SCIENTIFIC SUMMARY. 
445 
character with the continuous discharge of a voltaic battery. The form 
and positions of the strite appear to depend upon the power of the battery, 
and upon the state of tension of the rarefied gases. The number of striae 
appears to indicate the degree of tension in a closed battery circuit, as 
a gold-leaf electroscope does in an unclosed circuit, and can be regulated 
by introducing different amounts of resistance into the circuit. The number 
of striae decreased as the amount of resistance introduced into the circuit 
was increased ; but at the same time the striae assumed a different shape, 
and the bright and dark portions at the tube occupied different positions. 
Reitlinger has put forward a new explanation of stratified electric light, 
as seen in rarefied media. He supposes that in a tube filled with rarefied 
aqueous vapour, the hydrogen and oxygen are disposed in alternate 
layers, and that the oxygen being a worse conductor of electricity than 
hydrogen, becomes much more heated, and thereby much more luminous, 
and thus produces dark and bright bands. In support of this view, he 
states — 1st, that no stratification has been produced by elementary and 
unmixed gas ; and 2nd, that the vapour of mercury alone gives only a 
white light, without stratification, but immediately on adding a few 
bubbles of air to it, dark bands appear. 
An abstract of a paper, “On the Long Spectrum of Electric Light,” 
read before the Royal Society, by Professor G. G. Stokes, F.R.S., has been 
published in the Proceedings of the Royal Society. He employed as the 
source of light the spark of an induction coil, with a Leyden jar connected 
with the secondary terminals ; and examined the light evolved by elec- 
trodes of different metals. He found light from aluminium electrodes the 
richest in invisible rays of extreme refrangibility, and therefore used that 
metal when examining the behavour of those particular rayt. This 
portion of the spectra of the metals may be viewed by means of fluore- 
scence, and its mode of absorption by different liquids also observed by 
the same means. He finds that solutions of alkaloids and glucosides are 
usually very opaque to those rays, and some of them produce bands of 
maximum opacity in particular parts, highly distinctive of the special 
substance under examination. In natural crystals of adullaria and 
felspar, generally a strong fluorescence is produced by these invisible and 
highly refrangible rays. A particular variety of fluor-spar shows a 
decided reddish fluorescence under the exclusive influence of rays of the 
very greatest refrangibility, and will therefore form a valuable means of 
detecting those rays. 
In the “American Journal of Science and Arts,” January, 1863, 
is a paper, “ On the Equivalent and Spectrum of Csesium,” by S. W. 
Johnson and 0. I). Allen. It professes to contain a more extended 
description of the lines composing the csesium spectrum than that given 
by Kirchoff and Bunsen, and states that it is the most beautiful of all the 
spectra of the alkali and earth metals. 
M. Janssen has described in the Comptes Rendus some new spectro- 
scopes : the first is one with direct vision, it unites great dispersive power 
with simplicity of construction, and seems well adapted for optico-chemical 
analysis; the second is a pocket instrument, forming a small folding glass, 
and is also adapted for direct vision, by means of it the solar spectrum can 
VOL. II. — NO. VII. 2 H 
