_ Miscellaneous Intelligence. 44] 
Elysées, towards the Place de la Concorde, and a second on the avenues of 
Neuilly or de I’Impératrice, the change having been made because of the 
numerous gas lights of the Champs Elysées. -These gas lights were made 
to look dull and smoky, yet diminished the effect of the electric light ; 
but in the avenues of J’Impératrice the light presented intense brilliancy. 
h lamp was sustained by means of sixty of Bunsen’s pairs, and fur- 
nished with a spherical reflector of metal, or of glass silvered by a battery 
in the manner describe yond. 
2. New Battery with a constant current.—For some time a battery has 
been known having an improvement for economizing the residues. It 
Was invented by Mr. Doat, an amateur of Alby (Department of Tarn). 
In this battery, the zine is replaced by mercury, the acidulated water by 
iodid of potassium ; the nitric acid or sulphate of copper of the batteries 
With two liquids, by iodine dissolved in the iodid of potassium, and which, 
put in to excess in the solid state, serves to maintain constant action. 
Carbon is employed as the negative pole. A square trough of gutta per- 
cha contains the mereury and the alkaline iodid. The carbon and the 
iodized iodid are put in a square porous cup which is immersed in the 
liquid of the trough to two centimeters above the level of the mercury. 
This battery once in action, requires no other care than that of draw- 
ing off with a glass siphon the liquid saturated with iodid of mercury, 
trough of about five decimeters square, and with a thickness tor the bed 
of iodid of potassium of about three centimeters, it was equivalent to ten 
The process adopted by Mr. Doat for economizing the residues admit- 
On the flat carbon pole, there is placed a 
Containing hydrated carbonate of copper. pega prea 
for a while in action, the liquid, consisting of double iodi gare 
Potassium, is drawn from the tro and thrown upon. the | ter, W -_ 
SECOND SERIES, VOL. XXIII, NO. 69.-—-MAY, 1857. 
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