388 
near it, the other repels,” leaving the reader to wonder 
why they do not both attract or do not both repel, or, 
indeed, why on earth they do either. 
The plan of describing instruments and their working 
instead of the principles involved is to be deprecated in 
elementary text-books. At the very outset (p. 5) a de- 
scription of how a tuning-fork is run by an electric 
current is given, with an explanation of the mode of 
action which, were it true, would mean that the vibration 
of the fork could not be kept up by the current. It seems 
unnecessary at the start to introduce the question at all, 
but if it must be so, the student should certainly be 
wained of the necessity of supposing some lag in the 
current. 
One or two serious errors have crept in and must be 
altered in any future edition. In describing rigidity, the 
ordinary definition of a simple shear is given, but what 
follows will certainly bewilder the student. 
“When a pair of steel shears or scissors is used, the 
force applied is distributed over a very small area, the 
area of the ‘edge’ of the shears, so that the shearing 
stress (per sq. cm.) is great, and the finer the edge the 
greater the stress becomes ; consequently the material 
so stressed can be cut.” 
The area here spoken of is at right angles to the area 
meant in the definition, and in fact has nothing to do 
with the simple shear. Besides, the action in question is 
in reality anything but a simple shear. 
Another passage requires rewriting. The air supplied 
to an organ pipe is spoken of as 
“setting in motion a reed fixed in the end, or if there be 
none, the ‘lip’ or thin lamina of wood or metal near the 
front aperture of the pipe.” 
One misses the old familiar fundamental experiments 
of the text-books, and in many cases this absence is to 
be regretted. Thus, at p. 251, the attractions and repul- 
sions of electrified bodies are not described as funda- 
mental observations, but follow as corollaries in rather a 
cart before the horse fashion from the assumed shortening 
and swelling of things called lines of force. The student 
is given a picture of lines of force, and is told that it is 
“evident that positive and negative charges attract each 
other.” 
On p. 233 the metals have got evidently inverted, when 
it is said that “both soft iron and steel show retentivity, 
the former to even the greater extent of the two.” 
It is errors such as these which are just the ones which 
trouble the student. 
From what has been said it might be inferred that the 
book was found to be without interest ; such is not the 
case. With some alteration it is easy to imagine it 
made into a thoroughly useful one, especially for medical 
students, for whom it was more particularly written. 
The chapter on chemical physics is splendid and forms a 
most excellent introduction to the subject. The chapter 
on light is also good. Here the diopter system is intro- 
duced with effect; the parts touching on geometrical 
optics are simply described, no proofs being given. This 
has much to commend itself in a book of this scope, 
but at the same time the average student must not be 
asked to draw conclusions without being carefully given 
the premisses, as at p. 281, where he is told without 
NO. 1712, VOL. 66] 
NATURE 
[AucusT 21, 1902 
further ado that “the distance BF is called the focal 
length and in case of a mirror is clearly half the radius of 
curvature.” A first-class student will see there is some- 
thing to prove and will prove it; others will not do 
either. This sort of thing tends in the long run to 
woolliness in thinking. 
The book is well printed and the diagrams are good. 
There are few misprints ; the following, however, were 
noticed and are given with the view of correction ina 
future edition. On p. 41, 2. 32, heads should be altered 
to beads ; p. 60, /. 21, 19°57 to 195°°7 ; p. 78, 7. 17, T to 
P; p. 141, 7. 35, 0°93 to ‘093; p. 267, 7.5, EtoF. 
On p. 180, 7. 11, 48 watts per hour are spoken of ; “per 
hour” should be omitted. 
On p. 240 we find it stated that if a wire of length Z be 
moved across a field of strength H, ‘‘the electromotive 
force due to a motion of 1 cm. will be proportional to 
7H”; ‘per sec.” has dropped out. 
THE VOICE AND RESPIRATION. 
Health, Speech and Song: a Practical Guide to Voice- 
production. By Jutta Bell-Ranske. Pp. 158. (London: 
Swan Sonnenschein and Co., Ltd. ; New York: E. P. 
Dutton and Co.) Price 4s. 6d. net. 
LTHOUGH the subtitle of this book is “ A Practical 
guide to Voice-production,” the space is chiefly 
occupied by a description of the organs of voice and 
respiration, accompanied by statements of the somewhat 
peculiar views of the author as to the anatomy and 
physiology of these organs, and criticisms of the views 
of the many schools of voice-production. There are but 
a few pages devoted to giving practical instructions on 
the training of the voice, and what little is said upon this 
subject is too vague and general to be of much service. 
The book throughout is written in a very rhapsodical 
fashion, so much so that it becomes exceedingly difficult 
to trace out any meaning in some of its passages, while 
in other cases the effect produced can only be described 
as ludicrous. 
The following passage may be cited as illustrating 
this :— 
“ Since I have stated that the vocal instrument consists 
of three elements, it might at first appear that each ele- 
ment must be of equal importance. And if the motor 
element which drives the organ were given us for the sole 
purpose of creating song, it would be so, but this element 
has a far more important function, being the element 
of life itself; hence song becomes only an overflow of 
life. Life is breath.” 
The author repeatedly deplores the ignorance of physi- 
ology shown by voice trainers, but the physiological 
statements made in the book are often very peculiar and 
occasionally erroneous. Thus it is stated on p. 27 that 
“The diaphragm flattens, that is, is drawn down. The 
chest is expanded upwards, downwards and outwards, at 
the expense of the abdomen. The floating ribs, which 
are attached to the outer rim of the diaphragm, are 
pressed forward and outwards, thereby greatly expanding 
the bases of the lungs, an act which constitutes rib or 
costal breathing.” 
Other statements in the book (p. 28, ef seg.) clearly 
show that the author confuses costal and diaphragmatic 
breathing, regarding these as identical and to be care- 
