Chapter III: Lode or Reef Prospecting

Likeliest localities for reefs--Similarity of indications of
minerals--Where first prospecting is done--A practical
example--Ironstone “blows”--Their true origin--Igneous theory
untenable--Usual trend of lodes in Australia--Exceptions
to the rule--Instances of rich deposits apart from
lodes--Sinuosity of lodes--How to trace lodes
demonstrated--Examine all indications--How to recognise gold,
silver, copper, tin--How to ascertain their value--Caution
in sinking--Where to prospect in case of parallel lodes--Usual
underlie in Australia--Size of prospecting shaft--Tip for
mullock--How to distinguish gold from pyrites or
mica--Estimating value from prospect--How to pan--An
amalgamating assay method--Author’s device when antimony
present--Battery, best test--Silver and tin indications--Lode
tin, stream tin, difficulty of recognising tin--Lode tin
always near granite--Minerals often mistaken for tin--How
to discriminate--Tin in Westralia pp. 22-33

CHAPTER IV

THE GENESIOLOGY OF GOLD

(AURIFEROUS LODES)

Igneous theory formerly strongly upheld--Quotation from
Rosales--His arguments combated--Hydro-thermal action--Its
evidences in New Zealand--Professor Lobley’s theory--Author’s
deposition theory confirmed--Later works--Conclusions of
Le Conte--Metamorphic slates and earlier Silurian strata
theory--Format ion of mineral lodes--What was gold
originally?--Metal or metallic salt--Silicate hypothesis
preferred--Explanation of sulphides and silicates of
gold--Bischof’s interesting experiment--Skey’s and other
deposition experiments--How gold took its metallic form--The
Comstock lode--Occurrence of gold in shutes explained--Why
lode junctions are usually rich--Cox’s theory--Instances
of lodes re-forming--Gold as natural sulphide--Newbery’s
theory of gold in pyritous lodes--Probable occurrence in
pyritous ores as sulphide pp. 34-47

CHAPTER V

THE GENESIOLOGY OF GOLD

(AURIFEROUS DRIFTS)

Derivation and occurrence--Old diggers’ “growing”
theory--Deposition experiment illustrating nature--Denudation
of quartz lodes theory--Examples of its probability--Nuggets
require other explanation--Deposition, most rational
theory--Usual alluvial theory combated--Daintree’s and
Wilkinson’s deposition experiments--Spondulix and Lothair
nuggets--Newbery’s deposition experiments--Nugget form
explained--Author’s experiments in manufacture of golden
quartz--Extract from author’s “Deposition of
Gold”--Remarkable nugget--Reason of superiority of alluvial
gold pp. 48-58