414 
seventeen have both liquid and solid waste, and in the 
greater number of these the liquid waste preponderates. 
But those industries selected by the author for special 
treatment are undoubtedly among the greatest sinners as 
regards possible river pollution. Their waste is, as a 
rule, particularly difficult to deal with, and a study of the 
means adopted in the several instances presents many 
features of interest to the sanitary and municipal 
engineer. 
The work has been judiciously put together, and the 
examples of plant selected for special description are in 
all cases typical examples of their class. It is admirably 
printed and illustrated, and the diagrams and drawings 
are such as will commend themselves to the practical 
man. The work is specially addressed to borough 
engineers and surveyors, and we trust that it will be as 
widely read and studied by them as it deserves to be. 
OUR BOOK SHELF. 
Die Weltherrin und thr Schatten. Ein Vortrag uber 
Energie und Entropie. Von Dr. Felix Auerbach, 
Prof. a. d. Universitat Jena. Pp. 56. (Jena: Gustav 
Fischer, 1902.) Price Mk. 1.20. 
Dr. AUERBACH no doubt undertook a very difficult task 
when he endeavoured to popularise the exact significance 
underlying the expressions “energy ” and “ entropy,” and 
the relations subsisting between them, and it is not easy 
to say how far he has succeeded in making himself 
intelligible to an unscientific audience. Doubtless, of 
energy everyone believes himself to be more or less well 
informed, but of entropy, though perhaps not really 
more difficult of apprehension, yet from its less familiar 
use very great perplexity and uncertainty seem to 
exist. We can only hope that the author dissipated some 
of the clouds which hover around this intricate subject. 
The somewhat fanciful title of “The Mistress of the World 
and her Shadow” which is attached to the address leads 
one to expect a more picturesque and imaginative treat- 
ment than the subject receives. One looks naturally for 
a new set of metaphors and illustrations by which a 
rather dry subject may be illuminated and its treatment 
rendered more entertaining, but one does not find much 
that is new or very appropriate, though of course the 
matter is sound, and doubtless as a popular address the 
lecture was very effective. 
We are glad to see that it has since been published in 
Himmel und Erde, where it is likely to meet with many 
and appreciative readers, and thus reach a wider audience 
than is possible in a lecture theatre. The authoritative 
version is accompanied by a short list of works connected 
with the general subject, and also some pages of explana- 
tory notes from the professor addressed to those who are 
supposed to have some slight previous knowledge of the 
subject. Notes attached in this way are usually a tacit 
admission on the part of the author that he has failed to 
accomplish the task that he has undertaken. We see no 
reason to view these notes in a different light. 
Chemisch-Analytisches Praktikum. Von Dr. Karl Anton 
Henniger. Pp. viii + 127. (Brunswick: F. Vieweg 
und Sohn, 1902.) Price Mk. 1.50. 
THE chief interest of this book lies in the fact that the 
author is head-master of the Charlottenburg Real Gym- 
nasium, and that the .course which he describes is the 
one adopted in that institution. We have thus an oppor- 
tunity of seeing what kind of practical chemistry is 
cultivated in one of the first-class German schools. 
According to the author, the goal to be reached by the 
NO. 1713, VOL. 66] 
NATURE 
[Aucust 28, 1902 
great majority of his pupils is a knowledge of the chief 
reactions of the non-metals and metals, as well as sure- 
ness and clearness concerning the procedure of analysis 
and the use of the distinguishing reagents. This is to be 
effected by exercising in simple analysis. 
If this be the case, it may be said that the book is well 
calculated to fulfil its purpose, for it is substantially a 
treatise on qualitative analysis prefaced by some useful 
exercises on different types of chemical action. Descrip- 
tions and equations are given for all the tests that are 
to be performed, and the pupil is, in fact, put through a 
regular analytical drill, The amount of detail is sur- 
prising considering that we are concerned with school- 
work, and it is difficult to see what would be left for the 
university to teach in the way of qualitative analysis if 
the students came with a mastery of this book. 
It is remarkable that the course of chemistry here 
prescribed for school purposes is of the kind that, with 
pretty general approval, has been steadily disappearing 
from English schools during the past fifteen years. In 
this corner of education Germany can hardly be said to 
show the way. A. S. 
La Protezione degli Animali, By N.Lico. Pp. viii + 64. 
(Milan: U. Hoepli, 1902.) 
THE appearance of this “booklet” may be taken as an 
indication that the proper treatment by man of the in- 
ferior animals and the avoidance of unnecessary and 
wilful cruelty are attracting attention in countries other 
than our own. Indeed, Turin, like Paris, possesses its 
own Society for the Protection of Animals, and the 
crusade against bearing-reins and other forms of minor 
_torture is carried on as vigorously (and, shall we say, as 
vainly) as in London. 
The author commences with a chapter on the duty of 
humanity to animals in general, and then proceeds to 
discuss the various groups of animals brought more 
especially into contact with man, and the cases where 
amendment in their treatment is most urgently required. 
In general, the arguments appear to be put temperately 
and moderately, even in regard to that thorny subject vivi- 
section. Such sports as dog-racing (under the conditions 
in which it is conducted in some continental countries), 
cock-fighting and bull-fights the author unhesitatingly 
condemns. He is likewise averse to all mutilations 
of animals, whether to “ improve” their appearance or for 
other reasons. But minor matters, suchas the treatment 
of horses by cavalry soldiers and coachmen, and the 
nature and fitting of their accoutrements and harness, 
claim a share of attention. Whether the author will 
succeed in convincing the world that a vegetarian is 
preferable to an animal diet may be more than doubtful, 
but if the book leads to a diminution in any degree of 
certain forms of cruelty to animals from which this country 
at any rate is free, its publication will not have been in 
vain. R. L. 
Coal Cutting by Machinery in the United Kingdom. By 
Sydney F. Walker. Pp. 144. (London: The 
Colliery Guardian Co., Ltd., 1902.) 
THE complaint has frequently been made against mine 
owners in this country that they are not availing them- 
selves of coal-cutting machinery to anything like the 
same extent as mine owners in the United States. The 
complaint is justifiable, inasmuch as any methods by 
which labour and capital can economise are now abso- 
lutely necessary. In his excellent monograph on coal 
cutting by machinery, Mr. Walker shows that the 
question is by no means new to this country. The 
history of the coal cutter in Great Britain is an ancient 
one. Indeed, the earliest proposal to substitute the 
labour of a machine for that of a collier appears to have 
been made by Michael Menzies, of Newcastle-on-Tyne, 
