438 Chronicles of Science. i [ July, 
be made of large dimensions, and a great deal of electricity obtained 
at small cost. 
M. Torreggiani has also described a new battery and a practical 
application of it. Atter repeated experiments, he has proved that a 
pile in which the positive pole is represented by metallic lead, and 
the negative by carbon, and containing a saline solution (an alka- 
line acetate), gives, besides electricity, a large quantity of pure car- 
bonate of lead, which may be profitably employed. The author 
considers that this is an easy and innocuous way of making white 
lead. 
All discoveries in electricity which have been made for many years 
have been surpassed in practical importance by one, the particulars of 
which were communicated to the Royal Society a few weeks ago by 
H. Wilde, Esq. Space will not permit of our giving more than a 
brief account of this invention; but in our next issue, we propose 
to lay before our readers a full account of his entirely new magneto- 
electric machine. The principle is not difficult to understand. An 
armature wound round with insulated wire is made to reyolve rapidly 
in front of the poles of a large permanent magnet. The currents of 
electricity thus induced in the insulated wire are carried round a large 
electro-magnet, which is thereby excited to a very high degree. In 
front of this electro-magnet a second covered armature is rotated, 
and the electric current thus generated is carried round a third 
electro-magnet. It is from a rotating armature in front of this 
third magnet that the electric current ultimately used for heating 
or lighting effects is produced. At each passage round the electro- 
magnets, and induction in the rotating armatures, the electric cur- 
rent becomes magnified to an extraordinary degree, until ultimately 
it is powerful enough to melt iron bars in a minute or two, and to 
produce a light surpassing that of the sun itself. 
The machine is driven by means of a steam-engine, and as 
almost the only current expense is for motive power, it is not an im- 
probable supposition that ere long electric lights of the most intense 
description will be as common in large factories and public build- 
ings as gaslights are at the present time. 
X. ZOOLOGY AND ANIMAL PHYSIOLOGY. 
(Including the Proceedings of the Zoological Society.) 
Erxnotocy or Anthropology is one of those studies which are as yet 
in a very infantile condition, and those who pursue it have to content 
themselves with the accumulation of facts, waiting the time when their 
material may justify the establishment of those broad generalizations 
