e is found will reveal some points of
difference from the enclosing rocks at other parts of the course of the
lode, and when ore shutes are found parallel in reefs running on the
same course, bands or belts of similar country rock will be found at the
productive points. From this we may fairly reason that at these points
the slow stream filling the lode cavity met with a reagent percolating
from this particular band of rock, which caused the deposition of
its metals; and, indeed, I am strongly disposed to believe that the
deposition of metals, particularly in some loose lodes, may even now be
proceeding. But as in Nature's laboratory the processes, if certain, are
slow, this theory may be difficult to prove.

Why the junction of lodes is often found to be more richly metalliferous
than neighbouring parts is probably because there the depositing
reagents met. This theory is well put by Mr. S. Herbert Cox, late of
Sydney, in his useful book, "Mines and Minerals." He says:--"It is a
well-known fact in all mining districts that the junctions of lodes are
generally the richest points, always supposing that this junction takes
place in 'kindly country,' and the explanation of this we think is
simple on the aqueous theory of filling of lodes. The water which is
traversing two different channels of necessity passes through different
belts of country, and will thus have different minerals in solution. As
a case in point, let us suppose that the water in one lode contained in
solution carbonates of lime, and the alkalies and silica derived form
a decomposition of felspars; and that the other, charged with
hydro-sulphuric acid, brought with it sulphide of gold dissolved in
sulphide of lime. The result of these two waters meeting would be that
carbonate of lime would be formed, hydro-sulphuric acid would be set
free, and sulphide of gold would be deposited, as well as silica, which
was formerly held in solution by the carbonic acid."

Most practical men who have given the subject attention will, I think,
be disposed to coincide with this view, though there are some who hold
that the occurrence of these parallel ore shutes and rich deposits at
the junctions of lodes is due to extraneous electrical agency. Of this,
however I have failed to find any satisfactory evidence.

There is, however, proof that lodes are actually re-forming and the
action observed is very interesting as showing how the stratification
in some lodes has come a