LN aT ae ee 
vic Acid — Wells. 165 
| XIX, —On the Feed of Carbonic Acid Gas from 
Wells, Sc., and Spontaneous Combustion in Wood Ashes ; by 
Otiver P. Hessarp, M. D., Prof. of Chem., Min. and Geol. in 
Dartmouth College. 
Combustibility of Wood Ashes; by Dr. Joun 'T. Pruner, = 
- Richmond, Indiana. 
“Tne following verbal statement I received fom T Dr. 8. E. Hale, 
a graduate of the Medical School of Dartmouth College. While a 
student at Burlington, Vt., a deep well in the yard of the stable 
connected with the hotel was to be cleaned. A man was about 
to descend for this purpose, but, at the suggestion of Mr. Hale, 
waited till he could test the well for carbonic acid gas. A light- 
ed candle was adjusted, and on lowering it with a.cord, it was 
extinguished at ‘he very mouth of the well. He then applied the 
remedy, ignited charcoal, as recommended by me in this Journal, 
(Vol. xxxvi, p. 206,) and entirely removed the gas, so that the 
candle burned clearly in every part above the water, which was 
some twenty or more feet from the surface of the ground; and 
the man descended with impunity and accomplished his object. | 
This well was situated at nearly the lowest part of the yard, and 
in the vicinity of abundant sources of carbonic acid from the de- 
composition of animal manures, and may be a constant reservoir 
for the accumulation of the gas. Though this be a strong case, 
ret in all cases the successful. use of the charcoal once should 
not prevent its repeated BEES, even at short intervals, if oc- 
casion required. 
-1,. Spontaneous Combustion in Wood Ashes.—In September, 
1840, my attention was called by a soap-boiler, who was re- 
moving ashes from a brick arch in my cellar, to a remarkable 
phenomenon he had just observed in the ashes in his cart he 
had last brought out. I applied my hand to a spot as directed, 
and found the heat so great I could hold it there but a moment 
at atime; and on examination of the ashes in the arch from 
which these last had been taken, I found the same heat limited 
‘to asmall area in the centre of the bottom, which was now cov- 
ered by a small quantity of ashes remaining, from twelve to four- 
teen. bushels. ‘The ashes formed a heap two feet thick on an 
area of about four feet by two feet. They were made of maple 
wood alone, burned in close stoves, and were very heavy, and the 
