78 NATURE 
to an end when the introduction of lucifer matches 
made it easy to read an ordinary watch at night. 
There is a chapter dealing with the artistic side of the 
subject, and describing several clocks and watches 
of special interest and beauty. It is altogether a 
book that will appeal to the general reader quite as 
much as to those specially interested in time-determina- 
tion. ANC. DAC. 
Anthracite and the Anthracite Industry. By A. Leonard * 
Summers. (Pitman’s Common Commodities and 
Industries Series.) Pp. x+126. (London: Sir 
Isaac Pitman and Sons, Ltd., 1922.) 3s. net. 
Tuts book seems to be a combination of a scientific 
manual and a coal-dealer’s propaganda circular. With 
some useful information about anthracite, we find 
other matter—on p. 26 a statement that in rg2r the 
South Wales coal-owners were losing 25,000,000. 
a year because of “unwanted young men— hot- 
heads’ and agitators’ in the mines—an example of 
“what the industry is up against’; on p. 69 we 
have a series of testimonials in the approved style, 
and “tourist facilities in the beautiful anthracite 
district in Chapter II. The printing of advertisements 
on the reverse of the title-page is also distracting. 
When information about anthracite is encountered 
in the book it proves interesting, but some patience 
is required to find it. ‘‘ Tar,” we are told on p. 112, 
“also contains chemicals, such as carbolic acid and 
saccharine.” 
Polarity. By Geoffrey Sainsbury. Pp. 48. (London : 
The Favil Press, Peel Street, W. 8., 1922.) 35. 6d. 
MR. SaINsBuRY’sS artistically printed little book consists 
of a series of short essays on sex, religion, education, 
society, and ethics. The point of view of the author is 
unusual and independent, and it demands that the 
reader’s mind should free itself from many placidly 
accepted concepts. Polarity, the author thinks, has 
never been adequately considered, as man invariably 
tries to bring the problem of life and all attendant 
problems down to a single issue. Polar conflict is to 
be seen everywhere, and innumerable problems hinge 
upon this relationship and to none of this type can 
there be any final answer. There is also a plea for a 
willingness to see knowledge from a more general, 
instead of the extremely specialised, point of view. 
There will be many readers who will dissent from the 
views here set forward, which will certainly stimulate 
thought. 
Man—The Animal. By Prof. W. M. Smallwood. Pp. 
xv +223. (New York: The Macmillan Co.; London: 
Macmillan & Co. Ltd., 1922.) 12s. net. 
Pror. SMALLWOOD’s little book is interesting but con- 
fessedly “‘ popular,” and therefore fraught with the 
difficulties that are inseparable from all “ popular ” 
presentations. Its object is to summarise the dis- 
coveries of recent years, to indicate some of their 
relations to the more fundamental problems of man’s 
physical existence, and to give a deeper insight into the 
characteristics which man has in common with all life, 
and which exercise a profound influence on his entire 
existence. The chapters on reproduction, heredity, 
NO. 2777, WOle Trt] 
[JANUARY 20, 1923 
the problem of learning, and biology and progress are 
especially well done. The whole book, though not 
absolutely free of error, is worth reading, and will be 
especially appreciated by readers possessed of biological 
knowledge. , _e 
Chemistry and its Uses. A Text-Book for Secondary 
Schools. By W. McPherson and W. E. Henderson. 
_ Pp. viiit+447. (London: Ginn and Co., 1922.) 
{ 75. 6d, net. 
THE text-book before us is intended for use in American 
high-schools, and would probably be very suitable 
for that purpose. It is written from the point of view 
of the patriotic American, and naturally refers prin- 
cipally to American conditions. There are some repro- 
ductions of portraits of well-known chemists. Each 
chapter is provided with exercises, and a rough equality 
of division is adopted between pure and applied 
chemistry (including organic chemistry, treated very 
superficially). There are numerous illustrations of 
labelled bottles: even assuming that these contained 
what is represented when they were photographed, 
the value of the pictures is not at all clear. Surely 
it is not intended that they shall replace actual ac- 
quaintance with real substances? The actual text 
is clear and accurate, so far as it was examined, and 
the book would interest English teachers. 
Chemistry for Beginners and Schools (with Glossary). 
By C. T. Kingzett. Fourth edition. Pp. vii+237. 
(London : Bailliére, Tindall and Cox, 1922.) 5s. net. 
THE continued demand for Mr. Kingzett’s book 
indicates that it is serviceable to numbers of readers. 
It is clearly written, and contains many interesting 
experiments. The glossary will also be found useful 
by beginners; surely, however, “ lixiviate”’ is com- 
moner than “lixurate” (p. 212)? The section on 
“Force and Energy” (pp. 34-52) requires revision. 
It is very much out-of-date in parts, and not up to the 
standard of the rest of the book: the statement that 
“electricity, like heat and light, is a form of force ” 
(p. 45), although it may have been true for Faraday, 
is not so to-day. The book is scarcely suitable for 
schools, as it provides no systematic course—the 
experiments are introduced at random. 
Concrete and Reinforced Concrete. By W. N. Twelve- 
trees. (Pitman’s Common Commodities and In- 
dustries Series.) Pp. x+137. (London: Sir Isaac 
Pitman and Sons, Ltd., n.d.) 3s. net. 
THE general reader will find a great deal of interesting 
matter in this book, which is explanatory and practic- 
ally free from calculations. Sufficient is given to 
make clear the nature of the materials employed and 
their combination, and the author has included a 
number of examples of finished work which convey a 
very good impression of the extent to which concrete 
and reinforced concrete have been employed, and of 
their possibilities. 
from which we gather that the ancient Egyptians were 
thoroughly familiar with concrete, as is proved by a 
fresco in the temple of Ammon at Thebes, depicting 
hieroglyphically the making and use of concrete in 
the year 1950 B.C. 
There are some historical notes, ~ 
