February, 1S44.] 9 



From seven samples of coal from different mining districts wero taken, at 

 random, specimens for analysis. 



per ct. 



From the lirst sample, specimen i a had a sp.gr. 1.438, and gave of ashes, 18.99 



specimen { b « 1.424 « » 18.318 



» second do. " ia « 1.322 » « 5.653 



\b « 1.305 « « 5.239 



third do. « la » 1.304 « » 4.081 



£ o « 1.309 « «« 6.519 



« fourth do. « U « 1.339 « •« 9.109 



« |i « 1.325 " " 7.398 



fifth do. « la » 1.315 « « 10-090 



£6 « 1.335 « « 11.071 



« sixth do. « U « 1.347 « « 13.768 



^b " 1-329 « « 11.071 



« seventh do » Co, " 1.511 « » 21.250 



lb « 1.289 " » 6.080 



2. He also called attention to the fact that, from the same hand specimen, 

 may often be obtained widely different results by analysis. A small specimen 

 was shown, in which were displayed most decided differences of structure, lustre, 

 colour, character of powder, amount of volatile matter, amount and character of 

 impurities. This was a specimen of coal from the Cumberland coal field of Mary- 

 land — in which a portion was columnar and crystalline in form — of a deep jet 

 black colour, shining and friable, giving abrown powder, and when coked, yielding 

 a highly intumescent porous mass, and leaving, when completely incinerated, only 

 1.754 per cent, of reddish yellow or fawn coloured ashes, exceedingly light, and 

 liable to be carried away by the slightest motion of air. The same part yielded 

 18.28 per cent, of volatile matter, and consequently left 79.966 per cent, of 

 fixed carbon. The other part of the specimen was amorphous in structure, 

 tough in consistence, dull, and almost destitute of lustre, yielding, when com- 

 pletely pulverized, an almost black powder. It gives, when incinerated, 14.736 

 per cent, of ashes, of a greenish white colour, very dense, and cohering slightly 

 when strongly heated. Its volatile matter is 15.976 per cent., and consequently 

 the fixed carbon 69.288. The coke produced swells more or less, according to 

 the rapidity of the application of heat. 



3. He adverted to the designations red and white ash coals, and exhibited 

 proofs that mere analysis, on a minute scale, is liable to mislead us in regard 

 to the true character of the earthy residua of the coals in question. He exhibited 

 a sample of ashes and of clinker, from Lackawanna anthracite, obtained from 

 the combustion of two tons of that coal ; and also a specimen of ashes from the 

 analysis of a hand specimen, — the former being dark brownish red, and the latter 

 almost perfectly white. 



4. He presented evidences of the effect of the rate of heating on the amount 

 and character of the coke produced from a given weight of coal of the same 

 kind, showing that when a brisk and intense action of heat is made the means 



2 



