196 



NATURE 



[December 27, 1S94 



lege they have neglected — to demand here, by assuming a 

 sound basis of chemical and physical knowledge, the 

 proper sequence of studies. As it is they have produced 

 a little primer that by virtue of its clearness and attrac- 

 tiveness and the prestige of their names, will serve to 

 uphold for a fe«- years longer a fundamentally faulty 

 system of scientific education. 



The evil of a neglect of the rational sequence of studies 

 becomes particularly apparent in the chapters upon theeye 

 and ear. In the former of these an attempt is made to 

 convey all the optical principles involved, in seven lines — 

 '•convex lens" is not even defined^and in the latter comes 

 a series of dogmatic statements about sounds and noises, 

 without a particle of that progressive reasoning process 

 which is the very essence of genuine scientific study. 

 Once the initial concession svas made, however, this kind 

 of thing was an inevitable consequence. In order to 

 explain the science in hand, three or four others have to 

 be compressed to the limits of a paragraph. 



The same unfortunate disposition to begin the wrong 

 way about is apparent in the little book by Mr. Chalmers 

 Mitchell. But in his case there is even less excuse. His 

 book is designed to prepare students for the Conjoint 

 Boards E.xamination, and therein he is an examiner. 

 Since he calls the tune he might have danced as he liked, 

 and he has, we conclude, preferred of his own free will 

 to contravene the common-places of educational science. 

 We find such a proposition as the following, printed in 

 spaced type ; so that the medical student, preparing for 

 examination by Mr. Chalmers Mitchell, who fails to learn 

 it by heart will have only himself to blame for his failure. 

 The earthworm, we are told, 



" has reached the second stage of coelomate develop- 

 ment in that it is very highly segmented, and there is 

 little or no trace of the third stage, the stage of the con- 

 densation of segments." ..." V'ertebrates are highly 

 segmented animals, in which condensation of segments 

 has become an important factor, resulting notably in the 

 formation of a complicated head, and of kidneys formed 

 by the aggregation of many nephridia." 



Now these propositions are illustrated rather than sup- 

 ported by a brief description of the anatomy of the earth- 

 worm, dogfish, and frog, and we find that even in the 

 case of these types the metameric segmentation of the 

 cranial nerves is scarcely alluded to, and the homology 

 of the mandibular arch with the branchial bars is not 

 presented as a probability, but stated as a fact. .Vnd, in 

 brief, .Mr. Chalmers .Mitchell, who is not a crammer, but 

 a teacher, gives the medical student the impression 

 almost in so many words — " cut and dried " and ready to 

 be cast into the oven — that the vertebrate type is merely 

 a concentrated derivative (concertina fashion) of the 

 chxtopod type, advancing this pure, and as he gives it, 

 baseless, speculation, in the face of the absence of any 

 ch.x'topod stage in the embryology or paleontology of the 

 vertebrates, in the face of the lesser metamerism in the 

 vertebral column of more primitive fishes, and in the face 

 of the declared opinion of many prominent anatomists. 

 Hut whether the view he gives is right or wrong is, from 

 our point of view, the smaller issue ; the great and grave 

 objection is the unscientific spirit of the presentation, the 

 narrowness bf the base of anatomical fact upon which 

 this far-rcachmg generalisation is raised. \Vc find this 



NO. 1313. VOL. 51] 



disposition to what is really the old theological trick of 

 dogmatism, again and again in his book, and it is the 

 evident and necessary consequence of an attempt ta 

 touch the far-reaching theories of comparative anatomy 

 without a sufficient preliminary study of individual types. 

 It is odd that we should find another aspect of the same 

 mistake cropping up in one chapter of Mr. Clar'-^'s ex- 

 tremely useful and well-arranged handbook for the 

 beginner in microscopy. It is in almost every way a 

 well-arranged and well-written work, and will be par- 

 ticularly a boon to the amateur to whom experienced 

 advice is inaccessible. But before proceeding to the 

 petrographical instrument, Mr. Clark has attempted a 

 "concise description" of polarised light, which begins — 



"The elasticity of the ether in space is believed to be 

 equal in all directions. The same is true of the ether in 

 non-crystalline substances and in crystalline substances 

 of the cubical system. The particles of ether are con- 

 sequently free to vibrate equally in all directions. In 

 other crystalline substances the elasticity of the ether is 

 modified by the crystalline structure. In some crystals 

 there is one axis or direction about which the molecules 

 are arranged in a uniform manner ; such crystals are 

 said to be uniaxial. In other crystals there are two such 

 axes." 



Now we believe a student who will clearly understand 

 this will be sufhciently advanced not to require it, and 

 that to the raw beginner, this passage, and its context, 

 will be incomprehensible. Were it not for the actual 

 evidence of these books it would seem the most unneces- 

 sary thing in the world to assert that a clear working 

 idea of the theory of polarised light, or the general 

 ideas of chemistry and physics, or a cyclopxdia of the- 

 anatomy of the metazoa, cannot be imparted in half 

 a dozen pages or so of text. If it could, our text- 

 books in these subjects would be unnecessary, for the 

 ultimate aim of all intelligent research and teaching in 

 pure science is broader and simpler general notions, and 

 there can be no need for a volume if a handbill will 

 sutlice. Cannot the scientific writer insist upon the- 

 proper sequence of studies in his preface, and proceed 

 on the assumption that his counsel will be observed .' To- 

 positively encourage students to proceed to subjects for 

 which they have not the necessary grounding, to proffer 

 them snap-shot chapters upon these neglected pre- 

 liminaries, is really, we are persuaded, to place a grave- 

 impediment in their way to genuine knowledge, all the 

 graver because it seems a help, and to place one also in 

 the way of our advance towards more efiicient science- 

 teaching in the future. H. G. Wei.LS. 



OUR BOOK SHELF 



Climbing and Exploration in the Karakoram- Himalayas. 

 By William Martin Conway, .M.A., F.S.A., &c. Con- 

 taining ijcientitic Reports. (London: T. Kisher Unwin, 

 1894.) 

 This supplementary volume contains reports on the 

 scientific results of .Mr. Conway's adventurous journey, 

 with his map of the mountain region between Kakipushi 

 and Golden Throne, through which he travelled. The 

 author supplies a list of measured altiludrs and notes on 

 the map, mentioning the differences from that of the 

 Triyononietrical .Survey of India. Lieut. -Colonel A. C. 

 Durand describes the ethnology and later history of the 



