14$ Dr Bone's Geolog ical Comparative View of ike 
jasper of Hausmann, similar to the black shelly rocks of Port- 
rush and Skye. 
The Bohmerwaldgebirge is a great mass of gneiss, slate and 
granite. The granite forms in it large masses, or only conical emi- 
nences sometimes hidden by the gneiss, or occurs in veins of a 
more recent origin, and with many beautiful minerals, as tourma- 
line, dichroite, andalusite, tantalium, &c. The domes of granite 
are here and there abundantly supplied with kaolin, which is 
certainly intermixed with much scapolite, either disintegrated or 
nearly in its primitive state. Even the gneiss often contains 
kaolin, and many small veins of granite. Specular iron-ore and 
graphite are seen in it, and sometimes most abundantly, so as to 
seem to occupy the place of mica. According to my specula- 
tive views, we see here a long and great action of the 
subterraneous agents, and the existence of so much iron and 
graphite is a consequence of this : the first is a produce of 
sublimation, as in the extinct volcanoes, the latter an alteration 
of glance-coal or anthracite, in the same way as this substance has 
been changed by trap in Scotland. This leads to the idea that 
diamond may have been formed in the same manner, and might 
also be searched for in gneiss-like rocks, and in granite or sienite, 
while the grains of platina, like those of titanitic iron, sufficiently 
indicate their origin from the destruction of granitose unstrati- 
fied rocks. And here I may remark, that it is a singular cir-, 
cumstance, that the Bavarian travellers in Brasil found the 
rocks of that country perfectly similar to those we have just 
mentioned, for almost every specimen of that distant country has 
its analogous one in Bavaria. Some veins of porphyry exist also 
in the gneiss of the Bohmerwaldgebirge (Bodenwehr). 
The structure of the secondary formations of the Alps has 
puzzled many geologists ; yet, the means of cutting the Gordian 
knot have been given by Escher, De Buch, Mohs, Lupin, Ut- 
tinger, Pantz, Keferstein, &c. The writings of these excellent 
geologists, together with the judiciously managed travels of M. 
Buckland, have enabled us at last to acquire a distinct view of 
this part of the alpine regions. It would be quite useless for 
me to relate my own observations in this place, were I not of an 
opinion different from that of Professor Buckland upon the 
newer deposits of the Alps. 
2 
