466 



NATURE 



[December 9, 1920 



haps, by the growth of micro-organisms. It 

 would be out of place, however, to develop these 

 views here. 



The chapters on the analysis of margarine, 

 etc., contain little to comment upon, except that 

 enough stress is not laid on the iodine value and 

 the hexabromide tests. In the portions dealing 

 with nutritional chemistry the author gives a wel- 

 come review of the work done and of the opinions 

 held by medico-chemists on the so-called "vita- 

 mines," "food hormones," "accessory food 

 factors," "sitacoids," and "advitants." These 

 are " substances " which are supposed to be 

 present in, and give digestibility to, natural fats, 

 and to be absent in prepared or artificial fats. 

 The medico-chemist has thus named them. As 

 Goethe says : — 



Denn eben, wo Begriffe fehlen 



Da stellt ein Wort zur rechtcn Zeit sich eiij. 



Blessed words ! Not one of these so-called sub- 

 stances has been isolated, and no one knows 

 their chemical formulae or characters. Why a 

 "substance" and not a "condition" of a known 

 substance — say, a peroxidised form of some fat? 

 Mr. Clayton seems to see this, and that the whole 

 matter needs consideration from the chemical 

 rather than from the medical point of view, for he 

 states that the term "vitamine" is wrong, as no 

 nitrogen has ever been detected in any of these 

 alleged substances. 



The book contains thirty-five pages of biblio- 

 graphy, and a patents index, and should prove of 

 great assistance to food and emulsion chemists. 



Harry Ingle. 



Our Bookshelf. 



Le Pare National Suisse. Par S. Brunies. Traduit 

 par Samuel Aubert. Pp. 274. (Bale : Benno 

 Schwabe et Cie, 1920.) Price 12 francs. 



The map of the Swiss Topographic Survey, 

 on the scale of i : 50,000, forms part of this 

 attractive publication. The reserve, established 

 by the Federal Government in 1913, occupies a 

 mountainous district trenched by two tributaries of 

 the Inn. The best approach is by Zernez in the 

 Lower Engadine, and the carriage-road to the 

 Miinstertal passes across the park. The author's 

 description, translated frofti the original German, 

 is picturesque and vivid ; but the features that 

 appeal to the visitor trained in scientific pursuits 

 are always kept in view. Special chapters deal 

 with geology and natural history, and the studious 

 revival of the local Latin dialect is recognised by 

 the stress laid on "romand" names. Pronuncia- 

 tions and a list are considerately furnished, and 

 the careful translator informs us that the pro- 

 nunciations given are those used in at least one 

 village — that of Sinuos-chel. Great praise 

 NO. 2667, VOL. 106I 



must be given to the illustrations. Apart 

 from the four exquisite photogravures of 

 the scenery of the park, Mr. H. Pfendsack of 

 Pontarlier has supplied vigorous line-drawings of 

 animals and plants, in every case connecting the 

 subject with its stern environment. Compare, for 

 instance, his Pinus monlana (p. 149), recumbent 

 but undefeated, clutching at the rock, with the 

 climbing birds enjoying themselves as alpinistes 

 on p. 217. He represents with equal insight the 

 family life of the ibex, which it is proposed to 

 restore to its former haunts, and the prolific 

 poppy growing from a heap of stones. The author 

 has well represented the history of the Alpine over- 

 folds by successive sections. It is a pleasure to 

 possess his book. G. A. J. C. 



(i) Easy Lessons in Einstein: A Discussion of the 

 More Intelligible Features of the Theory of 

 Relativity. By Dr. Edwin E. Slosson. With 

 an article by Albert Einstein and a bibliography. 

 Pp. vii-f 128. (London : George Routledge an.l 

 Sons, Ltd. ; New York : Harcourt, Brace, and 

 Howe, 1920.) Price 55. net. 



(2) From Newton to Einstein : Changing Concep- 

 tions of the Universe. By Dr. Benjamin Harrow. 

 Pp- 95- (London: Constable and Co., Ltd., 

 1920.) Price 2S. 6d. 



(3) Die Einsieinsclie Relativitdtstheorie. By Prof. 

 U. Kopff. Pp. 24. (Leipzig : Greszner und 

 Schramm, 1920.) Price 1.50 marks. 



(i) Dr. Slosson gives us in his book a breezy 

 account of what he calls the more intelligible 

 features of the theory of relativity with popular 

 illustrations of distorting mirrors, references to 

 Mr. H. G. Wells's "Time Machine" and other 

 scientific romances, diagrams purporting to por- 

 tray a four-dimensional cube, and general good- 

 humour — a book with which the absolute" layman 

 may amuse himself for a few hours. 



(2) Dr. Barrow gives a more serious, but equally 

 readable, summary of the development of physical 

 science from the mechanical period of the eight- 

 eenth century through the electrical theories of 

 the nineteenth to the present day. Here also th»; 

 layman will find profitable reading. 



(3) The little pamphlet by Prof. Kopff is a re- 

 print of a lecture on the relativity theory to the 

 Natur-historisch-Medizinischen Verein at Heidel- 

 berg in June, 1920. 



Tech7ncal Handbook of OUs, Fats, and Waxes. 

 By P. J. Fryer and F. E. Weston. Vol. i., 

 Chemical and General. Third edition. (The 

 Cambridge Technical Series.) Pp. xii-f28o-)- 

 xxxvi plates. (Cambridge : At the University 

 Press, 1920.) Price 15^. net. 

 The changes occurring in the industrial situation 

 have caused the authors to add a certain amount 

 of matter, and to make a number of alterations 

 in the text of the first edition, which was reviewed 

 in Nature of January 17, 1918. Another addi- 

 tion has been made in the form of analytical data 

 inserted in the text, and a number of footnotes, 

 chiefly giving references to original papers, are 

 now included. 



