experiment was one in which he placed two frog hearts in separate cups of saline. He sped one heart up by triggering nerves, then transferred the saline of the fast heart into the saline of the normal beating heart, resulting in the normal heart being as fast as the other heart that he had triggered. This proved that neurons did not just use electricity, but also used chemicals. But since he realized that electricity could not jump the (tiny) distance between dendrites, he concluded that the electricity transformed into transferable chemicals. Chapter 3: Wiring and Rewiring Here, Kean introduces the eccentric James Holman. He was a blind explorer, a man who climbed mountains and visited all corners of the globe without sight. He was appointed the Naval Knight of Windsor, which was more illustrious than it sounded. Holman hated being home and often sank into deep bouts of depression when cooped up for too long a time. To get around during his journeys, he carried a cane. He did not use the cane like other blind people did, feeling around with it. He used his cane to strike the ground, causing a click that he could hear. This click, in turn, echoed in his ears, creating what was essentially human echolocation. Kean ties in Holman's use of his cane, to teach his brain to "see", with gray matter and white matter. He also talks extensively about circuits. Circuits essentially make up the brain, every human function being controlled by one. The circuits for breathing and yawning do not have much variation and are extremely simple. In contrast to that, the circuit that connects pictures to words, sounds to pictures (i.e. small children learning to read and associating the word dog with the actual animal) are more complicated. Negative experiences also wire circuits. A bad fright