DAMP. 
quently aa to a experiments, with a view 
to afcert Sir James 
w 
ae . common fuanel o 
t ae holes or crevices in the coal, 
ues, fometimes with con- 
fiderable force,) and tying a omnia bladder on the pipe 
of the as after the gas - . oes from it for aie time, 
My experiments were ma e gas, abont feven day 
after its oe fir it aed At ha time sy badder were 
perfeally dry, an and fhewed no figns of putre 
e general see - thefe experts (a8 wer in a 
ir which w in Januar , before the Medi- 
cal Society of Esinbr ay ) re the fallow The gas was 
of nitric Bro n Mr. Dalton’ s mee 
It had 
Whe en “tet ton fire, as it ried from ae 
,it burned with a dark blue flame; and 
veflel, held over the flame, was foon 
Mixed with common air, it did 
a he approach of a lighted taper, at leaft in 
any eraponio n that was tried. The utmolt effe was a 
deep blue flame, which {pread quickly through the veffel, 
but was not 
gas, however, it exploded, and gave a loud report. On 
agitation with lime water, it loft about ~,th of its bulk. 
The ft tefts did not difcover any admixture of ful- 
phurated hydrogen. One hundred parts by meafure ap- 
peared, therefore, to confit of 
63.34 atmofpherical air 
1.66 carbonic acid 
35.00 inflammable gas 
100.00 
«The nature of the inflammable gas was next afcertained 
Reducing the refults to a 
3 
ai iillintg pit-coal, the fire-damp appears to “differ a “little 
from both thefe gaffes. 
** It was defirable, however, to repeat the analyfis of fire- 
n air; and for this pur- 
lowing refu 
“From ce action of nitrous gas and lime-water, the gas 
appeared by Dr. Thomfon’s experiments, to contain in 100 
meafures, 
63.0 inflammable gas 
6.5 oxygen » 
25. 
5c carbonic acid 
100.0.” 
Notwithdanding: 4 all the above-mentioned fa&s, experi« 
ments, and obfervations, the real origin cf the gaffes which 
heat eafily extricates that gas from the above-mentioned mi-« 
that whenever any fermentation, or any heat 
arifing from various caufes, happens to at upon fuch mi- 
nerals, the extrication. of carbonic acid is a natural confe- 
quence. But the origin of the hydrogen gas is not equally 
clear. It was formerly a prevailing opinion, that the in- 
pees ews gas was furnifhed by the decompoiition of water 
on ftrata of pyrites, efpecially thofe oO 
coniteriig that the folution 
y the action of pyrites upon 
who exprefsly mention their not a ig found any far 
ted hydrogen in the fire-damp w they exa 
we confider the various (esa ree el different 
materials which almott every excavation, and efpecially coal 
t which is at prefent 
cultivated unde € 
whic 
a hus ftated every thing which feemed to be of 
importance with refpe& to the damps, which have infelted 
from time immemorial, and do adtually continue to infeit 
mines of almoft every kind; we fhall clofe this article with a 
fhort account of two other, much lefs authentic, or much 
lefs known, kinds of damp. The account (which is con- 
tained in the Philofophical Tranfaétions, as given by the 
fame Mr. Jeflop, whom we mentioned above) is as fol- 
OwWs ° 
“ They call the third fort the pea/e-b/oom ne becaufe, 
as they fay, it fmells like peafe-bloom. They tell me it 
the fummer-time 3 and hoe 
which the lime- ane meadows in the Peak do much abou: 
The fourch damp is the ftrangeft and mott pettiential of 
any, if all be true which is faid concerning it. hofe who 
pretend to have feen it (for it is vifible) defcribe it thus. In 
the higheft part of the roof of thofe paffages which branch 
out 
