THE 
AMERICAN GEOLOGIST 
Vol. XXIII. FEBRUARY, 1899. No. 2 
SIDE-LIGHT UPON COAL FORMATION. 
Ry W. S. Gresley, F. Ct. S., F. G. S. A. (Mining Engineer.) 
(Plate II.) 
I . The subject of the origin and formation of coal will always 
he one of much interest so long as there is anything ^/rzc to be 
said or Ay? to be foiuid out concerning it. While all investiga- 
tors seem to be agreed that coal (all varieties of coal) is of vege- 
table origin, they are by no means of one mind as to at least 
two very important points, namely: (i) tJic true character of 
tJic different kinds of plants involved^ and (2) tlie n tanner or 
7c>a_vs in ivliicJi these vegetable constituents, including residual 
products, were accumulated or deposited. 
As to the differences in physical structure and the lamina- 
tion and texture of coals, probably all agree that these owe 
their peculiarities to original differences in kind of plants and 
to circumstances of deposition. Moreover, no one disputes 
that certain coal-seams were formed differently from other; 
but I hold that there are serious objections to a belief in the 
''growth in place" theory, as generally understood, as appli- 
cable to normal coal-beds in this country as well as in Great 
Britain, e. g., the great "Pittsburg" seam ; the "No. 2" seam 
of Illinois; the "Top hard" or "Barnsley" bed, in England; the 
"lO-Yowd" of South Staffordshire, and others. 
So far as microscopy has been applied to throw light upon 
the origin of coal, French and German scientists seem to have 
in recent years gone ahead of English speaking investigators; 
and while their claims to the more startling discoveries of new 
facts which relate largely to micro-organisms, both animal and 
