Quartz and Metalliferous Veins. 349 
Just as in the deposits of those springs at the earth’s sur- 
face, to which we formerly alluded, an alternation appeared, 
known, that some of their veins display a regular ribbon-like structure, 
in as much as their minerals form parallel layers variously alternating with 
each other. (Zonen, Streifen, Bander oder Glieder.) However, according 
to my notions, there has been more regularity discovered in this, than 
is consistent with direct observation. There has also been fixed for 
many formations a distinct epochal series of their members. It has been 
assumed, for example, that quartz forms the outer member next the walls 
of the vein ; the spars, on the other hand, the inner or middle members . 
Even Werner’s theory of veins (amongst others § 31) contains very dis- 
tinct remarks on this. But more recently persons have gone further, 
and have raised up a theory of the development of veins upon it. It 
has been further assumed, that, as the depth increases, either the inner 
newer members disappeared, and the outer became more predominant, 
or, vice versa ; from which the enrichment and impoverishing of a vein 
according to the depth have been explained. This may be the case in 
certain veins ; but it does not appear to me to be founded on a per- 
vading or completely established law,” &c. 
“Even a regular memberment of the vein stuffs is not a predominat- 
ing circumstance. In many cases there exists no trace of it. Still sel- 
domer, however, is there a constant epochal series in the individual 
members. For one example, in which the one or the other may be 
proved, there are many others in which this is not the case ; where, rather, 
the different kinds of ore and matrices lie intermixed irregularly, as if 
poured together in one cast; or where the epochal series of the indivi- 
dual members does not remain the same. Isolated regularly membered 
veins have ever attracted more especial attention, because they are more 
interesting than others. Hence the great number of opposing appear- 
ances seem to have been less observed. I have therefore directed espe- 
cial attention to this point for some considerable time ; and when I have 
adduced more particularly the results of my observations for each parti- 
cular formation, in a future complete exposition of the foregoing sketch, 
it will be seen that the general legitimate deductions which can be made 
from these, are only few. There are only a few minerals which prove 
themselves to be the newest formations, alike in druses and as the in- 
nermost members of the vein—for example, native silver, sulphuret of 
silver, (silver glance,) ruby silver, calespar; others occur again and 
again alternately, next the walls and in the middle—for example, quartz, 
pyrites, brownspar, barytes,” &c. 
It is indeed difficult to decide between two men such as Freiesleben 
and vy. Weissenbach, both practised in observation, and both, by their 
long calling as practical miners, in a position to study the most various 
relations of veins. Although the latter is inclined to assume a determi- 
nate epochal series of the members of veins, he by no means ignores the 
