In a conversation with his physician, a nineteenth-century resident of Paris who lived near the railroad described sensations of brilliant color generated by the sounds of trains passing in the night. This patient-a synaesthete-experienced color hearing for letters, words, and most sounds. Synaesthesia, a phenomenon now known to science for over a century, is a rare form of perception in which one sense may respond to stimuli received by other senses. This fascinating book provides the first historical treatment of synaesthesia and a closely related mode of perception called eideticism. Kevin...