346 THE JOURNAL OF GEOLOGY. 
think these objections valid. The stratified form, he argues, might 
readily be due to the impermeability of the Sohlenstein, which would 
cause the waters to flow along the contact between it and the perme- 
able dolomite above, while the carbonaceous Vitriolletten bed would 
precipitate the ores. The unoxidized condition of the dolomites and 
clays does not mean necessarily that no waters traversed them, but 
merely that these waters had no air or free acids in solution. Such 
could well have been exhausted, says H6fer, in oxidizing the sulphides 
of the higher strata, before transporting them to the present ore hori- 
zons. Further, Héfer reasons, on the hypothesis of sedimentation, 
beds of dolomite and limestone would have been deposited in alternate 
layers in the ore body, as they were before and after. Not only is this 
not the case, but Bernhardi describes a brecciated structure which 
sometimes characterizes the greater part of the deposit, where blocks 
of dolomite are cemented by the ore. This condition, as well as the 
presence of vertical and other ore-bearing crevices in the dolomite, 
is incompatible with a sedimentary origin of the ores. Hence, Héfer 
thinks, this hypothesis must be abandoned. 
Althans, in discussing the source of the ores, shows that Krug von 
Nidda’s explanation, that the solutions came from below through pipes 
or chimneys, will not hold, because when such pipes have been followed 
into the Sohlenstein they have always come to an end. 
Against Dr. Kostmann’s hypothesis, that the solutions came from 
the interior through crevices or fissures, are the facts that the fissures of 
the Coal Measures almost never extend into the Triassic; that there 
are no deposits in the underlying bituminous Sohlenstein, and that no 
such source of supply has been encountered or is indicated in mining 
operations. H6fer, therefore, discards also the hypothesis of ascend- 
ing solutions. 
The remaining alternatives are defined as follows : 
1. The metals were originally diffused in the sedimentary complex 
overlying the Sohlenstein and subsequently leached out and deposited 
at the present ore horizon. 
2. The ore deposits were originally concentrated sediments which 
acquired their present forms by subsequent rearrangements and 
changes. 
The first of these hypotheses was advanced long ago by Carnall, 
and was accepted by Websky, Runge, R6mer and others. These older 
authors referred to the dolomite alone as the source of the ore, and 
