Galvanic Batteries. 171 
which both the trough containing the plates and another trough to 
collect and hold the liquid are fixed. ‘This arrangement I have fou 
the most convenient of any, and have therefore adopted it.” 
Here follows an engraving and description of the deflagrator which 
the celebrated author constructed agreeably to the principles of Dr. 
Hare’s, after which he proceeds to say— 
‘Such was the facility afforded by this arrangement, that a trough 
of forty pairs of plates could be unpacked in five minutes, and re- 
packed again in half an hour; and the whole series was not more 
than fifteen inches in length. 
“This trough of forty pairs of plates three inches square was com- 
pared as to the ignition of a platina wire, the discharge between points 
of charcoal, the shock on the human frame, &c., with forty pairs of 
four-inch plates having double coppers, and used in porcelain troughs 
divided into insulating cells, the strength of the acid employed to ex- 
cite both being the same. In all these effects the former appeared 
quite equal to the Jatter. On comparing a second trough of the new 
construction containing twenty pairs of four-inch plates with twenty 
irs of four-inch plates in porcelain troughs, excited by acids of the 
same strength; the new trough appeared to surpass the old-one in 
producing these effects, especially in the ignition of wire.” 
We omit here a detail of the ingenious and accurate experiments 
on which Mr. Faraday’s inferences were founded, our object being 
in this article to quote his conclusions, rather than his premises ; and 
shall accordingly pass on to those portions of his paper in which the 
former are communicated. 
‘‘ When ten pairs of the new arrangement were used, the consump- 
tion of zine at each plate was 6.76 equivalents, or 67.6 for the whole. 
With ten pairs of the common construction, ina porcelain trough, 
the zinc oxidized was, upon an average, 15.5 equivalents each plate, 
or 155 for the entire trough 
and it is that circumstance which principally permits of such other 
alterations in the construction of the trough as gives it its practical 
advantages. 
‘The advantages of this form of trough are very numerous and 
Ist. It is exceedingly compact, for one hundred pairs of plates 
h of more than three feet in length. 
ereury, d in the front of the stand of the instrument, These 
fixed terminations give the great advantage of arranging an apparatus 
