EDITOR'S TABLE. 



237 



six must begin some time to turn oftener." 

 On the contrary, if, after the twentieth 

 throw, it turns up exactly one-sixth of the 

 times, its frequency approximates indefi- 

 nitely in the long run toward one-sixth. 



The table given in the April number, p. 

 715, shows that, as the number of throws 

 increases, the difference between the num- 

 ber of sixes and one-sixth of the number of 

 throws generally increases, being propor- 

 tional to the square root of that number; 

 at the same time the difference between the 

 proportion of sixes and one-sixth generally 

 decreases, in the same proportion that the 

 discrepancy of the number increases. 



In 6 throws, the number of sixes will 

 probably lie between and 2 ; the propor- 

 tion between and 0.3333. . . 



In 60 throws, the number of sixes will 

 probably lie between 8 and 12; the propor- 

 tion between 0.133 and 0.200. 



In 600 throws, the number of sixes will 

 probably lie between 93 and 10*7 ; the pro- 

 portion between 0.155 and 0.178. 



In 6,000 throws, the number of sixes 



will probably lie between 980 and 1,020 ; 

 the proportion between .163 and .170. 



In 60,000 throws, the number of sixes 

 will probably lie between 9,938 and 10,062 ; 

 the proportion between .1656 and .1677; 

 and so on. 



All this relates to independent events ; 

 that is, those of which the occurrence of 

 one neither increases nor diminishes the 

 probability of the occurrence of another. 

 If an urn contains a number of balls, of 

 which one-sixth are black and the rest 

 white, every drawing of a black ball de- 

 creases the relative number of black balls 

 among those which remain. If there were 

 but one hundred and twenty balls in all, at 

 first, and the first twenty drawn were black, 

 it becomes absolutely certain that all the 

 remaining drawings will be of white balls. 

 The greater the total number, however, the 

 less influence will the run of twenty black 

 drawings have upon those which follow; 

 and, if the total number were endless, the 

 case would be similar to the repeated 

 throwing of a die. 



EDITOR'S TABLE. 



THE STUDY OF THE BRAIN. 



THE recent activity of psychological 

 study, and the many valuable re- 

 sults arising from it, induced some of 

 its leading students, two or three years 

 ago, to found a new periodical entitled 

 Mind: a Quarterly Review of Psychology 

 and Philosophy, to be devoted to the 

 investigation of mental phenomena, 

 especially from the hitherto neglected 

 physiological side. This review has 

 done excellent service. It was a pro- 

 test against the inadequacy of the old 

 method of metaphysical and purely in- 

 trospective study, and represented that 

 class of philosophical thinkers who hold 

 that, in treating of mind, its organic 

 conditions are not to be lost sight of, 

 but that mind and body are to be con- 

 sidered together. 



A further and. very significant step, 

 in the same direction, has now been 



taken by the establishment of another 

 quarterly magazine, under the title of 

 Brain: a Journal of Neurology. 1 The 

 starting-point is here physiological, and 

 the brain and nervous system are studied 

 with reference to their various vital and 

 psychical functions and effects. The 

 editors are all eminent medical men, 

 who have either acquired distinction 

 through large experience in the treat- 

 ment of nervous maladies involving in- 

 tellectual and emotional derangement, 

 or have achieved eminence in the de- 

 partment of experimental physiology 

 of the nervous system. The method 

 is here thoroughly scientific. The 

 brain is not merely something to be 

 recognized, but it is taken as the pri- 



1 Brain : A Journal of Neurology. Edited 

 by J. C. Bucknill, M. D J. Crichton-Browne, 

 M. D., D. Ferrier, M. D., and J. Hughlincrs- 

 Jackson, M. D. 142 pnges quarterly. Price, 

 3s. 6d. New York: Macniillan & Co. 



