Yerington times. [volume] (Yerington, Nev.) 1907-1932, 1912-05-11

make our task Of deciding easier.
Analyses are done in accordance
with the ordinary commercial method
and are unless otherwise stated, I'M
checked. They are reported III terms
OF per cent or parts per hundred.
The following terms are often re
ported and are defined as follows:
"lnsoluble residue is the residue
left after digcsting portion OF the
ore in hydrochloric and nitric acids.
1t consists in most cases OF silica
quartz and silicatcs combinations
OF bases with quartz.)
"Fcrric oxide and alumina" are fire.
quently reported urder one percent
/ age. and this means that the iron and
aluminium oxides are determined and
weighed together.
Lime" when reported as such
means calcium oxide
"Magnesia' when reported as such
means magnesium oxide
Soda when reported as such
means sodium oxide
The metals are usually reported in
percentages.
Gold Is reported ''as above IS per
ton in value" or below S. per ton in
value When present in amount less
than 002 ounces per ton il is report
ed As trace" when low grade gold
ore" is reported thi, signifies an ore
in value from S. 10 $40 per ton. \
medium grade gold ore" signifies an
ore in value between $40 and $50 per
ton y high grade gold ore" signi-
ieS an ore above $50 in value \
very low grade gold ore" signifies
gold ore from s. to $ per ton. Sill
yer Is reported in a similar manner.
Rocks are determined by the ordin-
AIRY field methods and when CORES
pondents desire determination by
thin section aud the micros1o ape
they may obtain this by sending fifty
cents 10 cover the cost OF the prepare
ton OF the thin section For most
+ purposes the field method al deter
mination gives sufficiently accurate
/ formation. Where the field method.
however. does not give satisfactory
results the laboratory make, the dc
termination from a thin section with
out charge
Rcports-Ail reports are rendered
by letter Approximately ten day, is
required from receipt OF sample until
Z report is sent out. In case that some
special Investigation i, required. con
>idcrably more time may clapsc he
/ tore the report j. sent.
The money available Tor the work
will not permit the maintenance OF
service throughout the year aud
consequently the following rule, have
been made: M material received Al.
ter May i, held until August 10
and after that date the necessary cx-
animation j. made and reports rem
dcrcd a. soon a. possible. Between
the dates uf January < and Nav
and August 10 and December : the
public will be given prompt service
samples and observation-disclosures
orS aud others are advised la send
III ample material Tor examina.
ton and to avoid sending specimens
as tar as practicable. II a ledge has
been found take one or more samples
by cutting each across the LEDGE ar
take general sample by combining
number OF chips taking from many
points along and acros, the ledgc
Mark each sample or specimen with
some number so that determination
may be easy The package should h,
plainly marked with name and adj.
dress OF the sender. \ letter giy;ny
information as TO locality and any
'pc'ihc directions should also be sem
Where rock idcnti6cations are dc.
sired send "irc,h"-that /, undecom.
posed material Very often it i, inn.
possible To determine a rock from the
mana specimen on account of il, de
composed or weathered condition
W mere only decomposed rock is avail.
ao'e send IN piece OF at least "6st
size"
ADDRESS all communications TO The
Mackay school Of Mines. Reno Nc
vada.
Mackay School Of Mines
Keno Nevada, Feb p, 1912