278 Progress in Science. (April, 
V. Form. General tendency of the eye to show ultimate particles circular. 
Effe& of square and triangular apertures. Effect of astigmatism upon form, 
particularly of lines and dots, as seen in different directions. Effects of dif- 
fraction upon points of light, &c. General considerations of the effects of 
unnoticed differences of vision, producing discrepancies often attributed to 
other causes. 
Evectriciry.—T he“ Journal des Debats”’ noticesa very ingenious application 
ofelectricity to voting in the National Assembly. ‘‘ Before every Deputy two ivory 
buttons are placed, like the buttons of eledtric bells. If the Deputy wishes to 
vote ‘ Yes,’ he presses the button on his right; if he wishes to vote ‘ No,’ he 
presses the button on his left. The voter establishes by this means an eledtric 
communication, which is transmitted to an apparatus close to the President 
and his secretaries. Every time the electric current acts thus it opens the 
door to a ball, and the ball falls through a tube into the ballot box. The balls 
are made of glass or ivory, and are strictly identical in weight. The two 
ballot-boxes are then weighed, and the number of balls is indicated by the 
weight. Finally, by turning a handle, all the balls which have not been used 
are let out, and they give the number of members who have abstained, or were 
absent when the vote was taken. Nothing can be more simple. The inventor 
(M. Jacquin) has offered to set up his apparatus in the Versailles Assembly for 
the sum of 60,000 frs. Time is money.” The ‘‘ Debats’’? mentions also 
another plan invented by M. Martin, a well-known eleétrician. M. Martin’s 
plan does away with the scales, which might not always be true. Accordingly, 
as the vote is black, a piece of coloured pasteboard appears instantaneously 
above a line bearing the name of the Deputy. Before each Deputy is a small 
box, supplied with two buttons. When he presses on one or the other, he 
discloses the piece of white or black card on the board. The sum total of the 
votes for either side is marked on a totalising board. The advantage of this 
system over that presented by M. Jacquin is, that it enables the President to 
see whether a Deputy has not voted because he abstained or because he was 
absent. A member can, by placing his hand on both buttons, vote at once 
“Yes” and *‘ No,” and be thus numbered among the abstainers. 
TrcHNOLOGYy.—A recent number of the “ Bulletin of the Industrial Society 
of Mulhouse” brings avery interesting report on ‘‘ The New Dyes of Croissant 
and Bretonniére,” from which we gather that a special committee has been 
investigating them in order to ascertain their value for the various purposes of 
dyeing and printing. At first the great durability of these colours engaged the 
attention of the members of the committee. Ink spots could, for instance, 
readily be removed by means of oxalic acid without the dyes themselves being 
changed in the least. The sunlight, as far as observations go, seems not to 
exert any influence on these colours ; boiling soap-solution and oxalic acid are 
without effeé, only chlorine or hypochlorites affect or rather destroy them. 
In a paper on ‘Certain Properties of Weighted Black Silks” M. J. Persoz 
shows that weighting—which began with the modest aim of making up the loss 
sustained in ungumming—is now carried to the extent of 100, 200, and 300 per 
cent. This increase of weight is produced by treatment with salts of iron and 
astringents, salts of tin and cyanides. The bulk is augmented proportionably 
to the weight. As a matter of course, the chemical and physical properties of 
the silk thus treated are materially modified. What is sold as silk is, in fact, 
a mere agglomeration of heterogeneous matters, devoid of cohesion, held 
temporarily together by a small portion of silk. The elasticity and tenacity of 
the fibre are sensibly reduced. From being in its natural state one of the most 
permanent of organic bodies, and sparingly combustible, it burns like tinder if 
touched with flame. It is, moreover, liable to undergo spontaneous decompo- 
sition, and to absorb gases with the evolution of heat, which sometimes leads 
to a@tual combustion. The adulterated silk when burning scarcely gives off the 
characteristic odour of animal matter. It leaves an ash of oxide of iron 
exceeding 8 per cent. 
ErratTa.—Page 145, line 18 from top, for ‘‘ Iceland,” read “Ireland.” Page 
148, line 4 from top, for ‘“‘ marked,” read “ masked.” Page 155, line 20 from 
top, for ‘founded on a sound data,” read “ founded on sound data.” 
