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boniferous system of Scotland as one in which “ igneous rocks 
are rife ; ” the igneous rocks being this very trap which could lay 
itself so harmlessly at a white heat on clay-shale and ordinary 
coal, without even taking the colour or the smoke out of them ! 
The facts to which we call attention are just such as Kirwan, 
for example, published as early as 1799. He tells us that at 
Borrowstounness, in Scotland, a stratum of trap or whin is the 
immediate roof of a seam of coal, and at Hillhouse, near Lin- 
lithgow, a thin seam of coal is found beneath a stratum of 
columnar basalt. At Bathgate hills, strata of coal and basalt 
alternate with each other. His authority is John Williams, 
of whom Sir Charles Lyell says that he gave “ the best account 
of the coal strata.” Kirwan gives an instance from Hessia, 
in which a bed of coal six to ninety feet thick lies under a 
“ mass of trap or basalt 600 feet high.” He says that when 
the coal is some fathoms thick, it forms a stratum that, next to 
the basalt, is the best and most bituminous.”* Jamieson, in 
1800, published the results of his personal observation of the 
geology of the Islands of Scotland. Speaking of the island 
of Canna, he says that there the people who had worked 
the coal told him that it was from six to eight inches thick, 
and inclosed in whin rock. At Portree, in Skye, he “ observed 
a stratum of coal one to two feet wide, resting on basalt, and 
covered by a similar mass sixteen to twenty feet high.” At 
another part he saw coal only a few inches thick, ce covered by 
a stratum of basalt thirty feet high.” In keeping with these 
observations, Kirwan quotes Bruckenman, who “ found mussel- 
shells, ammonites, and corallites in the basalt of pretended 
extinct volcanoes of France,” and says te Doctor Richardson 
lately discovered, and showed me shells in the basalt of Bally- 
castle.”! Such testimonies might be multiplied to a very great 
extent ; and the wonder is how the facts testified escape the 
notice and fail to be quoted, at least for refutation or explana- 
See Kirwan’s Geological Essays, edition 1799, pp. 247 to 252, and 310 
to 311. The passage in Williams is worthy of quotation ; he says, u Strata 
of basaltine rocks are very common in many coal-fields in Scotland. There 
are several thick beds of this stone betwixt the different seams of coal at 
Borrowstounness, and one of them is the immediate roof of a seam of coal in 
that ground ; and there is a thin seam of coal below a beautiful bed of co- 
lumnar basaltes at Hillhouse lime-quarry, a mile south of Linlithgow. In the 
Bathgate Hills, south ot Linlithgow, there are several strata of coal and several 
strata of basaltes blended together, stratum super stratum. These instances 
may suffice as a proof that strata of basaltes are sometimes the immediate 
roof and pavement of strata of coal.” ( The Natural History of the Mineral 
Kingdom. By John Williams, F. R. S. A. Posthumous edition, 1810.) 
t Mineralogy of the Scottish Isles, &c. By Robert Jamieson, F. R. A. S., &c. 
Vol. ii. pp. 38, 57, 87, 88 (edition 1800). 
