JULY 4, 1912] 
NATURE 
449 
on the other hand, the work on metallic alloys 
by Gustav Tammann and several other investiga- 
tions, including a discussion of quadrivariant 
systems by Schreinmakers and De Baat, are new, 
and are included in this volume. Another change 
that has been gradually taking place has been the 
growing importance attached to the phase rule 
and its applications in the chemical industry, 
where many firms employ experts engaged in 
making theoretical calculations and not experi- 
ments only. 
(6) Volume 14 of collected works, 
issued under the auspices of the Prussian 
Academy of Sciences, is the first of a new series 
dealing with Kant’s manuscript relics. The first 
thirteen volumes comprise Kant’s principal works 
Kant’s 
and correspondence, and this volume includes all | 
those minor writings which refer to mathematics, 
physics, chemistry, and physical geography. 
A few of these, notably the mathematical ones, 
are what an examiner would describe as “rough 
work,” and the editor has evidently been at much 
trouble to interpret some of the fragments in the 
copious notes which go far to make up the bulk 
of the volume. 
OUR BOOKSHELF. 
The Calorific Power of Gas: a Treatise on Calorific 
Standards and Calorimetry. By J. H. Coste. 
Pp. xvi+ 310. (London: C. Griffin and Co., 
Ltd., 1911.) Price 6s. net. 
AN increasing proportion of coal-gas now manu- 
factured is used for heating and power purposes, 
in which the value of the gas is directly measured 
by its calorific value. Of the gas used for light- 
ing, the bulk of it is now burnt with incandescent 
mantles, and for this purpose the calorific value is 
a better measure of value than the direct photo- 
metric candle-power with an Argand burner. 
Hence the methods of measuring the calorific value 
of gas have assumed practical importance, and 
the present book supplies a distinct need. 
Gas supply being in this country a practical 
monopoly, and the gas consumer being unable to 
gauge the quality of the gas supplied to him, from 
a very early date the testing of gas has been sub- 
ject to statutory regulation, and in the opening 
chapters a clear and concise account is given of 
gas legislation. The relation between the present 
photometric standards and the equivalent calorific 
standards is then dealt with, and this is followed 
by a discussion of the changes in the mode of gas 
manufacture during the last sixty years as affect- 
ing the lighting and heating values. Then follow 
descriptions of the construction and mode of 
working of a considerable number of gas calori- 
meters of different types, special attention being 
given to those which have been most generally 
adopted. 
The author has had practical acquaintance with 
NO. 2227, voL. 89] 
all the types of instruments in general use, and 
gives the results of his experience, in many cases 
not previously published. The discussion on the 
sources of error affecting the results of flow calori- 
meters is especially valuable, as is also the account 
of the various “net values” which have been 
proposed. 
The work will be highly appreciated by gas 
engineers, gas examiners, and everyone concerned 
with the manufacture or testing of coal gas. 
Catalogue of the Chiroptera in the Collection of 
the British Museum. Second edition. By 
Knud Andersen. Vol. 1., ‘“ Megachiroptera.” 
Pp. ci+854. (London: Printed by Order of 
the Trustees. Sold by Longmans and Co. ; 
B. Quaritch, Dulau and Co., Ltd.; and at the 
British Museum (Natural History), 1912.) 
Price 2]. 10s. 
THE present account of the Megachiroptera, 
| although nominally a new edition of Dobson’s 
Catalogue published in 1878, isin reality an original 
monograph, and the trustees of the British 
Museum have been fortunate in securing for this 
work the services of Dr. Knud Andersen, whose 
name alone is sufficient guarantee for a careful 
and accurate revision of the group. 
In the introduction will be found a detailed dis- 
cussion of the general characters, the interrela- 
tions of the genera, the geographical distribution, 
and a synopsis and key, the latter based on dental 
and cranial characters only. 
The body of the work consists of new descrip- 
tions of 228 forms, and the subject-matter is 
divided for convenience of reference into specially 
marked paragraphs. The technical names are 
throughout fixed in strict accordance with the 
laws of priority. 
The work appears to have been extremely well 
done, and the author and Mr. Oldfield Thomas, 
without whose support it could not have been 
attempted, deserve very warm congratulations on 
the appearance of vol. i., and good wishes for 
the completion of the whole catalogue. 
The illustrations have been entrusted to A. J. 
Engel Terzi, and appear to be very satisfactory. 
Icones Plantarum Formosanarum nec non et 
Contributiones ad Floram Formosanam; ov, 
Icones of the Plants of Formosa, and Materials 
for a Flora of the Island, based on a Study of 
the Collections of the Botanical Survey of the 
Government of Formosa. By B. Hayata. 
Fasciculus i. Pp. iii+ 265+x1 plates. (Taihoku : 
Published by the Bureau of Productive Industry, 
Government of Formosa, 1911.) 
Previous to 1897, when the Japanese took pos- 
session of Formosa, the botanical exploration of 
the island was almost entirely due to British 
enterprise, but the savage inhabitants had pre- 
vented travellers from penetrating the moun- 
tainous interior. Since their occupation the 
Japanese have been very active in the investiga- 
tion of the natural products, and botanists have 
not been the least active. The botanical literature 
