392 
formed, Of the numerous native risings with which 
the company has had to deal, the most formidable was 
that headed by the redoubtable Mat Saleh, who was 
defeated and killed in 1899. 
Mr. Rutter gives a very complete account of the 
geography and economic resources of the country, of 
which, however, the greater part is still undeveloped. 
The native population offers many points of interest 
to the ethnologist. The Dusuns and Muruts, the up- 
country agricultural population, are of Indonesian 
stock. The coastal peoples, Bajau, Ilanun, and others, 
represent an incursion of Malayan stock. The latter 
are Mahommedans, while the former are pagan. A 
remarkable feature in the religious beliefs of some of 
the Dusuns is the cult of the sacred jar, in each of which 
a small company of relatives has a joint ownership. 
Incandescent Lighting, By S. I. Levy. (Pitman’s 
Common Commodities and Industries.) Pp. x +129. 
(London: Sir Isaac Pitman and Sons, Ltd., 1922.) 
35. net. 
THE author has produced an interesting and well- 
written book which gives a good historical account of 
the development of artificial lighting; particular 
attention being given to incandescent lighting. A 
chapter is devoted to the growth of the rare earth 
industry. The dramatic discovery of rich deposits of 
monazite in the British Empire, and notably at Travan- 
core in India during the War, was a great help to this 
country ; the sands at Travancore contain more than 
45 per cent. of monazite. The processes of extracting 
pure thorium compounds from monazite demand great 
ingenuity, and they are well described. Descriptions 
are also given of the recent great improvements in the 
manufacture of incandescent mantles. The author 
gives a very fair comparison of the costs of oil, gas, and 
electric methods of lighting. The average candle- 
power (formerly called the mean spherical candle- 
power) should, however, have been taken as the basis 
of the comparison and not the mean horizontal candle- 
power. 
Lubrication and Lubricants : a Concise Treatment on the 
Theory and Practice of Lubrication; the Physical, 
Chemical, and Mechanical Properties and Testing of 
Liquid and Solid Lubricants ; with Notes on Recent 
Developments and Examples from Practice ; for En- 
gineers, Chemists, and Students. By J. H. Hyde. 
(Pitman’s Technical Primers.) Pp. x+114. (Lon- 
don: Sir Isaac Pitman and Sons, Ltd., 1922.) 
2s. 6d. net. 
ALTHOUGH very uneven, the little book under notice is 
interesting. The definitions are usually rather care- 
lessly given, if at all. Thus, in the chemical section 
(which is not very satisfactory) neither the iodine nor 
the acetyl value is explained, although both are quoted. 
Langmuir’s name is incorrectly spelt throughout the 
book. The chapter on recent developments is of 
interest, and deals among other matters with the varia- 
tion of efficiency with temperature and the effect of 
adding vegetable to mineral oils. We have previously 
commented on the very ambitious titles of the small 
books in this series ; the remark applies in the present 
volume, and any one who expects what he might from 
the title will be disappointed. 
NO. 2786, VOL. 111] 
“NATURE 

[Marcu 24, 1923 

Molybdenum Ores. By Dr. R. H. Rastall. (Imperial 
Institute : Monographs on Mineral Resources with 
Special Reference to the British Empire.) Pp. ix+86. 
(London: J. Murray, 1922.) 5s. net. 
THE molybdenum minerals, their origin and mining, 
are dealt with, and an account of the metallurgy of 
molybdenum is also included in this work. The account 
of the electrical treatment on p. 5 does not seem com- 
plete, as no mention is made of the furnace charge. 
The sections on the sources of supply appear to be ex- 
haustive, nearly every reported occurrence of molyb- 
denum being mentioned, together with the production, 
if any. The table on p. 12 indicates that the demands 
for the metal are limited ; the production in 1918 was 
equivalent to about 800 metric tons of metal ; that in 
1921 was only 7 tons. The principal use is in the pre- 
paration of special steels ; a lower amount of molyb- 
denum will replace tungsten in a high-speed tool steel, 
and a small amount of molybdenum is said to improve 
a mild structural steel. 
History of Chemistry. By Dr. F. P. Venable. Pp. 
vii+169. (London and Sydney: D. C. Heath and 
Co., 1922.) 5s. net. 
Dr. VENABLE’s “ History of Chemistry ” is a second 
edition of a book that appeared in 1894. A history of 
chemistry which contains no illustrations or diagrams, 
and in which formule are used only in the few 
passages where their historical development is under 
consideration, must be subject to serious limitations 
and in the nature of things cannot be much more than 
a sketch. It is not quite clear to the reviewer what 
type of reader will be attracted by such a sketch ; but 
it is likely that the well-read student of chemistry will 
find some interest in this brief outline, and may be led 
by it to follow up the history of his science in some 
volume in which more details are given. 
The Elements of Scientific Psychology. By Prof. Knight 
Dunlap. Pp. 368. (London: Henry Kimpton, 
1922.) 18s. net. : j 
Tue author has here produced one of the best and 
most useful of the many text-books now available on 
psychology. He is a good experimentalist, and is 
thoroughly alive to the importance of a knowledge of 
physiology to the psychological student. He shows 
himself able at the same time to maintain a distinctively 
psychological point of view. The main faults of the 
book are that it attempts to cover too much ground, 
and that occasionally it presents, as text-book material, 
conclusions which require to be subjected to much 
further research. 
Grundxige einer Physioklimatologie der Festlander. 
Von Dr. Wilh. R. Eckardt. Pp. v+123. (Berlin: 
Gebriider Borntraeger, 1922.) 4s. 6d. 
Dr. Ecxarpt has produced a useful little book, which 
aims at giving an outline, according to the most recent 
investigations, of the distribution of temperature, 
pressure, and precipitation in the main land-masses. 
Particular attention is paid to Europe. There are a 
number of sketch maps and diagrams, and a short 
bibliography. The book gives in a convenient and 
authoritative way information that is not generally 
accessible in a collected form. It should prove very 
acceptable to students of geography. 

