36 QUICKSILVEK DEPOSITS OF THE PACIFIC SLOPE. 



I think Hoffmann means to deny the opinion hehl by Dolomieu that quick- 

 silver and stibuite are volcanic emanations. Dolomieu, in his treatise on 

 volcanic products,^ does classify these minerals as products of sublimation, 

 but I have been unable to find any passage in his writings in which he men- 

 tions having observed them at Vesuvius. In his Voyage aux iles de Lipari 

 I find no allusion to the subject. It may be, ho wever, that in some of his 

 less known writings he gives the facts upon which his opinion was based. 



Noo-o-erath, writing in 1862, makes the comment that one may assent to 

 Hoffmann's view of the matter the more readily because, thus far, quicksil- 

 ver has nowhere been found in volcanic rocks, but since 1862 cinnabar and 

 quicksilver have been often found in volcanic rocks, and cinnabar and stib- 

 nite have frequently been discovered together. Prof E. de Chancourtois, 

 in his lectures at the Ecole des Mines, has been in the habit of showing 

 specimens of cinnabar and realgar which he found at Pozzuoli, near Naples, 

 at the opening of the principal fumarole, and which had been deposited 

 from the jet of aqueous and sulphurous gases.- Cinnabar as a product of 

 volcanic action thus exists near Mt. Vesuvius, if not upon it. 



Ndggerath records six localities in Sicily in which traces of cinnabar 

 have been found, but without any details as to occurrence or association. 

 One of the localities, Paterno, ten miles northwest of Catania^ is at the base 

 of Mt. ^tna. It would be very interesting to know what relation this oc- 

 currence bears to the lavas and hot springs which must exist not far from 

 it. I have been unable to learn anything further about it. 



Germany. — The qulcksilver deposits of Rhenish Bavaria have lost all 

 the commercial importance they once possessed, but not their geological 

 interest. They have been very fully described by Prof H. von Dechen' 

 and a digest appears in von Cotta's Ore Deposits. It is therefore un- 

 necessary to dwell upon them here. The deposits formed veins in rocks 

 of Carboniferous age, and to some extent impregnations in sandstones. 

 They were accompanied by a melaphyre (probably diabase), and ore was 

 sometimes found in spots and cracks in this rock, but a connection between 



' Jomual lU' iili.\>iiiiu, lU' cliiiiiie, d'histoiie iiatiirelle ct ilcs arts, Jean Claude Lametherie, vol. 1, 

 1794, p. 10^. 



JRollaud: Hull. Soc. uiiiidialosiciue, vol. I,ld7t<, p. 99. 

 ' ArcUiv fill- Mineral., Kaisteu, vol. 22, 1848. 



