March 7, 1901] 



NA TURE 



439 



The bearing of " metageometry " upon Kant's doctrine 

 of space is still sub judice. It is open to the Kantian to 

 maintain either that " bent" spaces fall within Euclidean 

 space, multidimensional spaces being an hallucination 

 •due to abuse of algebraic symbolism, or, with Mr. 

 Bertrand Russell, that if Euclidean space is experiential, 

 yet some " form of externality " is a /r/(?r/. Dr. Scheler 

 is, however, throughout the discussion suggestive, if 

 inconclusive. 



Less satisfactory is his treatment of causation. The 

 statement that the conception of uniformity is foreign to 

 the Greek period is absurd. That the period of Roman 

 •decay was one of lawless happenings is not true in the 

 sense of p. 73, and Dr. Scheler does not save himself "by 

 after qualification, in view of the exaggerated position of 

 p. 69, that the causal category which makes natural 

 science possible as a science of experience would make 

 historical science as a science of experience impossible. 

 The treatment of time and the self is relatively slight. 



The inadequacy of the psychological method is to be 

 found in its equivocal use of the term "facts of conscious- 

 ness." Either it is Protagorean and anarchical, and the 

 objects of all sciences and nesciences are on a dead level 

 of "psychical existence," or there are realities which 

 transcend this accommodating rubric. Idealism is prone 

 to the epistemological fallacy, as positivism is prone to 

 the phenomenalist fallacy. 



If, however, neither transcendentalism with its reduc- 

 tion, nor psychology with its grip on something real- 

 even falsities— can satisfy us, we must, in default of other 

 probable courses, cast about for some syncretist formula 

 uniting the truths and discarding the defects of both. 

 Dr. Scheler declines Sigwart's irenicon, because of the 

 primacy it involves of the moral and volitional element 

 in life. Surely this is not ineradicable from Sigwart's 

 formula? Rejecting this, and the solutions of which it is 

 the type, he falls back upon the endeavour of his teacher, 

 Eucken, to make jettison of all in both methods that 

 offends the time-spirit, and to fashion what is left, with 

 the aid of something which both had left out, into a non- 

 absolutist, non-sceptical scheme, hereafter to be more 

 fully developed. H. W. B. 



OUR BOOK SHELF. 



First Stage Botany, as Illustrated by Flowering Plants. 

 By Alfred J. Ewart, D.Sc, Ph.D., F.L.S. Pp. viii -F 

 252. (London : W. B. Clive and Co., no date). 

 The author sets forth in the preface that his primary 

 object in writing this book was that of satisfying the re- 

 quirements of students preparing for the elementary stage 

 of the Science and Art Examinations. A glance through 

 its pages suffices to prove that this end is everywhere 

 kept to the fore. Even the figures, which are very 

 numerous, are labelled all over in large type so as to 

 enable the student, with the minimum expenditure of time 

 and trouble, to get up the maximum amount of facts. In 

 the text the treatmerit is on analogous lines, and probably 

 the student possessed of a good memory might, with this 

 book as his mentor, succeed in passing a fair examina- 

 tion. Beyond this we have failed to discover why the 

 book was written ; and when its author goes on to state 

 that it is also intended to serve as an "efficient intro- 

 duction to Botany," we simply cannot agree with him. 

 The character of the book is too dogmatic, and too little 

 is left to the student. Indeed, a sentence contained in 



NO. 1636, VOL. 63] 



the preface, advising the student to obtain specimens and 

 " verify upon them the statements made in the text," 

 gives the key to the entire book. Not merely verification, 

 but the fostering of a spirit of inquiry ought to be the 

 chief aim of a teacher, and it is this aspect of the matter 

 which we miss in the volume before us. In the para- 

 graph on geotropism (p. 211) this phenomenon is defined 

 as the " tendency of the radicle or main root to grow 

 towards the centre of the earth " ; a very inadequate 

 definition both from the point of view of fact and theory, 

 and one of little or no scientific value to the student. 



Some subjects, e.g. obdiplostemony, are introduced 

 which would have been better omitted. Unless fully dis- 

 cussed they are of no value educationally, and the space 

 they occupy would be better taken up by a more extended 

 treatment of the more elementary matters. Although, in 

 a general way, the book much resembles others of its 

 class, save, perhaps, in the compression of an unusually 

 large number of facts into its pages, it is but right to add 

 that actual errors are remarkably scarce. 



The Principles of Magnetism and Electricity. An 

 Elementary Text-book. By P. L. Gray, B.Sc. Pp. 

 xvi 4- 235. (London : Methuen and Co., 1901.) 

 Price 3J-. bd. 

 The number of elementary text-books on magnetism 

 and electricity probably exceeds that of text-books 

 on any other subject. One would, therefore, naturally 

 expect that anybody attempting to add to their number 

 would do so with a due sense of responsibility, and en- 

 deavour to produce a book which might be regarded as 

 surpassing those already in existence either in accuracy 

 of exposition or in freshness of treatment. A careful 

 perusal of the book before us has forced us to the con- 

 clusion that the author is destitute of all sense of re- 

 sponsibility, and not afraid to scatter error broadcast with 

 a light heart. Seldom has it been our lot to come across 

 an elementary text-book so full of glaring errors so boldly 

 stated. On p. 18 the author describes a vibrational method 

 of comparing the moments of two magnets in which the 

 moments of inertia of the magnets are not even referred 

 to ! On p. 15 we have the startling assertion that in the 

 case of diamagnetic bodies "the induced magnetisation is 

 at right angles to the field " (the italics are the author's !). 

 Could there be a greater confusion of ideas than that ex- 

 hibited by the following sentence? (p. 151): "Apcle of 

 strength m will have 47r;« lines of force proceeding from 

 it, so that, if a transverse narrow cut be made across a 

 magnet which has a- lines per sq. cm. in any normal 

 cross-section, the field in the narrow slit H will be equal 

 to 4ir(r." The author measures magnetic force in dyneSy 

 and difference of potential in ergs. On p. 162, in con- 

 nection with the induction coil, we read : " Trowbridge 

 has recently obtained sparks nearly seven feet in length, 

 obtaining anE.M.F. of 3,000,006 volts, the primary cur- 

 rent being supplied Jroin a battery of 10,000 storage 

 cells" (the italics are ours). Is the author serious, or 

 does he intend playing a practical joke on his reader, by 

 suggesting that any sane person would use 10,000 storage 

 cells for supplying the primary of an induction coil ? 

 Had he taken the trouble to refer to Prof Trowbridge's 

 papers, the author would have found that the arrange- 

 ment used for obtaining the 3 x 10** volts had nothing 

 whatever to do with an induction coil. On p. 163 

 we have the sentence : "The total value of the mag- 

 netic force within a circuit is known as the magnetic 

 flux through the circuit." Now, what does the author 

 mean by " the total value of the magnetic force within a 

 circuit"? When touching on technical matters, the 

 author does not scruple to make various erroneous state- 

 ments with an airy assumption of superior knowledge. 

 " Theoretically," we are told on p. 166, "every dynamo 

 could be used as a motor and every motor as a dynamo. 

 In practice, however, this power of reversibility is not 

 used." Again, on p. 170, we read : "Owing to the self- 



