﻿404: 
  Kuzirian 
  — 
  Water 
  of 
  Crystallization 
  in 
  Sulphates. 
  

  

  ally 
  increased, 
  until 
  the 
  mixture 
  went 
  into 
  clear 
  fusion. 
  By 
  

   waving 
  a 
  Bunsen 
  flame 
  around 
  the 
  ignition 
  tube, 
  and 
  short 
  

   delivery 
  tubes, 
  the 
  condensed 
  moisture 
  was 
  volatilized. 
  After 
  

   the 
  apparent 
  disappearance 
  of 
  all 
  moisture, 
  the 
  remaining 
  

   traces 
  of 
  it 
  were 
  forced 
  into 
  the 
  sulphuric 
  acid 
  weighing 
  tubes 
  

   by 
  a 
  more 
  rapid 
  current 
  of 
  dry 
  air, 
  while 
  continuing 
  the 
  heat- 
  

   ing 
  of 
  the 
  ignition 
  and 
  delivery 
  tubes 
  for 
  at 
  least 
  twenty 
  min- 
  

   utes. 
  After 
  this 
  period 
  the 
  heating 
  was 
  stopped, 
  while 
  a 
  rapid 
  

   current 
  of 
  dry 
  air 
  was 
  passed 
  for 
  about 
  ten 
  minutes. 
  The 
  

   weighing 
  tube 
  was 
  disconnected, 
  stoppered 
  with 
  the 
  glass 
  plugs 
  

   used 
  as 
  stoppers 
  in 
  the 
  first 
  weighing, 
  brought 
  as 
  nearly 
  as 
  

   possible 
  to 
  the 
  original 
  temperature 
  (by 
  setting 
  it 
  aside 
  for 
  a 
  

   few 
  moments), 
  wiped 
  around 
  with 
  a 
  filter 
  paper, 
  and 
  weighed. 
  

   The 
  gain 
  in 
  weight 
  of 
  the 
  weighing 
  tube 
  was 
  recorded. 
  After 
  

   disconnecting 
  the 
  weighing 
  tube 
  from 
  the 
  ignition 
  tube, 
  

   the 
  delivery 
  tube 
  leading 
  into 
  the 
  ignition 
  tube 
  was 
  plugged 
  

   carefully, 
  to 
  avoid 
  any 
  moisture. 
  The 
  boat 
  was 
  taken 
  out 
  while 
  

   rather 
  hot, 
  cooled 
  in 
  a 
  desiccator 
  over 
  sulphuric 
  acid 
  and 
  

   weighed, 
  and 
  the 
  loss 
  in 
  weight 
  was 
  recorded. 
  It 
  was 
  found 
  

   that 
  if 
  the 
  procedure 
  was 
  carried 
  out 
  with 
  the 
  utmost 
  care, 
  

   observing 
  all 
  the 
  precautions, 
  the 
  loss 
  in 
  weight 
  of 
  the 
  porce- 
  

   lain 
  boat, 
  within 
  experimental 
  error, 
  corresponded 
  to 
  the 
  gain 
  

   in 
  weight 
  of 
  the 
  sulphuric 
  acid 
  tube, 
  and 
  this 
  corresponded 
  

   closely 
  to 
  the 
  theory 
  for 
  water 
  in 
  the 
  crystallized 
  sulphates. 
  

   Repeated 
  fusions 
  of 
  the 
  contents 
  of 
  the 
  boat 
  did 
  not 
  occasion 
  

   any 
  further 
  loss 
  in 
  weight, 
  thus 
  proving 
  that 
  under 
  the 
  condi- 
  

   tions 
  there 
  is 
  no 
  loss 
  of 
  sulphur 
  trioxide. 
  

  

  The 
  sulphuric 
  acid 
  weighing 
  tube 
  used 
  was 
  a 
  side-neck 
  

   U-tube 
  filled 
  with 
  glass 
  beads 
  and 
  the 
  ends 
  of 
  the 
  

   large 
  tube 
  were 
  sealed. 
  The 
  rubber 
  connecters 
  were 
  

   air 
  tight 
  so 
  that 
  the 
  weighing 
  tubes 
  would 
  not 
  gain 
  in 
  

   weight 
  over 
  night. 
  It 
  is 
  desirable 
  that 
  the 
  sulphuric 
  

   acid 
  in 
  the 
  drying 
  apparatus 
  and 
  in 
  the 
  weighing 
  tube 
  

   should 
  have 
  the 
  same 
  absorbing 
  power 
  ; 
  for 
  this 
  reason 
  the 
  sul- 
  

   phuric 
  acid 
  in 
  the 
  weighing 
  tube 
  was 
  changed 
  after 
  every 
  

   four 
  determinations. 
  

  

  The 
  determination 
  of 
  the 
  water 
  of 
  crystallization 
  in 
  copper 
  

   sulphate, 
  and 
  in 
  other 
  sulphates, 
  was 
  carried 
  out 
  under 
  the 
  

   conditions 
  cited 
  above, 
  with 
  special 
  precaution 
  to 
  avoid 
  loss 
  by 
  

   decrepitation 
  of 
  the 
  salt 
  while 
  yielding 
  its 
  water. 
  After 
  mixing 
  

   the 
  sulphate 
  well 
  with 
  sodium 
  tungstate, 
  another 
  portion 
  of 
  

   the 
  flux 
  was 
  put 
  upon 
  the 
  surface 
  of 
  the 
  mixture 
  to 
  form 
  a 
  

   trap, 
  and 
  thus 
  avoid 
  mechanical 
  loss, 
  and 
  the 
  mixture 
  was 
  

   heated 
  with 
  utmost 
  care 
  for 
  a 
  long 
  time 
  at 
  a 
  temperature 
  not 
  

   exceeding 
  70° 
  centigrade. 
  Following 
  are 
  some 
  of 
  the 
  results 
  

   obtained 
  with 
  various 
  sulphates 
  : 
  

  

  