586 



NATURE 



[January 28, 19 15 



procedure, and the chapter on the composition of 

 enamels, are specially valuable. 



The accounts given, however, of the prepara- 

 tion of the materials are in a few cases of doubtful 

 value, and in the case of the metallurgy of tin 

 even inexact. It is, too, not obvious what useful 

 purpose can be served by the introduction of the 

 graphic formulae of the felspars. 



These are, however, minor defects. The book 

 is a good one, and the appearance of a translation 

 into English has rendered the industry in this 

 country a valuable service. It should be in the 

 hands of everyone connected with enamelling 

 works. W. G. 



NEW BOOKS ON CHEMISTRY. 

 (i) Van Nostmnd's Chemical Annual, 1913. 



Edited by Prof. J. C. Olsen. Pp. xiv + 669. 



(London : Constable and Co., Ltd., 1914.) Price 



125. 6d. net. 

 (2) A Text-book of Chemistry. By W. A. Noyes. 



Pp. XV + 602. (London : G. Bell and Sons, Ltd., 



n.d.) Price 85. 6d. net. 

 {2) The Electrical Conductivity and lonisation 



Constants of Organic Compounds. By Dr. H. 



Scudder. Pp. 568. (London : Constable and 



Co., Ltd., 1914.) Price 12s. 6d. net. 

 (i) " \ /"AN NOSTRAND'S Chemical Annual 

 V for 191 3 " is arranged on much the 

 same lines as the well-known German " Chemiker 

 Kalendar" of Biedermann. It contains a great 

 number of tables of constants and a vast amount 

 of other information useful to chemists. It is, in 

 short, the kind of reference book which no prac- 

 tical chemist can afford to be without; for the 

 amount of time it must save will soon repay him 

 for its rather high price. 



Seeing that the bulk of each annual issue is a 

 mere copy of a former one, it seems as if some- 

 thing could be devised whereby the small amount 

 of new matter and corrections might be published 

 separately without the expense of repurchasing the 

 whole volume. The present issue is embellished 

 with an excellent portrait and a short obituary 

 notice of Prof. Henri Moissan. 



(2) A text-book written for beginners is always 

 difficult to appraise at its true value unless one has 

 some notion of the character and extent of the oral 

 and practical teaching which necessarily accom- 

 pany it. As it stands there is little to find fault 

 with in this volume, either in regard to the ar- 

 rangement of subjects, the descriptive portion, or 

 the facts, yet unless there is a great deal of ampli- 

 fication we have grave doubts if it could be re- 

 commended unreservedly as a satisfactory first 

 text-book. The matter is condensed into short 

 NO. 2^61. VOL. Q4.1 



paragraphs dealing with a great variety of topics. 

 We find, for example, in the first hundred pages 

 or thereabouts, in addition to much experimental 

 information, accounts of the ionic theory, equili- 

 brium, reversible reactions, catalysis, valence, the 

 phase rule, the atomic theory, the van 't Hoff-Le 

 Chatelier law, molecular volumes, etc. Even the 

 "quantum theory" is introduced later in a para- 

 graph of fifteen lines, and we have no hesitation 

 in saying that, in so far as it attempts to convey 

 any information, it is so much wasted space. 



The book is, in short, a midtum in parvo, no 

 doubt excellent as a summary of n.any and divers 

 facts and theories. 



We would ask again, as we have frequently 

 done in reviewing other elementary text-books, 

 whether any object is served by introducing at the 

 beginning definitions and generalisations of the 

 nature of, which the student has as -yet orly vague 

 ideas? Is anything substantial to be gained by 

 stating (p. 5) that matter is anything which has 

 mass, or that matter is anything which requires 

 energy to set it in motion, when, on the next page, 

 energy is defined as anything which may set 

 matter in motion ? 



A great difference is often observed in the atti- 

 tude of students towards physics and chemistry, 

 and the reason probably is that in the one he is 

 taught to reason logically, because he is made to 

 think logically ; in the other he is confronted with 

 phenomena about the nature of which he is rarely 

 encouraged to express his opinion, because he is 

 provided,- often unconsciously, with the explana- 

 tion. The paragraph on elements and compounds 

 (p. 9) affords an illustration. " If the red oxide of 

 mercury is heated in a small tube, metallic mer- 

 cury will distil, whilst a glowing splinter held at 

 the mouth of the tube will burst into flame. The 

 heat causes the decomposition of the oxide of 

 mercury into mercury and a gas which is called 

 oxygen." m 



It is a gratuitous assertion that the phenomenon^ 

 is one of decomposition ; why not say with the old 

 phlogistonists that the red powder has combined 

 with something in the air to form the metal and 

 left the oxygen ? Until the loss of weight is recog- 

 nised this explanation is equally logical ; but theflj 

 of course, if we begin by calling the substance 

 oxide of mercury we merely end by proving what-, 

 we have tacitly assumed at the outset. P 



(3) Dr. Scudder's book is a complete biblio-" 

 graphy of the ionisation constants of all the 

 organic compounds which have appeared from 

 1889 to 1910 inclusive, with corrections down to 

 1913. That the work involved in compiling thes«j.,; 

 tables must have been enormous may be estimated 

 from the author's statement that 78 journals and 



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