122 Morey on Heat and Light. 
bustion still continues, is certain, from the explosive deto- 
gating noise or report, continuing to be distinctly heard. 
Orford, May 4th, 1819. 
Arr. XII. On Heat and Eight; by Mr. Samuet Morey. 
[Second Communication. ] 
TO PROFESSOR SILLIMAN. 
Ss UW's 
As the use of a certain proportion of water for affording 
heat and light, has become more familiar, and some of the 
experiments being very simple, and such as may be easily 
repeated, I have thought I might be justified in submitting 
to your perusal some further remarks and experiments on 
that subject; hopmg you may there from select something 
which may find a place in the American Journal. 
I find, that, for common use, the most convenient mode is 
to evaporate the substance designed to afford light, or light 
and heat, provided it naturally contains a sufficiency of water 
to make the vapor burn with a white flame free from smoke ; 
or if not to furnish the supply by a small separate boiler :-— 
depending on the decomposition of the water in burning 
the vapor, to free it from smoke, as well as to increase the 
intensity of the light. This mode of furnishing light and 
heat for common uses, has many advantages, it appears to 
me, over that of forming and burning gas, some of which 
will be hereafter mentioned. 
If we observe mineral coal when the fire first reaches it, 
we shall perceive, that the vapor which first issues, burns 
with a white flame, free from smoke; owing undoubtedly 
to the great proportion of water. So also it is with pitch- 
pine wood, or the fat knots, if the heat be not too great. It 
is curious to observe the effect in burning any kind of pine 
wood, which contains more or less of these knots. The — 
streams of vapor are often pushed out to a considerable dis- 
tance, and burn with a very pleasant white flame. ‘These 
knots burn for a long time, and will sometimes retain water 
enough to burn the vapor without smoke, until the whole of 
