﻿1875.] 
  Liquation 
  of 
  Alloys 
  of 
  Silver 
  and 
  Copper. 
  435 
  

  

  of 
  1 
  dwt. 
  in 
  the 
  pound, 
  or 
  the 
  ^-J^ 
  part 
  ; 
  and 
  as 
  4;he 
  coins 
  were 
  cut 
  

   in 
  a 
  double 
  row 
  down 
  each 
  strap, 
  from 
  top 
  to 
  bottom, 
  it 
  followed 
  that 
  

   every 
  coin 
  at 
  one 
  end 
  of 
  a 
  transverse 
  diameter 
  touched 
  the 
  edge 
  of 
  the 
  

   strap, 
  or 
  the 
  coarser 
  metal, 
  and 
  at 
  the 
  other 
  end 
  of 
  the 
  same 
  diameter 
  

   touched 
  the 
  interior 
  or 
  finer 
  metal. 
  

  

  Thus 
  the 
  different 
  parts 
  of 
  coins 
  composed 
  of 
  standard 
  silver 
  vary 
  

   essentially 
  in 
  fineness 
  at 
  different 
  points 
  of 
  their 
  circumference. 
  If 
  we 
  

   were 
  to 
  call 
  those 
  parts 
  of 
  the 
  coins 
  north 
  and 
  south 
  which, 
  before 
  they 
  

   were 
  cut, 
  lay 
  in 
  the 
  direction 
  of 
  the 
  length 
  of 
  the 
  strap, 
  and 
  those 
  at 
  

   right 
  angles 
  thereto 
  east 
  and 
  west, 
  it 
  would 
  give 
  a 
  correct 
  idea 
  of 
  this 
  

   i 
  peculiarity 
  to 
  say 
  that 
  there 
  is 
  no 
  essential 
  difference 
  between 
  the 
  north 
  

   and 
  south 
  sides 
  of 
  the 
  piece, 
  but 
  a 
  considerable 
  one 
  between 
  the 
  east 
  

   and 
  west, 
  frequently 
  amounting 
  to 
  j 
  dwt. 
  in 
  the 
  lb., 
  and 
  in 
  coins 
  cut 
  

   from 
  certain 
  portions 
  of 
  each 
  strap 
  to 
  more 
  than 
  1 
  dwt., 
  or 
  ^j-, 
  some- 
  

   times 
  even 
  to 
  2 
  dwts. 
  From 
  this 
  circumstance 
  it 
  is 
  evident 
  that 
  assays 
  

   taken 
  in 
  the 
  manner 
  formerly 
  used 
  for 
  the 
  pyx 
  examination 
  of 
  coins 
  

   in 
  some 
  of 
  the 
  Indian 
  Mints, 
  by 
  flattening 
  one 
  edge 
  of 
  a 
  coin 
  and 
  

   cutting 
  off 
  a 
  part 
  of 
  it 
  for 
  trial, 
  may 
  often 
  lead 
  to 
  its 
  unjust 
  condem- 
  

   nation 
  ; 
  and 
  when 
  the 
  whole 
  work 
  of 
  a 
  mint 
  of 
  many 
  thousands 
  of 
  

   pounds 
  value 
  is 
  liable 
  to 
  rejection 
  in 
  consequence 
  of 
  an 
  unfavourable 
  

   report 
  upon 
  individual 
  coins, 
  which 
  more 
  than 
  once 
  occurred 
  in 
  Madras, 
  

   it 
  is 
  obvious 
  that 
  a 
  more 
  correct 
  method 
  of 
  ascertaining 
  the 
  average 
  

   fineness 
  of 
  the 
  whole 
  outturn 
  is 
  very 
  desirable. 
  

  

  For 
  this 
  purpose 
  it 
  was 
  suggested 
  that 
  the 
  samples 
  for 
  assay 
  should 
  

   be 
  taken 
  from 
  the 
  centre 
  of 
  each 
  coin, 
  or 
  by 
  a 
  ring 
  representing 
  the 
  

   whole 
  circumference. 
  But 
  the 
  true 
  average 
  fineness 
  of 
  the 
  whole 
  of 
  a 
  

   large 
  silver 
  coinage 
  is 
  much 
  more 
  easily 
  and 
  better 
  arrived 
  at 
  by 
  taking 
  

   out 
  a 
  large 
  number 
  of 
  the 
  coins 
  indiscriminately, 
  and 
  having 
  melted 
  

   them 
  together 
  into 
  a 
  perfectly 
  uniform 
  and 
  homogeneous 
  compound, 
  pro- 
  

   ceed 
  according 
  to 
  the 
  following 
  method, 
  which 
  was 
  latterly 
  adopted 
  in 
  

   India. 
  

  

  While 
  the 
  representative 
  coins 
  are 
  undergoing 
  fusion, 
  a 
  portion 
  is 
  taken 
  

   out 
  in 
  its 
  fluid 
  homogeneous 
  condition 
  and 
  granulated 
  by 
  pouring 
  into 
  

   cold 
  water. 
  A 
  number 
  of 
  the 
  granules 
  are 
  then 
  selected 
  for 
  assay, 
  and 
  

   after 
  being 
  carefully 
  dried 
  and 
  weighed, 
  are 
  wholly 
  (that 
  is, 
  each 
  granule 
  

   in 
  its 
  integral 
  state) 
  dissolved 
  in 
  acid. 
  The 
  silver 
  contained 
  in 
  them 
  is 
  

   afterwards 
  separated 
  as 
  a 
  chloride, 
  and 
  estimated 
  in 
  the 
  usual 
  way, 
  the 
  

   fineness 
  of 
  the 
  mass 
  being 
  calculated 
  by 
  a 
  comparison 
  of 
  the 
  weight 
  of 
  

   pure 
  silver 
  thus 
  ascertained 
  with 
  the 
  original 
  weight 
  of 
  the 
  granules. 
  

  

  "When 
  carefully 
  prepared, 
  as 
  above 
  described, 
  there 
  is 
  a 
  near 
  agreement 
  

   in 
  the 
  finenesses 
  of 
  the 
  single 
  granules, 
  which 
  rarely 
  differ 
  from 
  the 
  mean 
  

   fineness 
  of 
  the 
  metal 
  so 
  much 
  as 
  two 
  thousandths 
  when 
  individually 
  

   assayed, 
  more 
  than 
  half 
  of 
  them 
  being 
  found 
  within 
  one 
  thousandth, 
  

   and 
  the 
  average 
  of 
  a 
  number 
  consequently 
  very 
  elose 
  to 
  the 
  truth. 
  

  

  