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'PRACTICAL MINING AND THE
GENESIOLOGY OF GOLD.'
We have received a copy of a little brochure
by Mr. J. C. F. Johnson, M.P., entitled
'Practical Mining, and the Genesiology of
Gold.' It conBiBtB of a series of articles having
reference specially to gold and gold mining,
but often dealine with mining eeneraUV. Mr.
Johnson does not desire that ma book Bhould
be considered a scientific treatise, nor does
he regard it as a comprehensive guide to the
miner. He pots it forward apparently as the
expression of his views on certain departments
of mining for the benefit of ' non-scientific
practical' men, such aa he claims to be himself.
And it may be stated that when the author is
practical what he has to say is of v&lne, bat
when he goes aside from actual practice and
theorises, he lays himself open to grave crib
ciEm. The first article in the book relates to
the formation and management of mining
companies, as to which Mr. Johnson gives
tome excellent advice tbat would save the
waste of much time and money if it were acted
upon. The seomd article has reference to
alluvial prospeoifp?; and much in this is inte- ,
resting and instructive, A serious mucanoep
tion may, however, arise from one of the -
author's statements which should be put right.
He sayB:— 'The novice who fa trying to follow
or to find a deep lead mast folly understand
that the present bed of the surface river may
not, in fact seldom does, indicate the ancient
watercourse,' On the contrary it is pointed
oat by Leek that in Victoria almost all the
leads run parallel to the modern rivers, while in
California they are commonly at right angles
to the latter, and these facts are specially
noted as being a guide to prospectors.
Tbe author refers to the Mount Morgan ore as
having been formed by a hot spring ; following,
doubtless, tbe opinion of Professor Jack, ex
piessc d some time ago. It should, however, be
stated that competent authorities now regard
the ore as the result of a decomposed pyrites
foimation, for the veiy good reason that
pyrites, baa been found (here in a state of
partial disintegration. In a long article on
' Lode or reef prospecting' the author goes with
some detail into the general characteristics of
lodes, and gives much useful information to
prospectors in regard to testing aariferou
reefs. Hia remarks, however, u to machinery
for working gold reels, though fully warranted,
are too cursory to be of moon practical value.
Tbe same thing may be said of tbe next
article, which, though having the rather Wide
title 'The extraction of metalB— secondary
processes and lixiviation,' covers bat a few
paces and dealB only with a few methods of
gold extraction, and that -briefly. This,
completes the - 'practical mining' por
tion of the litUe work, the remainder
being devoted to a coupto- # wst^rpo
the 'generiology of gold,0 the. «r»t
leferriix? to lodes, and the second toallavUl
|old. It « here that Mr. Johnson in a ptmm
worthy attempt to set the problein of lode**- -
nation at test goes w»8ajr;»ft»*. Jto ?*'»-; v :
visas part of Hie book ne Uys it down

{KKitirely that the. igneous itoorgr itMiffl
FSMibleone, &B*'£rQeladeaare -valsiiaf isjeo- ^
fion formed by the i«filtratjo«» of sDuated ?
waters caro'Ing fee metala -alao in. eolation/'
a&d he deBenbefethe theoty «a one which «mi
to prove that reefs with their metaHiferoas
contents were 'thrown out in * molten state
from lie Interior of -Che earth.' This is
apparently the 'purely Igneoua theory «I iode
formation' which, he e»«L''Je»«Btentb4BO*n
vow belcnod Ioad«ano8,what nnfortnaJely for
the argument 'scientist* (3 we except Roaalasui
itiBCfeuy on the origin and formation of ^quartz
xeefe) never have advanced it, and they;, cer
tainly do not now.. The igneous theory really
Impliee the deposition of the. metallic contents
at lodes by condensation or sublimation.
Jlr, Johnson does not seem to be
aware of thia, as there ia no re
ference to it in hia work, and It ia
axjte as capable of explaining some of
the objections h& rai&es to the igaeous theory
SB it is certain that the infiltration theory trill
sot apply to all loden. The fact is the diversi
fied character of lodes leads to the 'inference
that several agencies were at work in their for
mation, and the best modern authorities con
sider that some lodes have an jgaeoua and
others an aqueous origin Ia order ttf make
Ids theory of universal formation of Ioda»--»y
infiltration fit in with geologic*! science, lift
Johnson goes back to the time when ' the
earth *u without form and void,' -and c»a
etracts a new system of geology u which he
makes volcanoes the origin of matamsrphtc
rocks, and *? probably the earlier Cumbrian and
guCirian strata.' He considers the 'first for
mation of mineral lodea ' took place 'probably
when t!-e dry land began to appear,' but does
not explain how the 'intrusive granites further
diBlocated aCd upheaved the slates' {which
had been formed aocordmg to, his theory by
volcanic mud &cd ash thrown np into
waters before this period. Mr. Johnson
cancer, believe in the great age of the
earlier geological periods, .and this apparently
sccocnts for his attempt to find Lyell and
Hseckel in error. But it is as Well to state that
the little book under notice is not intended to
be a geological work of reference. Tin- author a
remarks as to the formation of alluvial g£«* are
more to the point though not very novel. Me
believes in the existence of a silicate of gold
from which he considers moat of the metallio
gold has been derived, and atiopt3 the
theory of Daintree and othera in attributing
the formation of nuggety alluvial gold to the
flepoEiticn o! gold from salts held in solution.

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