﻿Chemistry 
  and 
  Physics. 
  645 
  

  

  2. 
  Volumetric 
  Determination 
  of 
  Fluorine. 
  — 
  Alfred 
  Greef 
  

   has 
  devised 
  a 
  new 
  volumetric 
  method 
  for 
  the 
  determination 
  of 
  

   fluorine, 
  which 
  promises 
  to 
  be 
  important, 
  since 
  heretofore 
  the 
  

   determination 
  of 
  this 
  element 
  has 
  presented 
  many 
  difficulties. 
  

   Thus 
  far 
  the 
  method 
  has 
  been 
  worked 
  out 
  only 
  for 
  compounds 
  

   soluble 
  in 
  water. 
  It 
  is 
  based 
  upon 
  the 
  fact 
  that 
  in 
  a 
  neutral 
  solu- 
  

   tion 
  of 
  sodium 
  fluoride 
  the 
  addition 
  of 
  ferric 
  chloride 
  produces 
  a 
  

   precipitate 
  of 
  " 
  ferric 
  cryolite," 
  Na 
  3 
  FeF 
  6 
  , 
  which 
  does 
  not 
  react 
  

   with 
  potassium 
  sulphocyanide 
  to 
  produce 
  a 
  red 
  color. 
  The 
  end 
  

   reaction 
  is 
  not 
  sharp, 
  however, 
  except 
  under 
  special 
  conditions. 
  

   The 
  solution 
  must 
  be 
  neutral 
  to 
  phenolphthalein. 
  A 
  volume 
  of 
  

   25 
  cc 
  in 
  an 
  Erlenmeyer 
  flask 
  is 
  recommended. 
  Then 
  20 
  s 
  of 
  pure 
  

   sodium 
  chloride 
  and 
  I 
  s 
  of 
  potassium 
  sulphocyanide 
  are 
  added 
  and 
  

   it 
  is 
  titrated 
  with 
  a 
  ferric 
  chloride 
  solution, 
  made 
  from 
  the 
  com- 
  

   mercial 
  salt 
  and 
  containing 
  such 
  an 
  amount 
  of 
  iron 
  that 
  l 
  cc 
  is 
  

   equivalent 
  to 
  0'01 
  g 
  of 
  NaF, 
  until 
  a 
  pale 
  yellow 
  color 
  is 
  produced. 
  

   Then 
  10 
  cc 
  each 
  of 
  alcohol 
  and 
  ether 
  are 
  added, 
  the 
  liquid 
  is 
  shaken 
  

   up 
  once 
  while 
  the 
  flask 
  is 
  open, 
  then 
  a 
  stopper 
  is 
  put 
  in 
  and 
  the 
  

   liquid 
  is 
  shaken 
  thoroughly 
  until, 
  after 
  further 
  addition 
  of 
  ferric 
  

   chloride, 
  the 
  ether 
  layer 
  no 
  longer 
  loses 
  its 
  red 
  color 
  upon 
  shaking 
  

   and 
  standing. 
  Mixtures 
  of 
  sodium 
  fluoride 
  with 
  acid 
  sodium 
  

   fluoride 
  and 
  sodium 
  silicon 
  fluoride 
  may 
  be 
  analyzed 
  by 
  first 
  

   titrating 
  in 
  a 
  platinum 
  dish, 
  hot, 
  with 
  decinormal 
  sodium 
  hydrox- 
  

   ide, 
  with 
  phenolphthalein 
  as 
  indicator, 
  thus 
  measuring 
  the 
  effect 
  

   of 
  the 
  two 
  other 
  things 
  together, 
  then 
  determining 
  the 
  total 
  

   sodium 
  fluoride 
  as 
  previously 
  described. 
  In 
  another 
  portion 
  the 
  

   acid 
  fluoride 
  is 
  determined 
  by 
  titration 
  with 
  sodium 
  hydroxide 
  

   after 
  the 
  addition 
  of 
  potassium 
  chloride 
  and 
  alcohol 
  amounting 
  to 
  

   about 
  one-half 
  of 
  the 
  final 
  volume. 
  The 
  test 
  analyses 
  given 
  by 
  

   the 
  author 
  show 
  very 
  satisfactory 
  results, 
  both 
  for 
  sodium 
  fluo- 
  

   ride 
  alone 
  and 
  for 
  the 
  mixtures. 
  — 
  Berichte, 
  xlvi, 
  2511. 
  h. 
  l. 
  w. 
  

  

  3. 
  The 
  Behavior 
  of 
  Hydrogen 
  totoards 
  Palladium. 
  — 
  Since 
  there 
  

   are 
  conflicting 
  statements 
  in 
  the 
  literature 
  in 
  regard 
  to 
  the 
  volume 
  

   of 
  hydrogen 
  absorbed 
  by 
  palladium 
  at 
  low 
  temperatures, 
  Gtttbier, 
  

   Gebhardt, 
  and 
  Ottenstein 
  have 
  made 
  a 
  new 
  investigation 
  of 
  

   this 
  subject. 
  Using 
  spongy 
  palladium 
  which 
  had 
  been 
  prepared 
  

   very 
  carefully, 
  they 
  saturated 
  it 
  with 
  hydrogen 
  at 
  various 
  tem- 
  

   peratures, 
  then 
  after 
  removing 
  the 
  excess 
  of 
  hydrogen 
  by 
  means 
  

   of 
  a 
  current 
  of 
  carbon 
  dioxide, 
  they 
  drove 
  off 
  the 
  hydrogen 
  by 
  

   ignition 
  and 
  measured 
  it. 
  They 
  found 
  a 
  minimum 
  absorption 
  at 
  

   20° 
  C. 
  of 
  661 
  volumes 
  of 
  hydrogen, 
  which 
  increased 
  gradually 
  to 
  

   917 
  volumes 
  at 
  —50° 
  G, 
  and 
  which 
  increased 
  more 
  slowly 
  to 
  754 
  

   volumes 
  at 
  105° 
  C. 
  — 
  Berichte, 
  xlvi, 
  1453. 
  h. 
  l. 
  w. 
  

  

  4. 
  A 
  New 
  Era 
  in 
  Chemistry 
  ; 
  by 
  Harry 
  C. 
  Jones. 
  12mo, 
  

   pp. 
  326. 
  New 
  York, 
  1913 
  (D. 
  Van 
  Nostrand 
  Gompany). 
  Price 
  

   $2.00 
  net. 
  — 
  This 
  work 
  gives 
  an 
  account 
  of 
  the 
  more 
  important 
  

   developments 
  in 
  general 
  chemistry 
  during 
  the 
  last 
  quarter 
  of 
  a 
  

   century 
  — 
  the 
  development, 
  in 
  fact, 
  of 
  modern 
  physical 
  chemistry. 
  

   The 
  discussion 
  necessarily 
  includes 
  some 
  account 
  of 
  older 
  theories 
  

   in 
  order 
  that 
  the 
  recent 
  work 
  may 
  be 
  more 
  thoroughly 
  explained. 
  

  

  