IDIOTS SAVANTS. 235 



been educated to cipher, see tlie figures before us in computation. 

 Individuals who have been made to employ objects such as the 

 fingers, grain, pebbles, or the abacus visualize these objects in 

 their mental arithmetic. Indeed, the derivation of the word 

 calculation recalls the ancient use of pebbles in reckoning. A 

 psychological analysis of the mental operations required in cal- 

 culation is a difficult problem, the solution of which is very de- 

 sirable. Scripture, in his study of arithmetical prodigies, con- 

 cluded that the faculty of mental arithmetic, as exhibited in his 

 illustrative cases, depended upon 1. Accurate memory for a 

 sufficient length of time. 2. Velocity of memory. 3. Firmness 

 with which long series of arithmetical associations cling together. 

 4. Mathematical inclination. 5. Visualization. 



It will be noted that the fourth, the mathematical aptitude, is 

 the obscure factor, which the author did not attempt to explain, 

 and that the other four points are merely the means of expression 

 of the mathematical inclination. 



Musical Faculty. The susceptibility of all classes of idiots to 

 rhythmical sounds or noises has been frequently commented upon 

 by various authors. Music is the most sensual and the least intel- 

 lectual of the arts. A musical aptitude in certain idiots is there- 

 fore not so astonishing in some respects as the possession of the 

 arithmetical faculty. 



One of the most noted examples of idiots savants of this class 

 was Blind Tom, a pure negro, born in Georgia, in 1849. Born 

 blind, he showed intelligence only in regard to sound. He learned 

 to repeat words early, though the words had no meaning to him. 

 He could repeat whole conversations, but entirely without com- 

 prehension. His own spontaneous language was never much 

 more than inarticulate sounds. He could imitate any sound 

 about him. He could recite with ease anything heard in Greek, 

 Latin, French, or German. It was a species of echolalia. He 

 could play on the piano from memory any piece of music, no 

 matter how intricate, after hearing it but once. He would imi- 

 tate, note for note, the improvisations of another. He is said to 

 have retained as many as five thousand musical compositions in 

 his memory. 



Seguin describes (Idiocy, page 405) a blind male idiot with a 

 remarkable talent for piano-playing, with this same power of 

 repeating anything after a single hearing. 



Helat {La Folie lucicle) tells of a congenitally blind female 

 idiot with great musical talent. Her voice was correct, and when 

 once she had heard a piece she knew the words and the music. 

 This phenomenon excited so much attention that G^raldy, Liszt, 

 and Meyerbeer visited her. 



Dr. Paris (Lancet, February 11, 1888) records the case of an 



