578 



SCIENCE. 



[N. S. Vol. IV. No. 94. 



fear ; its bodily effects and expression ; its rela- 

 tion to health (the weak are more subject), to 

 intellectual development (no relation), and to 

 development of imagination (active imagina- 

 tions are more subject) ; the proportion of chil- 

 dren subject to it (all, in some degree ; excep- 

 tionally, about 10 per cent, of boys and 30 per 

 cent, of girls, by rough estimate) ; the influence 

 of contagion, over-excited imagination, ill-treat- 

 ment, in its production ; and the best method 

 of cure. As to cure, the method must vary; 

 in some cases the best means is attention to the 

 state of health ; in others, the naturally cura- 

 tive effect of time ; in others, moral treatment. 

 For the latter the most important precepts are : 

 Avoid corporal punishment, threats and mock- 

 ery ; suppress the circumstances which produce 

 fear ; guard against over-excitement of imagina- 

 tion ; give the child self-confidence ; train him 

 gradually and progressively in acts of courage. 

 C. General Reviews. 



(1) Dr. Azotjlay : Recent theories, histological 

 and mechanical, of the functioning of the central 

 nervous system. (Pp. 255-294.) A resume of 

 the present state of knowledge in regard to the 

 structure of the nervous system, followed by a 

 detailed exposition and criticism of the theories 

 as to its mechanism recently advanced by 

 Riickardt, Lepine, Duval and Cajal. 



(2) V. Henri : The sense of locality of the 

 skin. (Pp. 295-362.) Reviews the literature of 

 the subject and the results of experiment, from 

 the time of Weber (1834) to the present; and 

 gives a bibliography of 156 titles. 



(3) J. Passy : Olfactory sensations. (Pp. 363- 

 410.) An account of the as yet very incomplete 

 researches in this field. 



(4) BiNET and Henri : Individual Psychology. 

 (Pp. 411-465.) Insists on substituting for the 

 a priori classifications of characters which have 

 heretofore prevailed, deductions from actual 

 measurements of individual differences in fun- 

 damental mental processes. Gives a brief his- 

 toric summary of the questions thus far studied 

 in individual psychology; and maintains that 

 investigations in this field have confined them- 

 selves largely to sensations, whose individual 

 differences are slight and insignificant compared 

 with those of the higher mental processes. A 

 series of more fundamental tests is recommended 



which include : memory — for geometrical forms, 

 for paragraphs, for music, colors, series of figures 

 nature of mental images ; imagination, passive 

 and constructive ; attention, its duration, ex- 

 tent, concentration ; power of understanding, 

 observing, defining and distinguishing ; sugges- 

 tibility ; aesthetic feeling ; moral feeling ; mus- 

 cular force and force of will ; motor ability and 

 accuracy of estimates made by the eye. Ex- 

 plicit directions are given for each of these. 



(5) V. Henri: The calculation of probabilities 

 in psychology. An able paper, developing for- 

 mulae for the calculation of such probabilities 

 as have importance for psychology : determina- 

 tion of averages, of the possibility, nature and 

 laws of variations from the average, of probable 

 errors, of the existence of causes other than 

 pure chance in certain results, etc. The author 

 criticises current interpretations of veridical 

 death-coincidences, and of * thought-reading ' 

 experiments, and more at length the methods 

 of calculation used for many psychological in- 

 vestigations. E. B. Delabarre. 



Brown University. 



The Gas and Oil Engine : By Dugald Clerk. 

 Sixth Edition, revised and enlarged. New 

 York, John Wiley & Sons. 1896. 

 This important work was first issued ten 

 years ago by its author, who was at once recog- 

 nized as an authority on the subject chosen for 

 his study. Mr. Clerk is an engineer of large 

 experience in this field, an inventor of great 

 talent, and a builder of steam and gas-engines 

 of reputation and success. He has, in this 

 work, given to his profession and to .the public 

 an admirable account, historical, scientific and 

 practical, of this remarkable and increasingly 

 important class of heat-engines which is at 

 once one of the most complete, accurate and 

 detailed yet published. It has found a large 

 sale in this country as well as in Europe, and 

 constitutes one of the most generally satisfac- 

 tory and useful of all existing treatises on the 

 subject in any language. While not as com- 

 plete in its collection of working drawings for 

 use in the engine-builder's establishment as is 

 the work of Mon. Richard, and while in some 

 respects less elaborate in some portions of its 

 purely scientific discussion of the theory of the 



