374 Chemical E'xamination of Bituminous Coal. 
steam, while its coke maintains a solid ignited mass, ready at all 
times for the renovation of the activity of the blaze on the addi- 
tion of more coal or of wood. 
In a grate it burns very well when mixed with the anthracite, 
and the fire is active, cheering and enduring. 
The Mid Lothian coal, being remarkably free from pyrites, 
there appears to be no serious danger of its producing spontaneous 
combustion—an accident which, in the case of mineral coal, is 
generally attributed to the fermentation of pyrites; the sulphur 
and the iron both attracting oxygen from water, as well as from 
the air in the interstices of the coal, until it becomes ignited. It 
should not be forgotten, however, that many combustibles besides 
coal, are liable to spontaneous combustion, and therefore care is 
always to be observed in disposing of them in store-houses, on 
ship-board, &c., especially when accumulated in large quantities. 
From the absence of sulphur, we should think this coal well 
adapted to the manufacture of bar-iron, and that in employing it 
for locomotive engines and the boilers of steam-ships, or of fixed 
establishments on shore, there can be no cause to fear that it will 
injure the metal, whether of iron or copper. 
As to its use in sitting and sleeping rooms, there can be no in- 
jurious influence to health, provided there is a good draught up 
the chimney ; otherwise every species of fuel is dangerous, as 
the gases produced by combustion are all deadly; but, witha 
good drawing vent, there is no more danger from the Mid Lothian 
coal than from any other, and no danger indeed from any. 
It is worthy of remark that whenever a coal fire becomes lan- 
guid on account of the discharge and consumption of the gas, @ 
billet or two of wood instantly renews its activity and prepares 
it for the reception of more coal, which is then promptly kindled. 
Presuming, of course, that the coal furnished to us by the pres- 
ident of the Mid Lothian company, presents a fair average of the 
‘produce of the mines, we hesitate not to recommend it as an eX- 
cellent fuel, which has no occasion to shun a comparison with 
the best mineral coal of this country or of Europe. 
Yale College Laboratory, Feb. 7, 1842. 
