290 Dr, Hare’s Description of Voltaic Series, &c. 
end of each of the lead rods is soldered to a piece of sheet copper. 
The pieces of copper, thus soldered to the lead rods, are then to be 
placed under the pivots, which are of course to be connected with 
the termination of the series. The last mentioned connexion is 
conveniently made by means of straps of copper, severally soldered 
to the pivots and the poles of the series, and screwed together by a 
hand-vice. Each pair consists of a copper and a zinc plate, united 
by solder at the upper edge, where the copper is made to embrace 
the edge of the zinc. The three remaining edges are made to enter 
grooves in the wood, being secured therein by cement. For each 
inch in the length of the trough there are three: pairs. In the series 
represented by fig. 1, there are one hundred pairs of fourteen inches 
by eight; in that represented by fig. 2, there are seven hundred 
pairs of seven inches by three. The latter will deflagrate wires too 
large to be ignited by the other, but is less powefful in producing a 
Jet of flame between the charcoal points, or in giving a shock. 
Fig. 2, on the opposite page, represents a series which comprises 
two Cruickshank deflagrators, so constructed as to co-operate in one 
circuit by an adequate communication between their poles, and be- 
ing so associated with a lever,-as to be made, by means of it, to re- 
volve simultaneously. They may be made to act either collaterally, 
as a series of 350 pairs, or consecutively, as 700. As the plates are 
seven inches by three, when used collaterally, they are equivalent to 
350 plates of seven inches by six. 
Combustion of Phosphorus in nitrous oxide gas.* 
There is a striking backwardness in the oxides of nitrogen to part 
with their oxygen to phosphorus, until it be intensely ignited, either 
by an incandescent iron, or by the access of uncombined oxygen. 
This characteristic in the case of nitrous oxide, may be illustrated 
by means of an apparatus like that employed for the combustion of 
phosphorus in oxygen with a tall cylindrical receiver, and a tube de- 
scending through the neck, and along the axis of the receiver, termi- 
nating in a capillary orifice over the cup for holding the phosphorus. 
The upper end of the tube, outside the receiver, is furnished with a 
cock, to which a gum-elastic bag inflated with oxygen is attached. 
Under these circumstances, the receiver having been exhausted, 
and filled with nitrous oxide ; phosphorus, previously placed within 
the cup, may be melted without taking fire. But as soon as the cock 
tha ae: 
* An apparatus employed by Dr. Hare for exhibiting the same peculiarity in 
Pe aes Po ee a 4 ne hlished in this Tournal,. 
ALLOGUY P 
