94 Anthracite Goal of Rhode-Island. 
kill coal are however much more magnetic, and the slags 
‘which form in the furnace, are respectively much more mag~ 
netic than the ashes. The ashes of the Schuylkill coal are 
of a reddish colour, not unlike those obtained from the 
Rhode-Island coal, and it is not improbable that the colour is 
‘owing to the same cause ;—although I am not aware that any 
analysis of this coal has been executed. 
Foreign Bodies. The structure of this coal is so close 
that there is not room for any foreign body to be interpo 
in seams, which in fact do not exist, except between the great 
masses of coal and the contiguous layers of strata. ‘There 
is rarely on these surfaces a plumbaginous aspect, and when 
it exists, it is less remarkable than in the Rhode-Island coal. 
The only foreign bodies that I have observed in this anthra- 
cite, are some portions of pyrites, generally small—some of 
them cupreous—more frequently distinct spots and layers of 
carbon, exhibiting the precise appearance of vegetable char- 
coal. Its structure is, generally, in fine fibres; it is nearly 
without lustre, and presents a striking contrast to the brilliancy 
ef the surrounding anthracite. 
The slates, which are contiguous to this coal, abound with 
distinct and beautiful vegetable impressions, as described by 
Mr. Cist, in his memoir, in Vol. IV. of this Journal, to which 
I refer for the geological relations of this coal. 
Miscellaneous Remarks. 
Where the conducting tube, that connects the furnace with 
the chimney, is vertical, it appears to be strictly true, as stated 
in the former memoir, that it needs little or no cleaning. 
But I find that where there is a considerable length of hori- 
zontal tube, the ashes, transported by the strong current, ac- 
cumulate in considerable quantity, and although they are 
entirely incombustible, and therefore completely different 
from the soot of a comn i , it is requisite to remove 
them occasionally. Once, or at most, twice, in the course of 
the season, will be sufficient. The tube must be taken down, 
carried out of doors, and the ashes poured or jarred out, 
simply by raising the tube on end. As they are entirely 
ry, they run out as sand would do. Their colour, modified 
by the black dust of the coal, is darker than that of the ashes, 
which fall through the grate. 
