im 
On Spontaneous Inflammations . 
gave a thick, grey, stinking smoke. Mr. Georgi took the 
bundle out of the chest, and laid it on a stone pavement ; 
when, on being exposed to the free air, there arose a slow 
burning flame, a span high, with a strong body of smoke* 
Not long afterwards there appeared, here and there, se- 
veral chaps, or clefts, as from a little volcano, the vapour 
issuing from which burst into flame. On his breaking the 
lump, it burst into a very violent flame, full three feet 
high, which soon grew less, and then went out. The 
smoking and glowing fire lasted for the space of six 
hours ; and afterwards the remainder continued to glow 
without smoke for two hours longer. The grey earthy 
ashes, when cold, weighed about five ounces and a half. 
In another experiment, perfectly similar to the forego- 
ing, as far as relates to the composition and quantities, 
the enkindling did not ensue till forty -one hours after the 
impregnation : the heat kept increasing for three hours, 
and then the accension followed. 
It is worthy of remark, that these experiments succeed- 
ed better on bright days than on such as were rainy ; and 
the accension came on more rapidly. 
In another experiment, three pounds of Russian fir- 
black were slowly impregnated with three pounds of raw 
hemp-oil $ and the accension ensued after nine hours. 
Three quarters of a pound of German rahm were slow- 
ly impregnated with a pound and a half of hemp-oil var- 
nish. The mixture remained seventy hours before it be- 
came hot and reeking. It then gradually became hotter, 
and emitted a strong exhalation ; the effluvia were moist, 
and not inflammable. The re-action lasted thirty-six 
hours, during which the heat was one while stronger, and 
then weaker, and at length quite ceased. 
Stove or chimney soot, mostly formed from birch-wood 
smoke, was mingled with the above-mentioned sub- 
