422 
hope to see them deeply impressed on the public 
mind. 
The instructive descriptions before us are accom- 
panied by excellent figures; nevertheless we have 
a suggestion to make about the determination of 
the house-flies. Dr. Graham-Smith has eighteen 
species of house-frequenting Diptera to deal with 
(p. 15). Most of them present no serious diff- 
culty, but students unpractised in entomology will 
find a few hard to distinguish. Would it not be 
well to lighten their labours by a discrimination- 
table, which would concentrate attention upon the 
decisive characters? A single character (e.g. the 
tubercle on the middle tibia of Fannia scalaris), is 
sometimes a certain mark of the species. Or the 
really decisive characters might be italicised. The 
student should afterwards compare his fly with 
the description in every point; identification is 
not the only purpose of descriptions. 
Non-piercing strikes us as a neater phrase than 
non-bloodsucking. 
The Ideals and Organisation of a Medical Society. 
By Dr, J. B. Hurry. “Pp. 51. (Mondon: J, 
and A. Churchill, 1913.) Price 2s. net. 
THE name of Reading, at the present moment, 
is mostly associated with political excitement; 
but Reading has many interests, and, among 
them, it is the home of one of the best of all the 
provincial medical societies. Dr. Hurry has done 
well to write an account of the work, purposes, 
and constitution of a medical society. He is a 
good friend to Reading; he loves its history, its 
old buildings; he has made many gifts to the 
town; he has been, for years, its chief chronicler; 
and the Reading Pathological Society is an 
example of all that a medical society ought to be. 
Indeed, a good medical society is a very great 
help to a town. It raises the level of things; it 
promotes the spirit of science; it ensures the 
efficiency of the town’s hospital; it is a bond of 
union among’ practitioners; it adds dignity, dis- 
tinction, and modernity to their art, and friend- 
ship and ambition. The interchange of know- 
ledge, the comparison of experiences, the criti- 
cism, the honourable competition, all tend to 
achievement. Of course, there are difficulties; 
the hard-worked doctor cannot easily find time 
to attend meetings or to prepare papers. Waste 
of time, repetition, overlapping of subjects, are 
to be avoided, but are not always easy of avoid- 
ance. But a good medical society, such as the 
Reading Pathological Society, is an excellent help 
to men in practice, and to the town in which they 
practise. 
A Day in the Moon. By the Abbé Th. Moreux. 
Pp. vili+199. (London: Hutchinson and Co., 
1913.) Price 3s. 6d. net. 
Ix these pages the Abbé Moreux chats on the 
moon and all that is related to it, and the reader 
will find not only that the matter is displayed in 
a very readable form, but that he will have learnt 
numerous facts, and have had a very instructive 
lesson, by the time he has finished the volume. A 
NO. 2302, VOL. 92] 
NATURE 
[DECEMBER II, I913 
day in the moon refers actually to a lunar day, and 
the reader is transported to the moon and treated — 
as if he were an inhabitant of that body. The 
author in this way introduces him to the mountain 
ranges and craters, and other conspicuous high | 
and low lands which are brought into view as the 
solar rays illuminate them. Here and there are 
brought in incidentally interesting side issues, 
such as the probable use of lenses before ever 
Galileo or the inventor, a certain Dutchman, came 
to re-invent and use them. Bringing the reader 
back to earth again, he introduces him to such 
themes as the tides, possible weather changes due 
to the moon, action of the moon on vegetation and 
organic life, and on men and animals, and finally 
concludes with a list of objects shown on a map of 
the moon, those to be studied on each day of a 
lunation, and the lunar elements. Numerous illus- 
trations from photographs and the author’s draw- 
ings accompany the text. The translator has done 
his work well, and has, in the form of footnotes, 
made many statements more clear to British 
readers, such as when references were made to the 
metric system of measurements, and to distances 
between French towns. 
Recent Physical Research. An Account of some 
Recent Contributions to Experimental Physics. 
By D. Owen. Pp. iii+156. (London: The 
Electrician Printing and Publishing Co., Ltd., 
Meds), Price 35. 6d, snet- 
A PUBLICATION dealing with some of the most 
important recent developments of physics is sure 
to be of use if written with sufficient knowledge 
and a pleasing style. This book has both those 
advantages. The subjects include positive rays 
(with Thomson’s new method of chemical 
analysis), the magnetic work of Curie, Weiss, 
and Heusler, new theories of the aurora (Stérmer 
and Birkeland), Brownian movements (Einstein 
and Perrin), the pressure of light, the narrowing 
gap between the longest heat-waves and the 
shortest electromagnetic waves (Rubens, Lebedef), 
and the application of the electron theory to 
metallic conduction. The blocks are particularly 
good. One could wish for rather fuller refer- 
ences, and for a fuller treatment of the modern 
radiation problem (on p. 106 Planck’s and Wien’s 
formule are presented without directing attention 
to the importance of the “action constant”). But 
in view of the limited space at the author’s dis- 
posal, a large amount of new information is 
attractively displayed. : 
Lip-reading: Principles and Practice. A Hand- 
book for Teachers and for Self-instruction. By 
Edward B. Nitchie. Pp. xiv+324. (London: 
Methuen and Co., Ltd., n.d.) Price 5s. net. 
Tue hard-of-hearing will be able to study lip- 
reading from this book without the aid of a 
teacher, if such a course is found necessary. The 
book is arranged also for use, under a teacher’s 
guidance, by the semi-mute and the congenitally 
deaf who have acquired speech and language. 
The first part of the book is explanatory and direc- 
tive, and the second gives exercises for practice. 
