May 31, 1917] 



NATURE 



26 



thermodynamic significance of the mass-action 

 equilibrium constant, Helmholtz's method of- cal- 

 culating the E.M.F. of a cell, the meaning of 

 thermodynamic probability in relation to entropy, 

 the laws of radiation, and many other problems, 

 by no means simple in themselves, are here 

 treated in an exceptionally clear and convincing 

 manner. Prof. Sackur's book, regarded as a 

 whole, is a demonstration of the truth of the 

 words with which the introduction commences : 

 " Everyone will admit that a thorough understand- 

 ing of physical chemistry, and of the success of 

 its applications in science and in technology, can 

 only be obtained on the basis of thermodynamics." 

 It only remains to add that Dr. Gibson's trans- 

 lation is thoroughlv satisf actor}'. 



W. C. McC. Lewis. 



OUR BOOKSHELF. 



The Borderlands of Science. By Dr. A. T. 

 Schofield. Pp. viii — 255. (London : Cassell 

 and Co., Ltd., 1917.) Price 65. net. 

 Dr. Schofield tells us in the preface that his 

 object in writing this book is "to present to the 

 reader an entirely new outlook on the subject 

 with which it deals. The word ' borderland ' 

 has hitherto been practically confined to a study 

 of psychic phenomena ; but here the meaning is 

 so extended as to cover all that is obscure and 

 unproved in any science. ' ' The world of con- 

 crete and abstract things is pictured as a huge 

 disc, in the centre of which is God, " the first 

 great cause (though Himself uncaused), dwelling 

 in perfect light " (p. 3); and round the edge of 

 the disc stand "the scientists" in a crowded 

 circle studying the disc by feelers which each 

 mind possesses and "by the light of their own 

 reasoning powers " (p. 4). There are patches of 

 the disc only half illuminated by either the 

 human light or the Divine light, and these 

 patches form the "twilight " regions — the border- 

 lands of science (p. 6) ; and also there are 

 patches "which we should know and need to 

 know, but which science now clearly sees cannot 

 be penetrated by its lights " (p. 7). "The goal 

 of all human knowledge ... is in touch with 

 the Light itself, although to scientists at the 

 circumference, who use only their own lights, it 

 may appear to be impenetrable darkness" (p. 4). 

 The Central Unity is also the God of revelation 

 (p. 40) ; "as we leave the clear though limited 

 light of science we become conscious of a vague 

 premonition or prescience of the spirit world " 

 (p. 63), and "there are some few districts of 

 thought which are illumed neither by science nor 

 by religion " (p. 62). ♦ 



One would like to know how Dr. Schofield 

 knows all this about the Central Unity. There 

 seem to be some sensible and tolerant views on 

 the borderlands of psychical science, and it is 

 mostly the fundamental parts that seem self- 

 contradictory. But there are also somewhat con- 

 tradictory statements about the functions of 

 science and philosophy (p. 10 and p. 12) and 

 what makes up "mathematics" (p. 240 and 

 NO. 2483, VOL. 99] 



p. 246). We read on pp. 33-34: "According to 



Myers, Socrates originated the idea of material 



sciences ; but Swedenborg first attempted to 



introduce a science of the unseen, and his most 



illustrious follower in -this particular direction has 



been Sir William Crookes. " 4> 



The Pruning-Manual. Being the Eighteenth 



Edition, Revised and Reset, of the Pruning- 



Book, which was first Published in 1898. By 



L. H. Bailey. Pp. xiii + 407. (New York: 



The Macmillan Co. ; London : Macmillan and 



Co., Ltd., 1916.) Price 85. 6d. net. 



This book deals with an important side of the 



care of fruit trees. The author considers that 



"the habit of growth, mode of flowering and 



fruit-bearing, and response to manipulation " may 



be grouped under the heading of pruning, and 



this wide view of the subject gives a special value 



and interest to the book. 



In the earlier chapters the descriptions of the 

 growth and branching of the more important 

 fruit trees are remarkably clear, and should prove 

 useful not only to fruit-growers, but also to 

 teachers of botany and Nature-study. The 

 later chapters deal with the general principles 

 of pruning, and give directions for the treatment 

 of the .various fruit trees and ornamental shrubs 

 grown in America. Prof. Bailey lays great 

 stress on the necessity for the continuous good 

 care of orchards as regards both pruning and 

 tillage. 



An interesting chapter on the care of street 

 trees may be mentioned ; instructions are given 

 for the repairing and preservation of old trees 

 which, on account of their position or association, 

 may be specially valuable. 



This manual is intended by the author to bring 

 together the results of long experience in pruning 

 "as handed down from gardener to gardener, 

 fruit-grower to fruit-grower, and as recorded in 

 manv books." As early as the latter half of the 

 sixteenth century the subject was dealt with by 

 Heresbach in " Foure Bookes of Husbandrie " 

 (1586), and also by Mascall (1575). The 

 numerous references in this book, however, are 

 chiefly to works pubUshed in the last twenty 

 vears, and especially to the reports of the valuable 

 experimental trials which have been carried out 

 at Woburn, at Wildpark (Germany), and in Utah, 

 California, and Missouri. It is unfortunate that 

 the author has not added a short bibliography, 

 as the references are scattered in the text or in 

 footnotes, and in one or two cases no date is 

 given. H. A. 



The Aviator and the Weather Bureau. By Dr. 

 Ford A. Carpenter. Second edition. Pp. 54. 

 (San Diego: Chamber of Commerce, 1917.) 

 This small book gives a brief history of American 

 aviation as it is associated with southern Cali- 

 fornia, and contains a considerable number of 

 interesting illustrations. It points out the 

 advantage of the climate of California for avia- 

 tion studies, and gives in chap. iii. an account 

 of an ascent made by the author over the city of 

 San Diego. 



