120 Morey on Heat and Light. - 
Again, if water in one cylinder be made to boil, and the 
steam be led to the bottom of another included cylinder, 
containing spirits of turpentine, the steam, when let out un- 
der a moderate pressure, carries off with it a sufficient quan- 
tity of the spirit to burn with a pleasant white flame, free 
from smoke ; by increasing the pressure, the flame will be- 
come in part or wholly blue. Here as in many other ex- 
periments, I have noticed, that different coloured flames 
may be produced from the same materials—are the products 
of the combustion different ? 
If the steam of water, containing a small proportion of the 
vapour of rosin be driven against iron, at or below a red 
heat, it burns with a pleasant blue flame, which will be ex- 
tended some way back into the column of the vapour, inter- 
mixed with innumerable sparks of very white flame, evi- 
dently particles of the rosin. 
If the vapours, when the proportion of rosin is very small, 
are made to pass between two plates of iron, at or near a 
red heat, they can be inflamed on the opposite sides of 
the plates, and will then, sometimes, burn with an entirely 
blue flame, although the vapour cannot be inflamed, with- 
out the intervention of the plates. 
If the steam of boiling water, be led to the bottom and 
passed up through tallow at a high temperature, and then 
through cold water to condense the vapour, the hardened 
tallow will float on the surface : and on applying a flame, it 
would sometimes, take fire, some distance before the flame 
reached it, at other times it would require, to be in contact 
a few seconds, always beginning to burn with a blue flame, 
and after the whole surface had been sometime enveloped 
in flame, and the heat was such, against one side of the top 
or rim of the vessel, as to cause the water below the oil on 
that side to boil, and pass up through the oil, the flame on 
this side would be chiefly blue. Does not this show that the 
steam was on this side decomposed in passing through the 
inflamed tallow, and from its sometimes taking fire on the 
approach ofa flame, it would appear clearly that there was 
an evaporation of hydrogen, from the tallow, and when 
burnt with the same sized wick, it appeared to me to give 
three or four times as much light as other tallow, which 
pointed out as I thought, that it was rendered in the process 
highly combustible. 
