December 30, 1 Sq;] 



NATURE 



197 



gives a brief sketch of the conclusions that may be drawn 

 from a study of the remains recently found by Prof. 

 Petrie between Dallas and Naqada. Towards the end 

 of the sixth dynasty the Libyans, yielding to a migratory 

 1 impulse, overran the western frontier and established 

 themselves in Egypt, leaving a permanent record of their 

 presence in the burying places and remains of villages 

 which extend the whole length of the mountain chain 

 from Siut to Gebelen. Prof. Maspero does not go so far 

 as Prof. Petrie, who would regard the whole of the south 

 of Egypt as having been wrested from the native kings 

 by this "new race"; he does, however, conclude that 

 these Libyan settlers were predominant throughout a 

 considerable area on the left bank of the river, and that 

 their influence was felt for more than a century. The 

 pagination remains the same as that of the two earlier 

 editions of the book. 



The Local Distribution of Electric Power in Work- 

 shops^ S^c. By Ernest Kilburn Scott, A.LE.E. Pp. 

 137 + viii. (London : Biggs and Co.) 



The advantages of electric transmission of power in 

 factories and workshops are not so well known as they 

 might be, or the electric driving of machinery would 

 be more extensively adopted than it is. Wherever 

 electric motors have been made to do duty in machine 

 shops, complete success has been attained, but it is only 

 in late years that engineers and proprietors of factories 

 have learned to make use of electric driving to any great 

 extent. Lately, however, this branch of electrical 

 engineering has been coming to the front, and it promises 

 to develop into the most important branch of electrical 

 work, electric lighting not excepted, 



The information brought together by Mr. Scott will 

 show manufacturers what has been done, and what 

 electric motors are capable of doing. The advantages 

 of electric driving, both economically and commercially, 

 are clearly pointed out, and detailed particulars of power 

 required by various machines are given. The advantages 

 and disadvantages of alternating currents from the point 

 of view of power distribution in factories are discussed, 

 and there are descriptions of the various points of a 

 power installation, with examples of the most recent 

 practice. The book is thus one which should be in the 

 hands of all who are concerned with the applications 

 of electricity to the machines and tools of workshops 

 and factories. 



Memory and its Cultivation. By F. W. Edridge-Green, 

 M.D., F.R.C.S. (International Scientific Series.) Pp. 

 307. (London : Kegan Paul and Co., Ltd., 1897.) 

 Dr. Edridge-Green considers that the human mind 

 is divisible into " ultimate faculties," a list of which he 

 gives. Of these " ultimate faculties " some thirty-seven 

 are assigned to this position with certainty. Dr. Green 

 has no doubt whatever about their fitness to be con- 

 sidered " ultimate faculties," although amongst them are 

 suchqualities as Causality, Alimentiveness, and Inhabitive- 

 ness. Others there are, such as Vitativeness and Human 

 Nature, whose position as ultimate faculties of the human 

 mind is still sub judice. Dr. Green might, we think, have 

 postponed the publication of this book until he had made 

 up his mind about them. Part of the book is devoted to 

 the description of a system of cultivating the memory; 

 but there is the best possible evidence that either Dr. 

 Green does not himself utilise this system, or the system 

 is worthless. He would certainly never have published a 

 work on psychology without acquainting himself with the 

 present state of knowledge upon the subject. Yet he 

 has forgotten the whole of his psychological studies as 

 completely as if they had never existed. If his system 

 were one for cultivating the art of forgetfulness, and 

 were a perfect system, the result could not be more 

 complete. 



NO. 1470, VOL. 57] 



Illusions and Hallucinations. By Edmund Parish. Pp. 

 xiv + 39a (London : Walter Scott, Ltd., 1897.) 



This is a very thorough account of the subject, in fact it 

 is, perhaps, for the' series to which the book belongs, 

 almost too thorough, and the general reader may find 

 some difficulty in getting a clear account of the author's 

 views out of the mass of detail. The conditions of 

 fallacious peiception are fully considered, and the general 

 phenomena are referred to disturbed association. The 

 author gives new definitions of illusion and hallucination, 

 ihe former being supposed to depend on the suppression 

 of certain processes which normally intervene between 

 the immediate sensory change and the perception process, 

 while hallucination is referred to forced association. 

 These definitions have the advantage that they refer both 

 phenomena to a common cause, i.e. to dissociation of 

 centres normally acting together ; but they are open to 

 tlie objection that they are based on purely theoretical 

 and uncertain views, and it would probably be better to 

 retain the old definition depending on the existence or non- 

 existence of an external stimulus while recognising that 

 there is no hard and fast line between the two conditions. 

 There are two interesting chapters on the results of the 

 international census of waking hallucinations. The 

 author brings forward much evidence that the real nature 

 of the " waking state " in most cases was one of abnormal 

 dissociation. He criticises adversely the evidence for 

 telepathy derived from the census, which was regarded as 

 valid by the authors of the English Report. He brings 

 forward from the Report itself evidence against this 

 conclusion, and in regard to the supposed positive 

 evidence, he lays great stress on the importance of simi- 

 larity of association of ideas in the two cases. Among 

 many other interesting points, only one can be mentioned 

 here, viz. the criticism of the view that the negative 

 hallucinations of hypnotism depend on suggested in- 

 attention. The author points out that an object may be 

 made by suggestion to appear smaller and smaller, till it 

 finally disappears. In this case, according to the theory, 

 a phenomenon due to concentration or special direction 

 of attention would be suddenly replaced by one due to 

 lack of attention. 



Transactions of the Rochdale Literary and Scientific 

 Society. Vol. v., 1896-97. Pp. 90 -I- xxii. (Rochdale : 

 James Clegg, 1897.) 

 By publishing the papers in this volume the Council of 

 the Rochdale Literary and Scientific Society brings the 

 work of the Society into prominence, and assists in 

 making the objects of the meetings known to a wider 

 circle. The volume is as interesting as its predecessors, 

 and is a creditable addition to local literature and 

 science. Among the papers contained in the vOi' . 

 is a chatty account of " Men and Manners in Manila," 

 by Dr. A. Jefferson, an elementary description (with 

 figures) of " Egyptian hieroglyphics, picture-writing, 

 and the English alphabet," by Mr. C. Heape, a brief 

 note on some graphite and flint implements found in a 

 neolithic store near Rough Hill, by Mr. W. H. Sutcliffe, 

 and a paper on the geological history of the Cephalopoda, 

 by Mr. Charles Wardingley. 



We see from the report that a number of other papers, 

 not included in the present volume, were read before the 

 Society during the nineteenth session, and several very 

 instructive lectures were delivered. The Society, appears, 

 indeed, to be a centre of light and leading in Rochdale. 



Les Constantes Physico-Chemiques. By D. Sidersky. 



Pp. 207. (Paris : Gauthier-Villars et Fils. Masson 



and C'^ 

 M. Sidersky has already contributed a volume on 

 polarisation and saccharimetry to the Aide-Memoire series 

 in which the present book appears. The constants herein 

 described are dealt with in a similar manner; they 



