88 Anthracite Coal of Rhode-Island. 
sionally among the slates which accompany this anthra- 
ci 
Ci Lange of colour does not appear to be a common inci- 
dent of the Rhode-Island coal. Its colour is remarkably 
rmanent. Atmospheric influence, including the various 
agencies of temperature, electricity, &c. aided by chemical 
action, often extends many feet and even fathoms into the 
solid materials of rocks themselves; so this coal is often al- 
tered in the same manner, and the seams are then lined with 
red oxid of iron, giving fresh pieces a mottled ‘appearance. 
Such masses are, however, always rifty, while those that are 
solid, are, in a great measure, free from these appearances. 
Play of colours is, I believe, never observed upon the 
feeds island anthracite, at least to any degree that is re- 
markable. The beautiful hues of the iris, so common in the 
Pennsylvania anthracites, are in vain sought for in that of 
Rhode-Island, at least in any econ that I have 
Occasionally there are thin veins of pyrites, which, by their 
n, produce both ices and play of colours'in:a 
Reatee, and to a moderate extent. 
The lustre of this coal is semi-metallic. In fresh and un- 
injured specimens it is shining, and even sometimes splen- 
2 in such cases the lustre is composed of the metallic, 
the vitreous and the resinous, united. 
* Professor Vanuxem’s analysis of of Rhode-Island, and of 
sien erie a Pests 
which contain the same cquatitneae parts, varying only in proportien. Car- 
ingredient ; the iron, ' 
5 
p 
the seeoed to ee in the same consoe, substantially, in which it exists in 
mond).sed wi were it freed entirely from foreign substances, and crys 
: — am a. aware, that plumbago has ve thooe Poca in furnaces, for the 
ee oo. for domestic e ae or for the purposes of the 
og arg € now see done, ev oxy day, with anthracite, it is pre 
ie that p umbago might, were there any inducement, be consumed in f 
na ache ae with intense ig anthracite. Its i ity, 
periments. ong been now questo 
the coolpatibitiey of the di aga mew hy tnd oh the " ne 
— it is ‘probable that e very dense aggregation of this substance 
rning in furnaces, 
ficient party aa to prevent such small bodie s from choking aa sean) 
whole world now kn that it b 
e focus of the ee etieees bh ai aie urns in the ws focus, and rapidly iP 
