FEBRUARY 7, 1907 | 
NATURE 341 
OUR BOOK SHELF. 
Minerals and Metals: a Reference-book [of] Useful 
Data and Tables of Information. A condensed 
compilation from various sources by J. G. Goesel. 
Pp. xiii+287. (New York: John Wiley and Sons; 
London: Chapman and Hall, Ltd., 1906.) Price 
12s. 6d, net. 
Tue scope of this pocket-book of reference may be 
best indicated by quoting from the title-page :— 
‘“Legal, customary, and _ scientific measurements; 
geological classification ; rock composition; chemistry, 
dry and wet assay; mineralogy; metallurgy; metal 
founding and plating; hydraulics; water purification ; 
mineral oils; gases; explosives; strength of materials, 
including woods, their properties, adaptability, and 
preservation ; pigments, gums, and solvents for paints 
and varnishes; miscellaneous data and receipts.’ It 
will thus be seen that the variety of subjects treated 
is much more extensive than is indicated by the main 
title, ‘‘ Minerals and Metals’’; in fact, there is, in 
a handy form, a vast amount of information which 
may be of use to mining engineers and others. 
Books of this kind should, of course, be free from 
ambiguities and errors, but in the portions which we 
have specially tested, namely, those dealing with 
minerals and precious stones, numerous errors have 
been detected; quite extraordinary chemical formulze 
are given for even common minerals, whilst in the 
spelling of names there are many misprints. 
The bool is clearly printed, though not on thin 
paper, and is well bound in limp leather, with rounded 
corners and gilt edges. 
Practical Exercises in Chemistry. By G. C. Doning- 
ton, Senior Science Master in the Leeds Grammar 
School. Pp. x+251. (London: Macmillan and Co., 
Ltd., 1906.) Price 2s. 6d. 
Mr. Donineton’s little book derives special interest 
from the fact that whilst he is a pupil, and a very 
grateful one, of Prof. Armstrong, he has found him- 
self compelled by experience as a science master in a 
school (and one in which no specially unfavourable 
conditions prevail) to depart from the practice of leav- 
ing the pupils without a text-book during their prac- 
tical lessons. This experience is, we believe, by no 
means uncommon, and it is an advantage that the 
“felt want ’’ should be supplied by one who naturally 
strives to conserve as much as he can of the merits 
of the no text-book system. In this object the author 
has, we think, had good success, and his book is 
likely to take high rank among those which of late 
years have been written to set forth an elementary 
course of chemistry for those secondary schools where 
there is a desire to teach scientific method through the 
medium of this science. 
Paradoxes of Nature and Science. By Dr. W. 
Hampson. Pp. xv+304. (London: Cassell and 
Co., Ltd., 1906.) Price 6s. 
Dr. Hampson proposes to explain to the uninitiated 
certain scientific ‘* paradoxes.’’ The only possible 
“explanation”? of such paradoxes is attained by 
showing that the abnormal phenomena are deter- 
mined by precisely the same laws as the normal 
phenomena; to ‘‘explain’’ why a balloon rises it is 
necessary to propound the general principles of gravi- 
tational mechanics and to show that it rises for the 
same reason as a stone falls. But Dr. Hampson 
eschews general principles. His ‘‘ explanations ’’ are 
appeals to prejudices as unscientific as those which 
gave rise to the appearance of a paradox. Even when 
his arguments are sound they must convey to a reader 
a wholly untrue idea of scientific method. 
NO, 1945, VOL. 75] 
But they are not always sound. Sometimes he 
wanders far out of his depth, as, for instance, when 
he seeks to solve the old logical contradiction of 
Achilles and the tortoise by a reference to the atomic 
structure of matter. He would have done well to 
restrain his jeers at mathematicians until he had 
gained some acquaintance with the elements of their 
science. 
Seasonal Botany, a Supplementary Text-book. By 
M. O’Brien Harris. Pp. 56. (London: Blackie 
and Son, Ltd., 1906.) Price 8d. 
PropaBLy most teaching botanists looking back upon 
their early experiences when they first found it neces- 
sary to draft a syllabus of instruction can recall an 
attempt to prepare a course adapted to the round of 
the seasons. In the case of pure observational study 
such a course is profitable, but it is the general ex- 
perience that a seasonal adjustment does not accord 
with the best morphological or physiological sequence, 
and this opinion is not modified by the arguments or 
scheme put forward in the present instance. 
The seasonal syllabus given in the form of a tabu- 
lated scheme, and a number of physiological experi- 
ments on very usual lines, form the chief contents 
of the book. 
French Readings in Science. Selections from Scien- 
tific and Technical Writers, arranged and edited 
for the Use of Students. By de V. Payen-Payne. 
Pp. vii+230. (London: Blackie and Son, Ltd., 
1906.) Price 3s. 6d. 
IGNORANCE of either French or German is a serious 
handicap to the scientific worker. University examin- 
ing bodies are recognising this need, and some, such 
as the University of London, demand from candidates 
for science degrees a knowledge of these languages 
sufficient to enable them to translate with fair ease 
and accuracy. In making his selection of passages 
from scientific treatises, Mr. de Payen-Payne has 
included some extracts for their modernity, and others 
because of their association with great names in 
science. The compiler is catholic in his tastes, and 
his work should provide students with just the practice 
they require. 
LETTERS TO THE EDITOR. 
{The Editor docs not hold himself responsible for opinions 
expressed by his correspondents. Neither can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts intended for this or any other part of NATURE. 
No notice is taken of anonymous communications.] 
Radium and Geology. 
Tuosr interested in this subject should refer to the 
paper which appears in the last issue of the Philosophtcal 
Magazine, by Mr. A. S. Eve, on the ionisation of the 
atmosphere over the ocean. Mr. Eve cites observations, 
and adds others of his own, showing that the ionisation 
over the ocean is much the same as over the land, and 
points out the difficulty of explaining this in view of the 
small content of radium in sea-water compared with that 
in ordinary rocks. Possessed as | am with the view that 
extra-terrestrial radio-active dust reaching the earth may 
account for much of the radium of soils, sediments, and 
rocks, I cannot but think that Mr. Eve’s difficulty may 
find explanation in an extra-terrestrial source of supply. 
Mr. Eve also gives some new determinations of the 
radium in sea-water, and arrives at results which con- 
siderably accentuate the discrepancy which I referred to 
