﻿462 
  Wells 
  and 
  Foote 
  — 
  Certain 
  Double 
  Halogen 
  

  

  hydrochloric 
  acid 
  to 
  a 
  nearly 
  saturated 
  warm 
  solution 
  of 
  the 
  

   salt 
  in 
  dilute 
  hydrochloric 
  acid. 
  E 
  was 
  obtained 
  from 
  a 
  very 
  

   strong 
  hydrochloric 
  acid 
  solution 
  formed 
  by 
  passing 
  a 
  rapid 
  

   current 
  of 
  hydrogen 
  chloride 
  gas 
  into 
  the 
  solution 
  as 
  it 
  cooled. 
  

   F 
  was 
  obtained 
  by 
  recrystallizing 
  the 
  salt 
  from 
  hydrochloric 
  

   acid 
  which 
  was 
  kept 
  as 
  dilute 
  as 
  it 
  could 
  be 
  without 
  producing 
  

   the 
  basic 
  double 
  salt 
  to 
  be 
  described 
  beyond. 
  G 
  was 
  a 
  product 
  

   obtained 
  by 
  recrystallizing 
  the 
  salt 
  from 
  a 
  mixture 
  of 
  equal 
  

   volumes 
  of 
  dilute 
  hydrochloric 
  acid 
  and 
  alcohol. 
  

  

  The 
  two 
  products 
  obtained 
  from 
  concentrated 
  hydrochloric 
  

   acid 
  solution 
  had 
  a 
  pale 
  yellow 
  color 
  while 
  the 
  others 
  were 
  all 
  

   white. 
  The 
  crystals 
  were 
  usually 
  well-formed 
  six-sided 
  plates 
  

   which 
  showed 
  no 
  definite 
  optical 
  properties. 
  

  

  The 
  analyses 
  of 
  the 
  various 
  products 
  are 
  as 
  follows 
  : 
  

  

  Rubidium. 
  Antimony. 
  Chlorine. 
  

  

  A 
  39-23 
  23-85 
  37-01 
  

  

  B 
  39-23 
  23-84 
  36*99 
  

  

  C 
  23-91 
  

  

  D 
  39-25 
  23-98 
  

  

  E 
  . 
  . 
  39-31 
  23 
  89 
  

  

  F 
  39-03 
  23-86 
  

  

  G 
  39-11 
  23-90 
  

  

  Average 
  ..39-19 
  23-89 
  37*00 
  

  

  Method 
  of 
  analysis. 
  — 
  For 
  the 
  determination 
  of 
  antimony 
  

   and 
  rubidium, 
  a 
  portion 
  of 
  about 
  one-half 
  a 
  gram 
  was 
  dis- 
  

   solved 
  in 
  water 
  and 
  enough 
  hydrochloric 
  acid 
  to 
  prevent 
  anti- 
  

   mony 
  oxy 
  chloride 
  from 
  precipitating. 
  The 
  solution 
  was 
  heated 
  

   to 
  boiling 
  and 
  hydrogen 
  sulphide 
  passed 
  in. 
  The 
  solution 
  was 
  

   then 
  cooled 
  and 
  the 
  antimony 
  sulphide 
  filtered 
  on 
  a 
  Gooch 
  

   crucible 
  and 
  washed 
  with 
  water 
  and 
  with 
  alcohol. 
  The 
  cruci- 
  

   ble 
  was 
  then 
  slowly 
  heated 
  to 
  230° 
  and 
  cooled 
  in 
  an 
  oven 
  filled 
  

   with 
  carbonic 
  acid. 
  The 
  precipitate 
  was 
  weighed 
  as 
  Sb 
  2 
  S 
  3 
  . 
  

   The 
  filtrate 
  containing 
  rubidium 
  was 
  evaporated 
  with 
  sulphuric 
  

   acid 
  and 
  the 
  residue 
  ignited 
  in 
  a 
  stream 
  of 
  air 
  containing 
  

   ammonia 
  and 
  weighed 
  as 
  Kb 
  2 
  S0 
  4 
  . 
  Chlorine 
  was 
  determined 
  

   by 
  dissolving 
  a 
  separate 
  portion 
  in 
  water 
  acidified 
  with 
  tartaric 
  

   and 
  nitric 
  acids 
  and 
  precipitating 
  with 
  silver 
  nitrate. 
  This 
  

   was 
  allowed 
  to 
  stand 
  for 
  some 
  time 
  and 
  the 
  precipitate 
  was 
  then 
  

   collected 
  on 
  a 
  Gooch 
  crucible 
  and 
  weighed. 
  The 
  methods 
  

   used 
  are 
  almost 
  identical 
  with 
  those 
  of 
  Wheeler. 
  

  

  The 
  accuracy 
  of 
  the 
  antimony 
  determination 
  was 
  checked 
  in 
  

   the 
  following 
  manner. 
  The 
  salt 
  Cs 
  3 
  Sb 
  2 
  Cl 
  9 
  was 
  prepared 
  from 
  

   very 
  pure 
  materials 
  and 
  carefully 
  recrystallized 
  and 
  antimony 
  

   determined 
  by 
  the 
  above 
  method. 
  The 
  per 
  cent 
  of 
  antimony 
  

   is 
  nearly 
  the 
  same 
  as 
  in 
  the 
  rubidium 
  antimony 
  salt 
  under 
  con- 
  

   sideration. 
  The 
  following 
  results 
  were 
  obtained 
  : 
  

  

  