Ji'LY 4, 1902.] 



SCIENCE. 



25 



training, and of a proper investigative tem- 

 perament, further invalidate and confuse the 

 records of what is supposed to have been ob- 

 served " (p. 103). 



The chapter on 'The Psychology of Spir- 

 itualism' is a good tonic for any one who may 

 feel himself weakening in his opposition to 

 the spiritistic hypothesis of certain trance and 

 trick phenomena. The psychological notions 

 which lead to the belief, as well as the diffi- 

 culty of obtaining reliable evidence in its 

 favor, are well told in this and the preceding 

 essay on the 'Psychology of Deception.' The 

 fact that a witness is a 'scientist' does not 

 free him. from the usual fallacies of the 

 senses and of false inference; the testimony 

 of such persons often breaks down just at the 

 vital point; witness the celebrated quartette of 

 Zollner, Peehner, Scheibner and Weber, who 

 were so unmercifully hoodwinked by the char- 

 latan Slade. 



This trend toward the occult, as expressed 

 in the forms mentioned, as well as in theos- 

 ophy and ' Christian science,' is due to the im- 

 pulse always present in the race to look at the 

 facts of nature in an intensely personal way. 

 Other forms of this same attitude toward ex- 

 perience are found in ancient divination, in 

 astrology, in the magic and medicine-man 

 practices of savage life. To view the facts in 

 their historical and anthropological perspec- 

 tive is an excellent check on one-sidedness 

 here and elsewhere. With this especial aim 

 Tve have two excellent studies, one of which 

 traces the history of hypnotism through the 

 vagaries of animal magnetism and mesmerism 

 tintil the kernel of truth becomes fairly di- 

 vested of its mystical wrappings, through the 

 work of Braid; the other, with the title of 

 ' The Natural History of Analogy,' shows the 

 development of the belief that a person may 

 be influenced by performing some act upon 

 an object closely associated with him — his 

 form in wax, his footprint, his sword, his 

 name, and so on. 



But not alone in such perspective would 

 the author find the best antidote to the perni- 

 cious tendencies toward the occult, but also 

 in a wholesoiue interest in the genuine and 

 profitable problems of nature and of life. A 



considerable portion of the book is given to 

 a study of certain mental phenomena which 

 are not only important in themselves, but have 

 a direct bearing on the problems discussed in 

 the papers mentioned above. The readiness 

 of the mind to supplement and modify its 

 sense-impressions, so as to bring them into ac- 

 cord with its own prepossessions is shown by 

 a number of simple illusions. But not alone 

 is the power of observation thus afiiected by 

 one's mental attitude, but the power of action 

 is influenced as well. Numerous tracings of 

 hand-movements by means of Professor Jas- 

 trow's well-known ' automatograph ' are intro- 

 duced to show the involuntary effect of differ- 

 ent mental states upon the motor apparatus — ■ 

 interesting and suggestive in connection with 

 ' mind-reading,' ' telepathy ' and the like. 

 On a larger scale a capital instance of the 

 power of suggestion and social 'atmosphere' 

 is given from certain experiences in the Gov- 

 ernment Census Office in 1890. The tabulat- 

 ing machines, when first introduced, caused 

 enormous wear and tear upon the clerks who 

 attempted to master the complicated system of 

 symbols. But when once a considerable body 

 of capable workers with these machines (and 

 thus a more favorable social milieu) had 

 become established, raw clerks could now be 

 put among them, and in a few days without 

 any appreciable nervous strain attained a 

 speed and proficiency which the pioneer clerks 

 had acquired only with difficulty after weeks. 

 The volume closes with a study of the dreams 

 of the blind, in which the author brings out 

 the existence of a critical period at the age of 

 from five to seven years. If blindness occurs 

 before this, the faculty of visiial dreaming is 

 gradually lost; while the occurrence of blind- 

 ness after the critical period has no serious 

 effect upon the visual dream-life. This fact, 

 it turns out, had already been discovered by 

 Heermann as early as 1838; but Jastrow's 

 rediscovery was quite independent. There is 

 included in this chapter an account by Helen 

 Keller of her dreams, told with the charm that 

 always marks her writing. 



It is evident that the spirit and matter of 

 the volume seem to the present writer com- 

 mendable. Beneath an easy and pliant style. 



