Properties of Wood Ashes. ‘87 
stirred in a large quantity of water, and allowed to subside. Ina 
short time the insoluble parts settled at the bottom, and most of 
the coal with them, very few particles of it floating on the water. 
Hence the porosity of the coal must have been sufficiently de- 
stroyed to render the fragments specifically heavier than this fluid. 
3. The washed ashes used in the foregoing experiments, were 
examined by a microscope, and particles of coal clearly*seen in 
them. Specimens of well burnt and sifted ashes from the stove, 
exhibited the same appearance. 4. Several hundred grains of 
sifted ashes were treated with nitric acid, and after long diges- 
tion, the residue was washed, dried, and weighed ; the quantity 
was six per cent. of the original weight of the ashes. Under the 
microscope this residue was found to consist of particles of coal, 
@ greater proportion of black vitrified grains, and transparent par- 
ticles which scratched glass, and appeared to have undergone par- 
tial fusion. 5. One hundred grains of sifted ashes were in like 
mannér submitted to the action of hydrochloric acid. On dilu- 
ting the solution with water, a black matter was immediately 
deposited with gray particles beneath it. The black sediment, 
washed and dried, assumed a black-brown color, and weighed a 
fraction over six grains. This powder scintillated in the blaze of 
a candle like coal-dust; under the action of the blowpipe it be- 
came gray, but the principal part remained unconsumed. 
Having by these means convinced myself of the presence of 
coal-dust in ashes, it followed that an ordinary fire did not always 
consume all the carbon of wood; and to arrive at an approxima- 
tion to the degree of heat Hecestery nesbinty: it out of ashes, I 
tried the next experiments. 6. Sifted ashes were pressed firmly 
into a crucible, and to expel moisture I subjected them to a tem- 
perature of at least 440° for an hour. ‘The temperature was as- 
certained by the fusion of tin. The ashes were then weighed, 
and subjected toa red heat for half an hour. On weighing again, 
there was no appreciable loss. Sulphuric acid and the micro- 
seope’detected, as before, particles of coal in these crucibulated 
ashes. 7. Most of the ashes of the last experiment were placed 
loosely in the crucible, and again heated to redness for a an 
hour. The result was as before—no loss of weight. 
mately mixing thirteen grains of coal-dust with four hundred ar” 
sixty seven grains of the erucibulated ashes of the seventh ex- 
her, poe: were heated to red- 
: Sy a 7 
