330 = Account of a new inflammable Air Lamp. ° 
Art. XIX. Account of a new inflammable Air Lamp, by 
Professor Jacop Green, of Nassau Hall. 
TO PROFESSOR SILLIMAN. 
Princeton, Feb. 11th, 1820. 
Dear Sir, 
The great facility with which hydrogen gas may be in- 
flamed by even a moderate electric spark, suggested to 
Volta his inflammable air lamp. This, with a slight altera- 
iion, was patented, as a source of instantaneous light; and 
ts usually found among the electrical apparatus of every 
person who has a taste for philosophical experiments.— 
One inconvenience attending the use of this ingenious con- 
trivance, was, that the reservoir containing the hydrogen 
gas soon became expended, and could not, without some 
trouble, be replenished. Gay Lussac, however, not very 
long ago, removed this defect by suspending a bar of zinc 
in the apparatus, so as to produce by a sort of self-actron, as 
much gas as was exhausted. ‘There is another fault which 
has not,been so happily removed; the electrophorus which 
is connected with this instrument, is, like all other electrical 
machines, so influenced in its action by the state of the 
weather, that there are some seasons when the smallest 
spark cannot be obtained. It has been my object in the 
little contrivance described in this communication, to point 
out a way in which electrical fire may be obtained, inde- 
pendent of the state of the atmosphere. 
Description. 
(See the plate at the end of the volume.) 
A. B. C. D. is a square box, of mahogany, made per- 
fectly air tight. At A. and C. small brass cocks are serew- 
ed into it, so as to form a communication with the inside. 
E. is a glass tube, open at both ends, passing through the 
top of the box, and extending within a short distance of the 
bottom. K. L. isa glass jar, with an open mouth P. such 
as ig commonly used for collecting gases. R.S. isa piece 
@ 
