380 Dr. ingenhousz’s Account of a 
force, by which it propels metallic balls of a conliderablc 
weight. To inveftigate the nature of this awful ingre- 
dient, by which the fate of empires is decided in our 
days, cannot be indifferent to any body who takes de- 
light in inveftigating natural caufes. 
Being at Amfterdam in November 1777, Meflieurs 
aeneae and cuthbertson, two ingenious philofophers 
of that city, were fo good as to fhew me fome curious 
experiments with explofive and inflammable airs of dif- 
ferent kinds. They produced an inflammable air, by 
mixing together equal qualities of oil of vitriol and fpi- 
rit of wine, and applying heat to the phial containing 
the compound. A great quantity of white vapour was 
extricated, which, palling up the inverted receiver filled 
with water, fettled at the top and deprefled the water, as 
other airs do. This air foon became clear, the white 
fumes being abforbed by the water. This air was eafily 
lighted in an open cylindrical glafs, and burnt almoft as 
clear as a candle, the flame defcending gradually lower 
and lower till it reached the bottom. A very little quan- 
tity of this air mixed with common or dephlogifticated 
air, for inftance, one fourteenth or one tenth part, and 
kindled by an electrical fpark, exploded with a very loud 
j eport, and fhattered the glafs to pieces in which it was 
kindled, when it did not find a ready vent. 
They 
