1S80.] Analyses of Books . 469 
in which a fly poisoned on arsenical paper has been burned, a 
very marked difference can be observed between the two, even 
with an ordinary lens.” It is quite possible that the number of 
elements which enter into the systems of plants and animals may 
prove, on careful examination, much more numerous than has 
been hitherto supposed. 
A paragraph headed “ Diamonds, Artificial, to make” is capable 
of being misunderstood. The substance produced, consisting 
exclusively of lime and boric acid, has little chemical analogy 
with the diamond. The author states that he has discovered the 
colouring principle of the sapphire, and can now make stones, 
chiefly of alumina, a deep blue colour without using any colouring 
oxide whatever. What this colouring principle is the reader is 
not informed. 
To those chemists — unfortunately too few, in England at least 
— who study the reactions of substances in the dry way, as well 
as to mineralogists, geologists, mining engineers, &c., this book 
may be safely recommended, and from its portable character it 
will prove a useful travelling companion on exploring expeditions. 
We wish Colonel Ross continued success in that department 
of chemistry to which he has devoted himself with such ardour 
and perseverance, and a wider appreciation than has hitherto 
been his lot. 
Journal of the Society of Telegraph Engineers. Vol. ix., No. 32. 
May, 1880. 
This number contains a summary of the present position of 
eledtric lighting on the Jablochkoff system. The author considers 
that if we take it for granted that the question of eledtric lighting 
does not progress more rapidly than the other great discoveries 
and inventions of the century, one may fairly expedt that it will, 
within a very reasonable time, become of general and every-day 
use. 
The desirability of getting rid of the term “ candle-power,” in 
the measurement of light, was suggested. 
Prof. Hughes read a paper on some effedts produced by the 
immersion of iron and steel wire in acidulated water. Whatever 
the quality of the metal, or the nature and proportions of the 
acid, the wire is rendered brittle, whilst similar treatment pro- 
duces no such effedts upon copper and brass. The author adopts 
the view suggested by Prof. W. Chandler Roberts, that the result 
is due to the absorption of hydrogen. 
