152 Professor Keilhau on Contact Products, 



of sublimations from furnaces in the interior of the earth, and 

 of fusions, in short of the action of " fire." On this subject, a 

 multitude of important facts are partly denied, partly misin- 

 terpreted, and the path is obstructed to points of view, from 

 which new and instructive considerations might be obtained. 

 I shall not be discouraged by the inattention hitherto paid to 

 my repeated attempts to direct attention to the many indubi- 

 table facts, which shew, that the generally received doctrine 

 of the pyrogenic origin of contact-products is hasty, and 

 must be retracted. I continue to beg that geologists may 

 test such facts, of which, therefore, I shall here also adduce 

 a group. In my memoir, entitled " Einiges gegen den Vul- 

 kanismus^^ (p. 75-6), I brought forward the following: — 



a. Near Commern, there rests, on greywacke, a transition 

 limestone, which, at the junction with the former, contains 

 large masses of ironstone, that are mined. 



b. In the Harz, also, beds of ironstone lie at the junction, 

 between limestone and greywacke. 



c. The ore at Rammelsberg, near Goslar, is situated be- 

 tween clay-slate and greywacke-slate. 



d. At Zellerfeld, in the Harz, the mine of Herzog- August 

 is excavated in a vein, which has limestone on the one side, 

 and clay-slate on the other. 



e. Near Iserlohn, the masses of calamine are placed be- 

 tween greywacke and limestone of the coal-formation. 



/. The mine Tschakirskoy, in the government Kolyvan 

 (Asiatic Russia), is situated in a repository of ore, at the 

 boundary between limestone and clay-slate. Near Nerts- 

 chinsk, a similar repository lies in the same manner, between 

 the same rocks, 



The following are additional examples : — - 



g. Near Brzezina, in Bohemia, a red ironstone occurs, 

 which a geologist of the dominant school of geology thinks he 

 cannot regard as of pyrogenic origin, but which is considered 

 by him as a deposit produced by mineral water. Between this 

 substance and the surrounding greywacke there are found — 

 compact cinnabar, heavy spar, iron-flint, and iron-pyrites, 

 which are extracted by mining operations. (Noggerath's 

 Ausflug nach Bohmen, p. 384.) 



