58o 



NA TURE 



L^ )ci»ii>hK 20, 1923 



two lectures are devoted to a discussion concerning 

 the significance of certain features of the electro- 

 cardiogram. 



From a historical poiiii ui view, this little lK)ok is 

 of considerable interest ; but, in a subject so young 

 as electrocardiography, a period of ten years is sufficient 

 to bring about considerable modification in views 

 previously current, and the omission of references to 

 the more recent work cannot fail to detract from the 

 value of hypotheses based on the earlier experiments. 

 One cannot help feeling that the views expressed are 

 those of an advocate rather than a judge. In such 

 small and unimportant details as the nomenclature 

 of the different deflexions of the electrocardiogram, 

 it is somewhat surprising that a pioneer worker in 

 this branch of physiology should be so reluctant to 

 adopt a phraseology which is now almost universally 

 employed. J. C. B. 



A. D. R. 



Organic Preparations. 



(i) An Advanced Laboratory Manual of Organic 

 Chemistry. By Dr. M. Heidelberger. Pp. 103, 

 (New York : The Chemical Catalog Co., Inc., 1923.) 

 2 dollars. 



(2) Organic Syntheses : an Annual Publication of 

 Satisfactory Methods for the Preparation of Organic 

 Chemicals. Edited by J. B. Conant, H. T. Clarke, 

 R. Adams, and 0. Kamm. Vol. 2. Pp. vii + ioo. 

 (New York : J. Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd., 1922.) 75. (>d. net. 



(3) A Method for the Identification of Pure Organic 

 Compounds by a Systematic Analytical Procedure 

 based on Physical Properties and Chemical Reactions. 

 By Prof. S. P. Mulliken. Vol. 4: Containing 

 classified descriptions of about 3700 of the more 

 important compounds belonging to fourteen of 

 the higher orders. Pp. vii + 238. (New York : 

 J. Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1922.) 305. net. 



(4) Cours de chimie organique. Par Prof. F. Swarts. 

 Troisi^me edition, rev^ue et augmentee. Pp. iii + 674. 

 (Bruxelles : M. Lamertin ; Paris : J. Hermann, 

 192 1.) 50 francs. 



(i) A /r ETHODSof preparation in organic chemistr>', 

 IV J. like all other branches of the science, tend 

 to become out-of-date, and probably every teacher has 

 his own list, culled from recent literature, which he 

 gives to those students who have to bridge a gap 

 between " preparations " and " research." Indeed, if 

 properly chosen, supplementary preparations of the 

 kind mentioned lend themselves admirably for the 

 purposes of initial instruction in the methods of 

 NO. 2816, VOL. I 12] 



research, when, as sometimes happens, the rt 

 on which the advanced student is started doi 

 involve the preparation of large quantities rif initial 

 material. 



The book under review contains a numlx*r of pre- 

 parations of this kind which the author has coll 

 after many years of experience of teaching and rest.... ... 



and these he now offers to his fellow-teachers with an 

 apology in his prefatory note for the fact that man\ 

 of the details have lieen taken from his own work 

 and that of Dr. Walter A. Jacobs, of the Rockefeller 

 Institute. Organic chemists will, however, know that 

 it is the first-hand information that counts, and that 

 the author writes of a subject with wluch he is fully 

 competent to deal. 



The book is well printed and easy to read. The 

 printer has evidently experienced difficulty in setting 

 up some of the more complex formula;, and the result 

 is, in some cases, apt to make one dizzy, but, even 

 thus, it is better than the easier and cheaper method 

 of attempting to represent such formulae in a straight 

 line. Dr. Heidelberger has produced a useful littlt 

 book for those teachers of organic chemistry who 

 may wish to give their advanced students some more 

 difficult preparations than those usually to be found 

 in the ordinary laboratory manuals. 



(2) This is the second volume of the series and is 

 well up to the high standard set by the first. Twenty- 

 five preparations are described, and all of them deal 

 with compounds likely to be required in an organic 

 chemical research laborator}-. Each substance is 

 treated under three headings, namely, (i) procedure. 

 (2) notes, and (3) other methods of preparation ; the 

 method of procedure being given in sufficient detail 

 to enable an ordinary advanced student to follow it 

 with ease. The notes are in every case well written 

 and give valuable and essential advice which will be 

 of the greatest assistance to those who have to carry 

 out the preparations. Brief but cogent criticisms are 

 given of other methods of preparation in the sections 

 devoted to this head, and the reasons why such methods 

 have proved unsatisfactory in practice are clearly 

 stated. 



In every case the preparation has been carried out 

 by one of the associated editors and checked by another, 

 and as all four of them are organic chemists of high 

 standing, there is no room for error. If it were possible 

 to make this admirable compilation still more admir- 

 able, it might be done by a freer use of graphic formulje 

 at the heading of the chapters — they take more room, 

 but are well worth it — and by pandering to English 

 laziness by giving where possible the volume of solu- 

 tions as well as the weight. For example, on p. 75, 

 the expression " 400 g. of 28 per cent, ammonium 



