32 M. Mobs' Summary of Geognostical Phenomena. 



observations, in so far as individual small veins (Trihnmer) of 

 this kind are met with, find also their application here. 



Passage of StocJcwerfa info beds and veins proper. — Sometimes 

 the small veins (Trilmmchen) of Stockwerks, slender at first, 

 increase in width, and so approach one another, that not only 

 do the repositories thus become richer, but likewise entirely 

 change their nature and constitution by several uniting, and at 

 last forming a single individual. On the one hand, there thus 

 arise regular beds, at first still provided with their lateral and 

 companion veins, but ultimately as tabular masses contained 

 between roof and floor ; and, on the other, regular veins, at 

 first also with their accompanying offsets, but afterwards as 

 masses contained between their salbandes (Saalbandern) ; and the 

 first intersect the structure, just as often as the others lie partly 

 conformable or parallel to it. There are individual examples, 

 as well of beds as of veins, in which we meet simultaneously 

 with all the differences hitherto spoken of, and which, in one 

 part, consist of mere single small veins (Trilmmern), but 

 in another, form a more connected mass, only here and there 

 accompanied by such little veins, and which, finally, not unfre- 

 quently appear as repositories which are completely bounded, 

 not unfrequently, by distinct concretion-surfaces and separat- 

 ing layers (Bestege) ; and we may quote as such, some of the 

 copper-ore repositories in the Tyrol for the bed-like forms, and 

 some of the lead-glance repositories of the Hartz for the vein- 

 like forms. But repositories of both kinds, which are for their 

 whole extent of uniform characters, are the most usual, and of 

 these, those which appear as connected masses are the most 

 important. These are the beds and veins in their proper and 

 usual mining and geognostical sense. 



Beds, and the materials of which they are composed. — The 

 general properties of beds already mentioned in the pre- 

 ceding pages having been premised, I wish more particularly 

 now to notice that all these repositories do not consist en- 

 tirely of ores, but that what is contained between the roof 

 and floor as the actual mass of the repository, often appears 

 as a combination of ores and other minerals. Sometimes 

 the mountain-rock itself forms the mineral substance of the 

 bed, as is very often the case with limestone and slaty rocks ; 



