58o 



NATURE 



[June 29, 191 1 



holic fermentation, probably the aldehyde-group par- 

 ticipates in the formation of the ester-acid. Dr. 

 Harden remarks (p. 46), 



" the identity of the products from glucose, mannose, 

 and fructose may be explained by regarding the acid 

 as a derivative of the enolic form common to these 

 three sugars, or by supposing that portions of two 

 sugar molecules may be concerned in its production." 

 The "equation of alcoholic fermentation," 



2C,H,.0, + 2PO,HR,= 



2CO, + 2C,H,0 + 2H,0 +C,H„0,(PO.R,)„ 



whilst recording the experimental facts, scarcely 

 affords an explanation of the formation of alcohol, as 

 it is not obvious why, when one of two glucose mole- 

 cules forms hexose-phosphate, the other should yield 

 carbon dioxide and ethyl alcohol. Perhaps the part of 

 the above quotation which the reviewer has put in 

 italics furnishes a clue. 



Chapter iv., dealing with Harden and Younj^'s dis- 

 covery of the coenzyme of yeast-juice and its remark- 

 able properties, is of considerable interest, and the pos- 

 sibility of this containing the phosphate group referred 

 to, though it is admitted that experiments have so far 

 yielded only nej^rative results. The next chapter is 

 devoted to the action of inhibitinj:^ and accelerating 

 afjents on the enzymes of yeast-juice, whilst in 

 chapter vi. the by-products of alcoholic fermentation 

 are dealt with. The results of F. Ehrlich's brilliant 

 work on the production of higher alcohols are clearly 

 expounded, and production of aldehydes and glycerol 

 referred to. It is a matter of interest that only living 

 yeast appears to be capable of producing alcohols from 

 the ami no-acids, and even then only does so in pre- 

 sence of fermentable sugar. The discovery of zymase 

 has furthered the solution of the fermentation problem, 

 but the stability of the amino-acids in the absence of 

 the livinjif orpanism, and the superiority of yeast itself 

 over preparations of its enzymes in effecting the con- 

 version of hexoses into alcohol and carbon dioxide 

 need further explanation. 



The chemical chang-es involved in fermentation are 

 dealt with in chapter vii., and the various explana- 

 tions put forward at different times are recorded; 

 the reader cannot fail to be struck with the small 

 measure of success which has so far attended these 

 efforts. 



Chapter viii., on the "Mechanism of Fermenta- 

 tion," is rather condensed in comparison with the rest 

 of the work ; here, however, one departs somewhat 

 from the biochemical aspect of the problem which 

 has been treated by Dr. Harden in so successful a 

 manner. J. T. H. 



A CRITIC IN GEOLOGY. 



L'Evolution des Theories gdologiques. By Prof. S. 

 Meunier. Pp. 366. (Paris: F. Alcan, 191 1.) Price 

 3.50 francs. 



THIS is one of the most useful works that Prof. 

 Stanislas Meunier has given to his g-eological 

 colleagues, and at the same time it will be appreciated 

 by the general reader. The latter, however, must be 

 constantly on his guard, lest he cry out, "A hit, a 

 very palpable hit," every time that Prof. Meunier tilts 

 NO. 2174, VOL. 86] 



against the theories of to-day. In an introduction 

 intended to show the inexactitude of the works of 

 nature when compared with the demands of mathe- 

 matics, the author seems to include in the same order 

 of things the forms of basalt columns and those of 

 crystallised minerals; he rightly points out the irregu- 

 larity of the former, but says of man (p. 12), 



" k la place des formes toujours vari(''es des objets 

 naturels, il a inventd? les formes gdom^triques . . . 

 tetraedre, cube, rhomboedre . . . auxquels il rapporte 

 les objets v^ritables." 



Prof. Meunier doubts the conclusions of the chemist 

 when he remarks, " De meme, k la place des com- 

 poses naturels, il k invent^ des composes d^finis; 

 oxydes, acides, sels," &c. .\11 this is harmless Meunier- 

 ism to the trained geologist, and will be taken in good 

 part, like the author's rejection of the reality of the 

 Ice age; and it is undoubtedly good for us to have 

 the erroneous conclusions arrived at in the past by the 

 " unanimity of geologists " pointed out as a warning 

 for our later age. 



The history of geological thought exhibits to us a 

 science more cumbered by theory in its earlier stages 

 than it is at the present day, and Prof. Meunier does 

 well to begin with cosmogony, tracing the study from 

 Moses to Sir George Darwin. The form of the earth 

 and the nature of its interior are then discussed, with 

 references in the main to French authors. But in 

 succeeding chapters the literature of the world is freely 

 drawn on, and is often criticised as freely. The 

 chapter on mountain building is of special interest, 

 though a more regular chronological arrangement 

 would have aided the reader. The author hails with 

 complete approval the views of Suess on horsts, and 

 of Schardt and Termier on horizontal overfolds, and 

 justice is done (p. 99) to Reyer's theory of gravita- 

 tional sliding. 



The chapter on earthquakes is still more injured by 

 lack of systematic arrangement, and cannot be re- 

 garded as complete. In that on metamorphic theories 

 we should have liked to find the names of Scrope and 

 Darwin, both of whom had such clear views on 

 foliated rocks; but Hutton, Lossen, Lehmann, and 

 Michel L^vy are similarly passed over, and the chapter 

 is a brief essay rather than a history. Rivers and 

 glaciers are more adequately dealt with. The chapter 

 on the latter concludes (p. 282) with the following 

 amazing statement as to the striated pebbles found in 

 boulder clays : — 



" Or il est maintenant d^montr^ que les stries . . . 

 ne sont aucunement d'origine glaciaire et qu'elles 

 d(^rivent entierement du phenomene d'erosion realist 

 dans la masse des eboulis par Tinfiltration des eaux 

 de pluie." 



Has Prof. Meunier ever consulted an agriculturist as 

 to the penetration of boulder-clay by rain, or has he 

 seen the scratched blocks in a modern glacial deposit, 

 newly revealed from Arctic ice? He continues the 

 discussion when dealing with "theories sedimen- 

 taires," and asserts firmly (p. 301) that " pratiquement 

 les glaciers ne strient pas de galets." French tourist 

 steamers now penetrate the fjords of Spitsbergen, and 

 Prof. Meunier should certainly ask one of these to land 



