292 
I now pass to the American coals. The samples which if 
have examined were not selected for making microscopic 
sections; they were collected by myself, eight years ago, 
simply as specimens of American coal. I am, therefore, 
unable to give the stratagraphical section of the seams from 
which they were taken. In one way there is an advantage, as 
it is a guarantee of their being ordinary samples, and in no 
way selected for the purpose to which they have been turned. 
The first coal to which I shall draw attention was taken 
from the Black Warrior Coalfield of Alabama. And I may 
here state, by way of parenthesis, that the mineral wealth of 
that State is but little appreciated. The future of Alabama 
cannot be otherwise than of great importance. The coal 
presented a brigh lustrous appearance throughout, though 
some layers were more lustrous than others. Macrospores and 
Microspores were present, (Figs. 34, 35, 36, 37) but they did not 
constitute the whole mass. Vegetable tissue was detected, and 
a large quantity of hydrocarbon. The Microspores exhibited 
the triradiate markings before referred to in English coals, and 
they appeared to be identical with those found in the lower bed 
of the Welsh “Four Feet,” (Figs. 4 and 38.) The Macrospores 
were not numerous, the most perfect one found is shown 
in Fig. 34. . 
The next coal examined was collected near Pittsburg, 
Pennsylvania. The lustre was bright, and the chief structural 
constituent discovered was hydrocarbon. Vegetable tissue was 
also present, some having the appearance presented by decom- 
posed scalariform tissue. Spores were numerous in some 
layers; these were chiefly microspores, (Fig. 33) resembling 
those of the “ Better Bed,’ and measuring about :0015 of 
an inch in diameter. Macrospores were present, but mostly in 
a fragmentary state, (Fig. 31.) 
Comparing the structure of English and American Coals, 
the material which I have referred to as hydrocarbon is present 
in both; the same class of vegetable tissue was detected, and the 
spores were allied. It is, therefore, clear that some seams of 
coal in both countries had a common origin—vegetable origin. 
