Anthracite Coal of Rhede-Island. 91 
Chemical Characters. These have been already sufficient- 
ly indicated in the gh apis remarks. It remains to be ob- 
served that this anthracite decrepitates a thrown into an 
—— immer Wak not so powerfully as the anthracites of 
Foreign Butte. I have seen in the Rhode-Island coal, 
only small portions of pyrites. Between the seams of this 
coal, there are found thin veins or films of greenish talc, gen- 
erally not thicker than the blade of a pen-knife ;—chlorite 
and quartz are found in the same situation, and these foreign 
hodies, in addition to the earths which appear to be com- 
ined or mixed in the coal, and to the iron, contribute to form 
the slag. Asbestos is found i in the slaty rocks, accompany- 
ing the coal. T slates are not bituminous, but they are 
often impressed by ferns, (and other 2 gata bots these copies 
are in many instances singularly bol 
Characters of the anthracites of Pennsyloania.- 
Having, in the last volume of this Journal, written rather 
fully as to the general characters and economical uses of this 
coal, it remains to state its characters as a subject of scienti- 
mineralogy. The slight differences in this anthracite, 
from the various jocaiities, are scarcely appreciable, and in a 
scientific view a te be unim 
The colour is black, and in this particular, there is very lit- 
tle variety: in some specimens, it perhaps inclines a little to- 
= gray, but the difference is scarcely perceptible. 
e of colour. Like the Rhode-Island coal, it ap- 
able 4 very little change of colour, nor do we observe 
ee a any of those marks of iron rust that are so com- 
mon in the other, _and which give to many of the a aad 
a coarse and far 
a it mon pont wou spose tong 9 a comb 
Play of colours. ‘There is not in this anthracite any thing 
like the chatoyement of Labrador feldspar, adularia, fire or 
the 
derived probably from the decomposition of pyrites. 
Whatever may be the nature or the origin: Pee the colouring 
matter, few minerals equal the Pennsylvania anthracites, in 
