r79 
NATURE 
[JUNE 9, 1923 

reader. It would certainly be desirable for such an 
intricate notation to be simplified. 
The book ends with eighty pages of tables giving 
the numerical values of certain actuarial functions 
according to various laws of mortality. 
W. E. H. B. 

Our Bookshelf. 
Nutrition de la plante:; utilisation des substances 
ternaires. Par Prof. M. Molliard. (Encyclopédie 
Scientifique: Bibliotheque de Physiologie et de 
Pathologie végétales.) Pp. 306. (Paris: Gaston 
Doin, 1923.) 15-40 francs. 
In this volume the author has aimed at presenting, as a 
concrete whole, much of the scattered information with 
regard to the ultimate utilisation of the non-nitrogenous 
compounds produced by plants in the course of their 
metabolism. Dealing in the first place with the diges- 
tion and migration of reserve materials, chiefly sugars, 
starches, and oils, attention is directed to the function 
of the various diastases, and to the mechanism of dia- 
static action. It is concluded that diastatic reactions 
represent merely a particular case of the ordinary 
catalytic phenomena, the apparent discrepancies being 
explained by the colloidal nature of the catalyser and 
the physical properties of the products resulting from 
the reaction. Respiration, with its attendant pheno- 
mena of oxidation, is discussed in some detail with 
special reference to the function and mode of action of 
the oxydases. Other oxidation processes are exempli- 
fied by fermentations induced by some of the lower 
fungi and bacteria, as in the production of acetic acid 
by various bacteria and oxalic and citric acids by 
certain Mucedinee. The final chapters deal with 
fermentations which do not result in the fixation of 
oxygen, particularly alcoholic fermentation and intra- 
molecular respiration, together with the production of 
such substances as lactic and butyric acid by bacteria 
in the presence of the appropriate sugars. The book 
thus provides a useful résumé of the aspect of plant 
nutrition with which it deals. 
Matter, Life, Mind, and God: Five Lectures on Con- 
temporary Tendencies of Thought. By Prof. R. F. 
Alfred Hoernlé. Pp. xiii+215. (London: Methuen 
and Co., Ltd., 1923.) 6s. net. 
Tue five lectures in ‘‘ Matter, Life, Mind, and God” 
present us with the main tendencies of philosophical 
thought in respect of the great problems of philosophy 
indicated by the title. Prof. Hoernlé’s aim is to 
consider these questions synoptically, and he shows 
admirably how no one abstract point of view of a single 
science can be considered as having exhausted reality. 
His treatment of the relations of science, religion, and 
philosophy, of the tendency away from a materialistic 
outlook (he calls this chapter “The Revolt against 
‘Matter’ ”’), of the order of Nature, of the nature 
and function of mind, and of religion and the 
meaning of “God,” is fresh and stimulating. The 
book suffers from a certain diffuseness, which is 
perhaps inevitable considering the wide range of the 
tendencies of thought which are considered in it ; 
NO. 2797, VOL. III] 


and this fact is apt to mask the synoptic conclusions 
which the reader is expected to draw from it. There 
are excellent bibliographies appended to each chapter, 
with notes as to the relevancy of works cited to various 
positions stated in the text. 
Memories of Travel. By Viscount Bryce. Pp. xiii 
+300. (London: Macmillan and Co., Ltd., 1923.) 
12s. 6d. net. 
From many notes of travel, written in various parts 
of the world, these sketches have been selected for 
publication. They cover a wide range, Iceland, 
Poland, the Alps, Palestine, Siberia, North America, 
and the islands of the Pacific. Slight as most of the 
chapters are, they were well worth publication. Lord 
Bryce was a careful observer of Nature and had 
interests so wide and a taste in scenery so catholic 
that every land seems vivid before the reader’s eye. 
His charm of style and ease of description make one 
overlook the occasional weakness in his geological 
explanations. The chapter on Iceland, written in 
1872, gives a description of Icelandic scenery and 
peasant life that could scarcely be improved and yet 
it runs to less than fifty pages. Vivid pictures of 
Tahiti, of travel in the Altai mountains, or climbing in 
Europe are equally fresh and interesting. Even his 
“catalogue of the scenery of North America ” is most 
attractive, although the whole continent is embraced 
in some two dozen pages. It is to be hoped that 
further sketches will be selected for publication from 
the wealth of material which Lord Bryce left. There 
is ample room among works of travel for these de- 
lightful sketches. 
The Appearance of Mind. By James Clark M‘Kerrow. 
Pp. xv+120. (London: Longmans, Green and 
Co., 1923.) 6s. net. 
Tus is a first book by a young author. It is a striking 
argument ably developed. It is almost a common- 
place in philosophy to deny the reality, in the sense 
of substantial or causal unity, of the object of know- 
ledge, and to reduce things to phenomena. Mr. 
M‘Kerrow holds that the notion of mind is even more 
misleading and less justifiable. It must be de- 
subjectified in a way which even Hume did not succeed 
in attaining. The immaterial principle which he 
would substitute for mind is “ viable equilibrium.” 
He denies that his theory is identical with behaviour- 
ism, which is equally anxious to disclaim mind, but 
he suggests that it may supply just what is wanting 
to behaviourism to make it work. 
The Chemistry Tangle Unravelled: being Chemistry 
systematised on a New Plan based on the Works of 
Abegg, Kossel, and Langmuir. By Dr. Francis W. 
Gray. Pp. x+148. (London: Longmans, Green 
and Co., 1923.) 6s. net. ; 
Tuis book is mainly an exposition of the work of 
Kossel. In spite of its title, it does not throw any 
new light on chemical problems, and the student would 
be well advised to read the original papers of Kossel, 
Lewis, and Langmuir rather than to attempt to absorb 
their theories in the less attractive form in which they 
are presented by Dr. Gray. 

