1874.] Notices of Books. 117 
The concluding section, on the methods of observing and 
detecting ozone in the atmosphere in the air, is without doubt 
the most interesting and valuable. The author concludes that 
iodised litmus and simple iodide of potassium are the only tests 
that can be considered trustworthy. For the precautions to be 
observed in their employment we must refer to the book itself. 
We are bound to declare that, in our conviction, Dr. Fox has 
merited well at the hands of the scientific public for the elaborate 
and well-arranged digest of facts which he has placed at their 
disposal, and we join him in the hope that his labours will furnish 
a sound basis for future investigations. 
Elementary Treatise on Physics, Experimental and Applied, for 
the Use of Colleges and Schools. ‘Translated and Edited 
from Ganot’s ‘“‘ Eléments de Physique.” By E. ATKINson, 
Ph:D:, F.C.S., Professor of Experimental Science, Staff 
College, Sandhurst. Sixth Edition, revised and enlarged. 
London: Longmans and Co. 1873. 
THE most prominent enlargements to this edition consist in further 
elucidation of the laws of the polarisation of light, a description 
of Gramme’s continuous magneto-electric generator, and a 
further development of the theory of heat as recently advanced. 
We are glad also to notice an extension of fundamental formule. 
Nothing need be said in further praise of so eminently a standard 
work. 
A Treatise of Medical Electricity, Theoretical and Practical ; 
and its Use in the Treatment of Paralysis, Neuralgia, and 
other Diseases. By Jurius’Artuaus, M.D., M.R.C.P: 
Lond. Third Edition, enlarged and revised, with 147 
illustrations. London: Longmans, Green, and Co. 1873. 
In religious dogma everyone knows the old saying that described 
orthodoxy as ‘my own peculiar doxy,” and heterodoxy as 
“‘everybody else’s doxy.” But dogma (taken in its sense of 
enforced opinion) is not peculiar to religious discussion ; the next 
elder science, that of medicine, has been full of it from the days 
of Asculapius and Galen till now. Even now we are not free 
from the error of recording opinion instead of fact. And such 
a view is impressed upon all students of electro-medical 
science. The opinions held in contrast with the facts ascertained 
and stated without bias, are in overwhelming proportion. Indeed, 
the proportion is so great, that the influence of error is per- 
ceptible upon the minds of the public, who are too apt, perhaps, 
to regard electro-medical practitioners with not a little undue 
severity. It is then the duty of a scientific serial to uphold the 
careful chronicle of facts, and discourage the register of mere 
opinion, founded, if of any foundation, upon incomplete observa- 
tion of fact. Thus it is our duty to commend to those who may 
be about to become interested in electro-medical science the 
