NOVEMBER 2, 1916] 
earthly mysteries, and that what we call beauty, 
whether of sound or form, is but its resultant and 
expression. It was in the very spirit of Pytha- 
gorean mysticism and wisdom that that great 
naturalist, Henri Fabre, wrote his great ode to 
number; as in a kindred spirit the old carpenter 
in Verhaeren’s poem : 
“Fait des cercles et des carrés, 
Tenacement pour démontrer 
Comment 1|’4me doit concevoir 
Les lois indubitables et fécondes 
Qui sont la régle et la clarté du monde.” 
We must never forget that the secrets of the 
mystic, whether Gnostic, Cabbalist or Pytha- 
gorean, lie very deep indeed, and that a twin 
alternative between esoteric and exoteric state- 
ment, or between literal and allegoric interpreta- 
tion, by no means exhausts the various meanings 
which the mystical philosopher can wrap up in his 
words. In the end, as we come slowly to a better, 
though still a clouded, understanding of what lies 
within and behind the Golden Verses and all the 
rest of the husk of Pythagorean tradition, we feel 
the truth and force of William James’s saying 
{aptly quoted in the article to which I have just 
referred), that the ‘‘ mystical classics have neither 
birthday nor native land; their speech. antedates 
language, and they do not grow old.’”’ 
D’Arcy W. Tuompson. 
PHYSIOLOGICAL CHEMISTRY. 
Physiological Chemistry: A  Text-book and 
Manual for Students. By Prof. A. P. Mathews. 
Pp. vii+1040. (London: Bailli¢re, Tindall and 
Cox, 1916.) Price 21s. net. 
ROF. MATHEWS is well known as a worker 
in the field of physiological chemistry, more 
especially on its physical side. His present 
volume is one of an ambitious character, and has 
the merit of being distinctly original. The chap- 
ters on the chemistry of the fats, carbohydrates, 
and proteins are fuller than is usual in such hooks, 
and the subject-matter is not only clearly ex- 
plained, but is fully up to date. Much of it is 
pure chemistry, but it will not be less valuable for 
that reason to the biologist. The section on 
physical chemistry is also treated at considerable 
length, as might have been anticipated by those 
who know the author’s bent. The whole subject is 
confessedly treated unequally, for, as the preface 
puts it: “Of so large a subject one can. be per- 
sonally familiar with but a small part.” The por- 
tions that strike one as susceptible of more expan- 
sion are those dealing with muscle and the duct- 
less glands; for the latter group of organs Prof. 
Mathews coins yet another name: he dubs them 
the Cryptorhetic Organs—i.e. organs with a 
hidden flow. One small feature of the book—viz. 
the explanation and derivation of technical terms 
—might well be imitated in more elementary 
manuals than the present. While on the question 
of words, one may add that the nomenclature 
-adopted for the fats and fat-like substances is one 
not likely to commend itself to all physiologists. 
NO. 2453, VOL. 98] 
NATURE 
167 
Each chapter is followed by a short selected list 
of papers bearing on the subject dealt with in that 
chapter. There is no attempt at a complete 
bibliography, but the selections appear to have 
been judiciously made, though in the present state 
of the political atmosphere German writers figure 
rather too largely for English taste. The papers 
mentioned for reading and study are mostly recent 
ones, because they approach the subject from the 
modern point of view, and in them the older litera- 
ture is cited. The choice does not imply that the 
author does not value the work of the early 
pioneers; indeed, he presents evidence that he 
takes the opposite point of view, and the full con- 
sideration which he gives to their work forms one 
of the most interesting features of his book. He, 
for instance, gives a very extensive account of the 
researches of Lavoisier, whom he perhaps rightly 
regards as the founder of bio-chemistry, of Beau- 
mont, of Claude Bernard, and many others. 
Prof. Mathews, who is here the exponent of a 
vast but nevertheless comparatively young branch 
of science which every day is becoming more and 
more exact, is not devoid of a sense of imagina- 
tion, the most valuable asset of both a teacher and 
a researcher. His excursions into the regions of 
speculation will be read with keen interest, even 
although, like so many hypotheses in the past, 
they may ultimately be forgotten. Such theories 
as those which he advances in his comparison of 
the animal body toa magnet, or in his conception of 
the ‘‘conservation of psychism,” or in his attempts 
to explain memory on a chemical basis, will cer- 
tainly stimulate thought and future investigation. 
To quote once more from the preface: “It is 
hoped that this book will raise in the mind. of those 
who read it more questions than it answers.” 
The last 160 pages of the book are devoted to a 
description of the laboratory work in physiologi- 
cal chemistry as carried out in the University of 
Chicago, and practical teachers will obtain many 
useful wrinkles by studying these. W. D. H. 
OUR BOOKSHELF. 
Cambridge Geological _ Series. Agricultural 
Geology. By R. H. Rastall. Pp. ix+ 331. 
(Cambridge: At the University Press, 1916.) 
Price 10s. 6d. net. 
Mr.. RastTaty’s. well-written and _ excellently 
printed book is a treatise on geology for agri- 
cultural students rather than on agricultural 
geology. To say this is no disparagement, since 
it is obviously intended for the stage in an agri- 
cultural curriculum when natural history subjects 
are predominant, and not for the later years when 
preliminary scientific conceptions are applied to 
the study of the soil. A knowledge of chemistry 
and elementary mineralogy is presupposed, but 
unnecessary technical terms are carefully ex- 
cluded. The final chapter, on “The Geological 
History of the Domestic Animals,” will appeal 
especially to those whose work is on the farm. 
The history of life on the globe is, indeed, far 
more appreciated by agricultural scholars than 
