426 
POPULAR SCIENCE REVIEW. 
Vital Moveynents and Electricity. — This subject was part of that of a paper 
by Dr. C. B. Radcliffe, read before the British Association. The’ paper was 
entitled, a Whether the Causes of Vital Movement are yet clearly Appre- 
ciated.” The paper commenced with a resume of the opinions of ancient and 
modern writers on the subject of vital movement. He ridiculed the current 
doctrine which, he said, assumes that vital movements are distinct from 
those manifested in inert matter, and which can at best be only regarded as 
a hasty deduction from superficial observations. The highest aspirations 
of philosophy, he contended, are in direct contradiction to this assumption : 
and the doctrine of the correlation of physical and vital forces implies a 
grand centralisation, by which what have been regarded as separate forces 
are made to appear as various aspects of some central force. Dr. Radcliffe 
then referred to some investigations which he had recently made with Sir 
William Thompson’s electrometer, and which had tended to confirm the 
views of Galvani. He mentioned, by way of illustration, a singular ex- 
periment that he had made with a strip of india-rubber, coated on the two 
surfaces with metal, which was elongated by the attraction of two opposite 
charges ; the discharge causing the india-rubber to contract to its original 
length. 
MICROSCOPY. 
A valuable Table of Objectives has been published in the u Monthly Mi- 
croscopical Journal ” (August). This Table, by Dr. R. H. Ward, is designed 
to be complete in regard to American lenses, and to present for comparison, 
and for the convenience of those who desire a variety of lenses by different 
makers, such European items as could be obtained at the time of writing. 
It is believed that the Table will be interesting to others than buyers, 
as showing the prevailing powers, prices, angular apertures, &c., in 
different parts of the world. Notwithstanding the general impression, that 
the prices of American objectives are unreasonably high, it will be seen 
that they compare favourably with those of the most celebrated English 
makers. Most opticians prepare, very cheaply, mounted objectives of small 
angle, and usually second quality, which answer a good purpose where 
economy is imperative and difficult work is not required. Such lenses are 
not usually priced and sold separately by the American makers, and are 
therefore not included in their columns in the “ Table of Objectives.” 
They can be obtained, however, at prices proportioned to theirTangles and 
quality. The prices and angular apertures given in the Table are 
generally, though not in every case, official and up to date j but a reason- 
able allowance must be made for practical variation from the standard 
angles and powers. There is understood to be a screw-collar adjustment 
for all objectives of over 50° angular aperture, unless otherwise stated; 
though, from want of sufficiently distinct description by their makers, this 
rule cannot be applied to some of the English lenses of medium power and 
small angle. To persons without great experience in microscopy, the best 
u test ” of an objective is the respectability of its maker. 
The Sturgeon's Development. — The Acclimatisation Society of Paris lately 
