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

pie which Mr.. King had made became
the subject of consideration. Paraf-
| fine had been used in the test, and Mr.
| King said that it had been used fol-
| the purpose of increasing the accuracy
| of the test.
Il was about to ask If it would moi
| rather decrease the accuracy" said
| Mr.. Hughes.
Mr. King did not agree to this, and
| lengthy discussion of the effect of the
paraffine followed.
The decomposition of porphyry was
| discussed.
What is the first effect upon the
rock of whatever agency 1t IS that
decomposes it?" asked Mr.. Hughes.
The feldspar is first attacked said
Mr.. King.
The result is to lessen the quantity
of feldspar, them"
Yes"
How would the lessening of the field
spar affect the silica?'
1T would affect it by chemical IN
1uence so that it might go or stay, L
could not say
Would it not increase the relative
per cent. of silica, even if the silica
remained just as it was?''
1t would
Mr.. Hughes put q theoretical case OF
chemical changes. and asked Mr.. King
II the theory lIlNolNtu W dS Soi GU. -Al.
King answered that the theory was
correct if the chemical changes We're
possible, but that they were not pos
sible.
The witness explained that the field
spars in the quartz porphyry are al
ready decomposed feldspars.
The comparative characters of kao-
lin and sericite which is an altered or
decOmpOSed form of feldSpaf. were dis
cussed, and Mr.. King said that under
optical tests little difference is to be
observed in the appearance of the two
substances.
The witness said that he did not
think the stages of decomposition that
feldspar passes through in being trans
formed into kaolin are known.
Mr.. Hughes read formula for kao-
lin from a book on mineralogy. He
asked Mr.. King if he regarded the for
mula as fairly or approximately cor
rect, and Mr. King said that he did,
but that the elasticity of mneralos-
ical formulate is very great The for
mula read gave certain percentages OF
silica, alumina and water as the con-
stituents of kaolin. The witness said
that the water was microscopic mois-
ture, and that it forms one of the diff
ferences that exist between kaolin and
sericite The water or MICROSCOPIC
moisture in kaolin is an accidental, I'M
involved element, While in Ser1clte the
water is concerned in the phenomena
of decomposition.
Mr.. Hughes read a long description
of quartz porphyry from a geological
work in which it's constituent elements
and varieties were given and compari-
son was made between it and other
rocks.
What do you say to that definition
of quartz porphyry?' asked Mr..
Hughes.
II think it is a very fair summary,
but I don't know how much modiflca~
ton that classification, as it relates to
special varieties, is subject to- 1t is
being continually found that rocks &C
copied as eruptive are metamorphlc,
and rocks accepted as metamorphlc are
eruptive," said Mr.. King.
Mr. Hughes read another definition
of the composition of quartz porphyry
from another book, by Williams.
What do you say to this classical
tion?" asked Mr.. Hughes.
Il think that Mr.. Williams is not a
Photographer in any sense. He is, per-
haps, microscopic and a compiler.
At any rate, he is not a first-class
authority" said Mr.. King.
He explained a mistake, or what was
inferred to be a mistake from his treat
ment of it, that Mr.. Williams made as