enema 
Hare on the Galvanic Deflagrator. 101 
trough is situated as when not subjected to the acid. In the 
representation of the lower trough, the galvanic series is 
omitted, in order that the interior may be better understood. 
The series belonging to this trough, may be observed be- 
low it, in three boxes, each containing 50 pairs, fig. 2. In 
placing these boxes in the trough, some space is left be- 
tween them and that side of the trough on which the acid 
prevented from touching it by grooved strips of wood. 
Each plate of zinc is soldered to the next case of copper, 
on one side. is may be understood from the diagram, 
fig. 3. It must be observed, that the copper cases are open 
only at the bottom and top. They are separated from 
each other by very thin veneers of wood. 
Fig. 4. represents a smaller trough, differing from the 
others only in length. This I made, with a view to some 
experiments on the comparative power of the galvanic pairs 
of the form of copper cases, with zinc plates, above describ- 
ed, and those made on Cruickshank’s plan, or of the form 
used by Sir H. Davy, in the porcelain troughs. 
epresents a box, containing 100 Cruickshank 
fig. 4, 
ig. 6. represents a box, anniaiing 200 Cruickshank 
plates. This differs from the common Cruickshank trough, 
only, in having the interstices as narrow as those between 
