78 Dr Boue’s Observations on M. Beudanfs Opinions 
Plutonic way ; so that he would almost assuredly have been 
obliged to adopt the same idea with regard to the old pitch- 
stones, had he admitted that they existed in veins. 
At Planitz, in some localities in Scotland, in the Thuringer- 
wald, pitchstones form imbedded or wedge-shaped masses. In 
the Trebitschthal they present themselves in the form of a great 
imbedded mass, or a kind of short bed ; and, in the Palatinate, 
they have the form of a more decided short bed. The masses 
or short beds at Mohom are situate in tuffaceous beds, limited 
to a small space, of which the base is more or less argillaceous, 
and contains rolled masses of gneiss, &c. ; and the pitchstones 
show also these fragments of gneiss, which have been accident- 
ally inclosed in this rock at the time of its elevation, an appear- 
ance similar to that presented by a pitchstone-vein in Arran. In 
the Valley of Trebitschthal the pitchstone-mass rests upon por- 
phyries, with which it is of contemporaneous origin ; their supe- 
rior position and their nature has enabled them to cool more 
rapidly. In the same valley small pieces of pitchstone are im- 
bedded in the tuffaceous sides of the porphyry-vein at Tanne- 
berg At Planitz the vitreous mass seems to traverse the red 
sandstone, and not to have been far from the central volcanic 
action. In the, Thuringerwald, and in the other points of the 
Erzgebirge, the masses of lithoid pitchstone are associated with 
porphyries, and pass into them ; they seem only to be parts 
sooner cooled than the rest. In the Palatinate, the black pitch- 
stone of St Wendel forms a kind of short bed or mass upon 
sandstones ; it is associated with porphyries, and presents igneous 
appearances ; one can scarcely decide whether it be a vein or a 
kind of stream. To this point alone could be referred M. Beu- 
dant’s account of the alternations of pitchstones, sandstones, 
coal sandstones, and slate-clays. It is evident that he ought to 
have mentioned the accessory circumstances, and not speak of 
these alternations as if the pitchstone were a rock alternating 
with sandstones, as the slate-clays do, and with the same fre- 
quency as these latter rocks. 
Having in this manner attempted to appreciate the alleged 
alternations of pitchstone and arenaceous rocks, we see nothing 
* See iny Memoir on Germany, 
