DECEMBER 3, 1903] 
NATORE 
101 
eS 
As an important cause of baldness in men, the author 
places the wearing of stiff and heavy hats, which for 
hours together compress the blood-vessels of the scalp 
and impair its nutrition and that of the hair. 
points out that the common straw hat is often re- 
sponsible for as much compression as the cylinder 
hat. 
The part played by general organic and nervous | 
diseases in causing baldness and premature greyness | 
is considered, and these conditions obviously demand 
treatment at the hands of the physician. The rédle of 
micro-organisms in the production of baldness is 
perhaps insufficiently dealt with in the light of the 
work of Sabouraud and others in seborrhcea. Atten- 
tion is, however, directed to the effects of the parasites 
of ringworm and favus. But in these diseases and in 
alopecia areata the patient will naturally seek medical 
advice. 
Though the work is obviously written as a popular 
treatise, its perusal will be of value to the medical | 
practitioner, who very rarely gives attention to the 
subject, which is one of great interest to the public, 
who are only too ready to fly to various nostrums 
brought to their attention by assiduous advertisement. 
Radiant Energy. A Working Power in the Mechanism 
of the Universe. By R. W. O. Kestel. (Port 
Adelaide, 1898.) 
Tue loose and unscientific use of terms, such as force, 
the curious absence of ordinary mechanical concep- 
tions, as, for example, inertia, and the almost puerile 
objections raised against the Newtonian theory of 
planetary motion, sufficiently proclaim this book to be 
the work of the untrained amateur with original ideas. 
In consequence, none but a discerning reader will 
profit by its perusal. Yet the closing sentence— 
“Radiant Energy is a Working Power in the 
Mechanism of the Universe ’’—is a remarkable one, 
considering that the book is dated as having been pub- 
lished five years ago. The researches of Nichols and 
Hull in America, and Lebedew in Russia, on the 
pressure due to radiation have established the author’s 
contention. In the chapter on comets some of our 
present notions of the cause of comets’ tails are clearly 
anticipated, but in applying the same idea to other 
parts of the mechanism of the universe, the author 
has fallen into the error of imagining a repulsion 
from the sun “just thirty thousand million times too 
large.” The main idea is that ‘‘a repelling force 
radiating from the sun” ‘‘partakes of the sun’s 
motion of rotation,’’ and ‘‘ is carried round in the direc- 
tion the sun is revolving.’’? The author justifies him- 
self by mechanical analogies, and uses the idea to 
account for the origin of both the orbital and axial 
motions of the planets. By the aid of a model in 
which the repulsive force is represented by a stream 
of horizontal water jets emanating from a rotating 
nozzle, many of the phenomena of planetary motion, 
it is claimed, can be demonstrated experimentally. 
The idea, although so crudely expressed, when applied 
to our present knowledge does seem to possess a real 
value. Light, radiating from the sun, should, it 
seems, be affected by the rotation of the sun, in such 
a way that the resultant of the pressures from all parts 
of the solar surface which reach a planet passes 
through a point displaced from the centre in the direc- 
tion of the edge approaching the planet. The same 
would apply to pressure exerted by normally projected 
corpuscles or electrons. The effect is to produce a 
positive acceleration of the planet in its orbit. Whether 
there is also a couple acting to produce rotation 
suggests a nice problem for the astronomer. Is it 
possible that these infinitesimal pressures acting over 
infinite time could originate the motions of the planets ? 
NO. 1779, VOL. 69] 
He | 
| Physikalisch-chemische Theorien. 
| 
| 
| 
Could these pressures maintain the planet in uniform 
motion through a resisting ether? These problems 
should now admit of a definite answer, and seem 
worthy of a more competent analysis than the reviewer 
is able to give. 
Von A. Reychler, 
nach der dritten Auflage des Originals bearbeitet 
von B. Kihn. Pp. xii+380. (Braunschweig : 
Vieweg und Sohn, 1903.) Price 9 marks. 
For its compass this volume contains a wonderful 
amount of well-arranged material. It covers the 
ground usual in elementary works on physical chem- 
istry, but by concise treatment of descriptive and 
theoretical matter the author finds room for much 
detail that has no place in other books of equal size- 
This gives it considerable value as an elementary work 
of reference, whilst it rather detracts from its suit- 
ability to the needs of the beginner. 
What will probably render the book most interesting 
to English readers is the substitution by the author of 
a peculiar hypothesis of hydrolytic dissociation for 
Arrhenius’s hypothesis of electrolytic dissociation, 
which, however, is duly expounded in its place. The 
author conceives that when a salt is dissolved in water 
it dissociates into the corresponding acid and base, the 
degree of dissociation being presumably equal to that 
attributed to the salt by Arrhenius’s theory. The 
behaviour of acids and bases themselves is explained 
by an auxiliary hypothesis which postulates the 
separation from the total solvent water of a special 
kind of water molecule which cannot pass an osmotic 
membrane permeable to the other water molecules. 
Unfortunately the author makes no attempt to carry 
out his theory in detail, and so the reader is left in a 
somewhat dubious state of mind regarding its merits. 
The author reproduces on p. 78 Traube’s erroneous 
deduction of the degree of association of a liquid from 
the results of the volume method. A glance at the 
formula shows that it is only correct when x=1 or 
x=2, and is erroneous for all intermediate values. 
Electrical Engineering Measuring Instruments. By 
G. D. Aspinall Parr. Pp. viii+328. (London: 
Blackie and Son, Ltd., 1903.) Price gs. net. 
Mr. AsPINALL Parr has aimed at giving a description 
of all the leading electrical measuring instruments on 
the market, and he has carried out this object with a 
painstaking thoroughness worthy of a better cause. 
There can be few instruments enjoying any respect- 
able sale which are not included in this book, and the 
descriptions are exceedingly clear; so also are the 
illustrations of the working parts, yet the reader gains 
little more from the book than he could gain, with 
perhaps a trifle more trouble, from a perusal of the 
makers’ catalogues. ‘* Fig. 70,’ to quote from the 
book, ‘‘ shows the general appearance of this instru- 
ment with the index pointer set to to2 and the pointer 
clamped at zero,’’? and Fig. 70—a picture of a brass case 
and a paper scale—is typical of quite 50 per cent. of the 
370. excellently reproduced illustrations. The im- 
portance of instruments to electrical engineers is not 
to be underrated, and it is quite. true, as the author 
says in his preface, that the literature of the subject 
has been neglected. But the literature that is needed 
is not a collation of catalogues, but something that 
may guide the purchaser in selecting an instrument 
suited to his purpose. Mr. Parr makes a point of 
having avoided comparison, yet this is the very thing 
that is wanted; in many cases one can form no idea 
whether the instrument is suited for high or low 
voltages, for large or small currents, what is its 
accuracy under different conditions, or what even is 
the general accuracy obtainable with instruments of a 
