11Q Count Rumford’s Account of some 
well trimmed, in the open air, at mid-day, at a time when the 
ground was deeply covered with new fallen snow, and the 
heavens were overspread with white clouds ; when the flame of 
the candle, far from being white, as it appears to be when 
viewed by night, was evidently of a very decided yellow 
colour, not even approaching to whiteness. The flame of 
an Argand’s lamp, exposed at the same time in the open 
air, appeared to be of the same yellow hue. But the most 
striking manner of shewing the yellow hue of the light 
emitted by lamps and candles, is by exposing them in the 
direct rays of a bright meridian sun. In that situation the 
flame of an Argand’s lamp, burning with its greatest bril- 
liancy, appears in the form of a dead yellow semi-transparent 
smoke. How transcendently pure and inconceivably bright 
the rays of the sun are, when compared to the light of any of 
our artificial illuminators, may be gathered from the result of 
this experiment. 
It appearing to me very probable, that the difference in the 
whiteness of the two kinds of light, which were the subjects 
of the foregoing experiments, might, some how or other, be 
the occasion of the different colours of the shadows, I at- 
tempted to produce the same effects by employing two artifi- 
cial lights of different colours ; and in this I succeeded com- 
pletely. 
In a room previously darkened, the light from two burning 
wax candles being made to fall upon the white paper at a 
proper angle, in order to form two distinct shadows of the cy- 
linder, these shadows were found not to be in the least 
coloured ; but upon interposing a pane of yellow glass, ap- 
proaching to a faint orange colour, before one of the candles. 
