108 



SCIENCE. 



[Vol. VII., No. 150 



the psychic unit. The next step takes us still 

 further into the nature of mind by measuring the 

 time necessary for one idea to call up another 

 related to it in any way, — 'association time.' 

 This process is evidently a more complicated one, 

 a higher function, and takes a longer time, about 

 half to three-fourths of a second. Individual dif- 

 ferences are very great here, and we are at the 

 beginning of those mental qualities which in their 

 extremes distinguish the genius from the dullard. 

 Not only the time, but the kind of association, is 

 characteristic of the individual. The direction of 

 one's associations is as good a clew to his character 

 as can readily be gotten. If we limit the subject 

 to one kind of association, for instance, what the 

 logicians call ' subsumation ' (that is, for example, 

 if the word is ' horse,' the associated word must 

 include horse as ' quadruped,' ' animal '), the time is 

 longer by about a tenth of a second than unre- 

 stricted association time. 



Another very curious result which was wrought 

 out in Professor Wundt's laboratory is the peculiar 

 effect of attention, which actually makes you hear 

 or see a thing before the thing is there to be heard 

 or seen. If you are to observe opposite what 

 stroke of a graduated circle an indicator attached 

 to a pendulum is swinging when a bell strikes, 

 then, after the interval between the beginning of 

 the swing and the ringing of the bell has become 

 fixed in your mind, you will anticipate the stroke 

 of the bell, and make it ring a fraction of a second 

 before it really sounds. But a further discussion 

 of this question would carry us too far. It has 

 been shown, that, compared with such motions as 

 light, sound, or electricity, nerve-conduction is 

 slow, and those nerve processes associated with 

 the more complex sensations and perceptions very 

 slow indeed ; that by measuring these times w T e 

 will obtain a graded scale of the complexity of 

 some of the simpler mental processes, and gain a 

 deeper insight into their nature. 



This essay lias been selected because it repre- 

 sents, perhaps, the more strictly original part of 

 the book better than any other. Most of the 

 others are inspired by new points of view, as, for 

 example, the one on language, which takes its 

 basis f rom the observations on the development of 

 language in children and deaf-mutes. 



From the English side comes an attempt to give 

 in a popular form the results of studying the insane 

 and deranged as far as such study bears on cer- 

 tain peculiar historical and psychological facts.' 

 One general topic in which the author is deeply 

 interested is the hallucinations of eminent histori- 

 cal characters. The list of these is so strikingly 



1 Tfir hlol on lln' hid i a : \f ikUck in history and pnycludoyy. 



By vv. w. Ikki.and, M.D. New Y->rk. Putnam, ihho. 



large, if one is willing to take into account very 

 small deviations in mental soundness, that it has 

 led to the thesis (old as Aristotle) that genius and 

 insanity are closely allied. But the cases treated 

 by Dr. Ireland are only those in which this 

 hallucination gave character and motive to the 

 life of the individual. The peculiar mental con- 

 dition of Mohammed, Swedenborg, and Joan of 

 Arc, are graphically and instructively presented : 

 they form a welcome contribution to the psy- 

 chology of greatness. In this connection may be 

 mentioned a w^ork on genius, 1 recently published, 

 which, though it makes no claims to be, and is 

 not, a scientific book, touches with a somewhat 

 literary motive on this topic. The writer has 

 made a strong statement of the vanities of eminent 

 men ; not of men of genius, however, in any 

 proper sense. 



Another peculiar malady which the flesh of the 

 great is heir to, is the ' insanity of power.' The 

 proposition is, that persons in positions in which all 

 their wishes and whims can be put into deeds at 

 once, are liable to become intoxicated with this 

 omnipotence, and to indulge in morbid and cruel 

 practices. The horrible spectacles wmich the reign 

 of the Claudian-Julian family of emperors at 

 Rome, reaching the climax in Nero, presented to 

 the world, shows the terrible force of this disease, 

 and its hereditary nature. The reigns of Ivan the 

 Terrible in Russia, and of Mohammed Toghluk in 

 India, are other examples of the debasing effects 

 of unchecked power, while the hereditary neurosis 

 of the royal family of Spain illustrates the special 

 dangers to which these select families are subject. 



Another line of interest with Dr. Ireland is the 

 study of the relation of the two sides of the body. 

 As the main motor nerves cross from the brain to 

 the opposite side, w T e are right-handed and left- 

 headed. This predominance of the left hemisphere 

 of the brain is an indication that the two hemi- 

 spheres only in part are one, and in part are two. 

 Have we one brain or two brains? is, then, not at 

 all an unnecessary question. The peculiar phe- 

 nomenon of mirror-writing (i.e., of writing from 

 right to left, so that when reflected in a mirror it 

 appears normal), which appears in children and 

 some forms of insanity, has attracted notice to ibis 

 question. The results as yet are not very definite. 

 Other psychological curiosities, such as sympa- 

 thetic insanity, which makes whole families go 

 insane at once, peculiar fixed ideas, and so on, are 

 treated in a popular way. The book will not say 

 much that is new . but gives in a very readable 

 form an interesting account of some of the 

 modern phases of psychological thought. J.J. 



1 Insanity and vanity of genius. By Kate Sanborn. 

 New York, 



