422 » Hare’s Calorimotor. 
the zinc plates. On each of the approaching terminations of 
the connecting tin strata was soldered a kind of forceps, 
formed of a bent piece of sheet brass, furnished with a screw 
for pressing the jaws together. The distance between the 
different forceps was about two inches. The advantage of a 
yery close contact was made very evident by the action of 
screws; the relaxation or increase of pressure on the con- 
necting wire by turning them being productive of a corres- 
pondent change in the intensity of ignition. 
t now remains to state, that by means of iron ignited in 
"this apparatus, a fixed alkali may be decomposed extempo- 
raneously.* If aconnecting iron wire, while in combustion, 
‘be touched by the hydrate of potash, the evolution of potas- 
sium is demonstrated by a rose-colored flame. he alkali 
may be applied to the wire in small pieces ina flat hook of 
sheet iron. But the best mode of application is by meaus of a 
tray made by doubling a slip of sheet iron at the ends, and 
leaving a receptacle in the centre, in which the potash may 
be placed covered with filings. ‘This tray being substituted 
for the connecting wire, as soon as the immersion of the 
apparatus causes the metal to burn, the rose-colored flame 
appears, and if the residuum left in the sheet iron be after- 
ward thrown into water, an effervescence sometimes ensues. 
I have ascertained that an iron heated to combustion, by @ 
blacksmith’s forged fire, will cause the decomposition of the 
hydrate of potash. 
‘The dimensions of the Calorimotor may be much reduced 
without proportionally diminishing the effect. I have one of 
sixty plates within a cubic foot, which burns off No. 16, iron 
wire. A good workmen could get 120 plates of a foot square 
within a hollow cube of a size no larger. But the inflamma- 
tion of the hydrogen which give so much splendor to the 
bo el can only be exhibited advantageously on a large 
scale. 
* This evidently differs from the common mode of decomposing the fixed al- 
espe by galvanism: there the effect depends on electrical attractions and re- 
Pp here on the chemical agency of ignited iron produced extemporane- 
. ously in the galvanic cireuit: this mode of operating appears ie be new.—Ed. 
