OcTOBER 23, 1902] 
WATURE 
629 
If he is puzzled by the production of sodium salts from 
potassium thiosulphate, and turns to the fuller account on 
p. 85 for elucidation, he is confronted by the equation 
2CuSO,+4K=Cusl,+2K,S0, +21. 
In the subsequent directions, moreover, no attempt is 
made to shorten calculation by the use of a normal 
standard solution or of one that will enable the per- 
centage of copper to be read off from the burette. The 
student is told to “ Dissolve [o’5 grm. copper] in 5 c.c. 
nitric acid and boil till all nitrous fumes are expelled,” 
a dangerous piece of advice, and one that contains no 
hint of the practice now often preferred of getting rid of 
the nitric acid by means of sulphuric acid and so re- 
moving all chance of the disconcerting return of the blue 
colour. The dangers of terseness are also shown in the 
account of the estimation of lead as lead sulphate, on 
p. 64, where the directions are as follows:— '° 
“The solution is evaporated with sulphuric acid till 
the fumes of the acid are given off. The solution is 
diluted with water, allowed to settle, filtered, washed by 
decantation with water acidulated with sulphuric acid, 
and finally on the filter with dilute alcohol or water,” and 
so forth. 
These directions are inadequate, and it may be doubted 
whether either Prof. Rhead’s or Prof. Sexton’s students 
have ever been set to work without a fuller and more 
careful account of the precautions to be observed. 
Among other blemishes, the omission of all reference 
to Mulder’s neutral point in the Gay-Lussac method of 
estimating silver may be mentioned, and the importance 
of check assays in this method is not sufficiently 
insisted on. 
However, all these faults do not prevent the book 
from being useful both as asupplement to oral laboratory 
teaching and as a book of reference to experienced 
assayers. It is divided into three parts, part i. being 
devoted toa brief description of laboratory appliances 
and general processes, part il. tothe assay of the more 
important metals as well as chlorine and sulphur, and 
part iii. toa short account of certain analyses which have 
to be made in practice in metallurgical works. Of these, 
part ili. is perhaps less satisfactory than the others, but, 
although it is far from complete, there is much useful 
information in it, and speaking generally, analytical 
chemists and assayers will not regret the addition of the 
volume to their bookshelves. sleek. R. 
OUR BOOK SHELF. 
The Climates and Baths of Great Britain. Vol. ii. 
Pp. xvi + 628. (London: Macmillan and Co., Ltd., 
1902.) Price 12s. 6d. net. 
THIS volume completes the work undertaken by the 
committee of the Royal Medical and Chirurgical Society 
of London in 1889. The general arrangement of the 
subject-matter is on the same plan as in vol. i., and in 
order to maintain this uniformity the meteorology of the 
same series of years (namely, 1880-1890) has been 
investigated. 
The volume deals with London and Middlesex, the 
east coast, the midland counties, Lancashire, the lake 
district, Northumberland, North and South Wales, 
Ireland—including its mineral springs ; and the whole of 
the work has been placed in the hands of contributors | 
NO. 1721, VOL. 66] 
whose names are well known in the medical world. It 
should be added that seven excellent maps, showing 
areas, elevations, rainfalls and isothermals, are also in- 
corporated. 
The local information contained in this and in the former 
volume was mainly collected by means of circular letters 
sent to medical men practising at the various health 
resorts and bath-places, in which they were asked their 
opinion as to the prevalence of certain diseases ; the 
influence of the climate upon patients sent there for the 
treatment of different diseases ; the common causes of 
death and frequency of old age among residents ; the 
system of drainage ; the water supply ; and the local 
climatological data. Where medicinal baths exist, 
inquiry was made as to what morbid conditions are 
treated with advantage by these baths, the ways in which 
the waters are employed, the diseased conditions con- 
traindicating their use, and the time of the year advised 
for their application. 
The chapter dealing with London and Middlesex is 
certainly one of the best. The writer, Dr. William 
Ewart, remarks that in London “ everything is artificial,” 
from the “made ground” upon which it 1s built to its 
water courses, some of which are turned away from their 
natural beds, and to the composition of its air, so much 
altered by smoke, London fogs and mists, that the 
meteorology of London is one saz generis. Dr. Ewart 
asks, why should life in London be, on the test of 
mortality, so much safer than in many other districts ? 
This he considers to be partly explained by the relative 
dryness and warmth prevailing in the streets ; and he 
concludes that, with all its faults, its climate is a pro- 
tective one, with less exposure, greater warmth and less 
humidity than is the case in many other districts. 
The work is undoubtedly a valuable one, and well 
repays the large amount of time and labour which must 
have been devoted to its compilation. It will be found 
alike serviceable for reference to medical practitioners 
and their patients, and alsoto medical officers of health 
and local sanitary authorities, who are so largely in- 
terested in the health of the communities under their 
charge. The only respect in which this useful work 
leaves something to be desired is that the information 
should be of a more definite character than that furnished 
with reference to the prevalence of disease in some of 
the localities dealt with. 
Electric Wiring: a Primer for the Use of Wiremen and 
Students. By W. C. Clinton, B.Sc. Pp. viii + 179. 
(London : John Murray, 1902.) Price ts. 6d. 
ELECTRIC wiring is not a very suitable subject on which 
to write a primer. From the wireman’s point of view it 
is a subject to be studied only by practical apprentice- 
ship; from the engineer’s it is a special branch of 
electrical work to be taken up at a time when 
primers are things of the past. Nor do we quite see 
the right of such a book to a place in Mr. Murray’s 
“Home and School Library,” which is intended (as 
an advertisement sets forth) for the general reader as 
well as for school use. The general reader does not 
want to know how to make joints, and the schoolboy 
would be far better employed learning the first principles 
of electricity instead of the elementary details of one of 
its practical applications. Apart from considerations 
such as these, it must be admitted that Mr. Clinton has 
done his work well and written an interesting little book. 
He deals with wiring for both electric light and electric 
bells, and as these between them involve the principles 
of electricity, magnetism and electrochemistry, he has 
said a few words about the theory of all three subjects, 
and has strengthened these by the addition of some 
worked examples of an elementary character. The 
theoretical parts are necessarily brief, the bulk of the 
book being devoted to descriptions of the practical 
