374 Chemical Examination 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, with a 

 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, a 

 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. 



