The Anaconda standard. [volume] (Anaconda, Mont.) 1889-1970, 1899-10-12

could be determined only by a long
chemical test"
| There are pyrites in the clay and
| the porphyry both, are there not?'
Yes. But while the pyrites are a
| constituent element in the clay, that is
| not so as to the porphyry They only
occur in the cracks in the porphyry, OF
where slight replacement has taken
| place in the structure"
The witness related the hard clay
to soft by saying that in the fault
| crevices where they occur there is a
graduated transition in the formation
from one to the other through interme-
diate FORMS within longitudinal dis
lance of five feet
Mr. Hughes asked the witness Wheth,
er or not the decomposition of quartz
porphyry results in a product in which
the percentage of alumina Is higher
than in the quartz porphyry, and Mr.
King said that that is the case where
the decomposition is sericitic, which Is
the case with the rock in the mine. MT.
Hughes then read five formulate of the
constituents of quartz porphyry, and
the witness agreed with them; also
other statements relative to the same
subject, which Mr.. King also agreed
with. The object of Mr.. Hughes ex-
tensive quotation of geological books
was to show a relation between the
quartz porphyry and the indurated
clay; or relation between their decom-
posed products, or constituent elements,
or chemical changes.
A long discussion Of vein quartz crys-
tails took place, and a great many sup
postional cases involving the operation
of various chemical agents were put
to the witness.
Mr.. King was asked by Mr.. Hughes
if quartz porphyry could not be de-
composed by water in a certain way
and produce a substance containing
certain chemical constituents, and he
said that it could, but he added that
the chemicals would not prove that the
material had been evolved from quartz
porphyry. Asked if this decomposed
product would not be like the material
in the clay slides he had examined, he
said it would not, and explained the
difference Then Mr.. Hughes went into
the particular conditions present in the
clay slides and not present in the de-
composed porphyry and the witness
described them in detail. One condi-
ton was that the crystals in the slides
are closer together than in the por-
phyry. Mr.. Hughes asked Mr.. King if
the crystals would not necessarily be
closer together after certain changes in
the material had taken place, and he
answered in the negative, though ad-
hitting that they might possibly be
closer together.
rs it not a fact that the closeness
of the crystals does not prove that the
material is not decomposed porphyry?"
asked Mr.. Hughes.
THE closeness of the crystals alone
does not prove that, but taken with
the other conditions, it is a proof" an
sWered the witness.
A discussion of the chemical tests
made by Mr. Sands of the indurated
clay and the quartz porphyry in the
mine occurred and a question as to
the quantity Of air carried in the air
cells Of silica arose.
Il have seen silica floating down
river" said Mr.. King.
ION a raft or a steamboat" asked
Mr.. Hughes.
''On neither, sir: in the water. I was
told that I should see rock that would
float and wood that would sink in the
country where that occurred. 1t was
on the banks of the Truckee river.
There was a bank of silica there, and
you could tear piece off as large as
your table and throw it in the river and
it would float. And the mountain ma
hogany timber woIld sink"
Mr.. King said that he never saw
quartz porphyry ina mine fulfilling the
chemical conditions set up by Mr..