﻿Gooch 
  and 
  Kobayashi 
  — 
  Electrolytic 
  Analysis. 
  391 
  

  

  Fig. 
  1. 
  

  

  Art. 
  XXXVT. 
  — 
  Electrolytic 
  Analysis 
  with 
  Small 
  Platinum 
  

   Electrodes; 
  by 
  F. 
  A. 
  Gooch 
  and 
  Matsusuke 
  Kobayashi. 
  

  

  [Contributions 
  from 
  the 
  Kent 
  Chemical 
  Laboratory 
  of 
  Yale 
  Univ. 
  — 
  cclxxxvii.] 
  

  

  In 
  a 
  former 
  article 
  from 
  this 
  laboratory* 
  it 
  was 
  shown 
  that 
  

   certain 
  processes 
  of 
  electrolytic 
  analysis 
  may 
  be 
  carried 
  out 
  

   successfully 
  with 
  the 
  aid 
  of 
  small 
  platinum 
  electrodes 
  of 
  light 
  

   weight 
  and 
  a 
  weighable 
  cell, 
  any 
  difficulty 
  due 
  to 
  the 
  detach- 
  

   ment 
  of 
  particles 
  of 
  material 
  deposited 
  at 
  high 
  

   current 
  density 
  upon 
  the 
  small 
  electrode 
  surfaces 
  

   being 
  overcome 
  by 
  drawing 
  off 
  the 
  residual 
  liquid 
  

   through 
  a 
  small 
  filtering 
  tube 
  which 
  was 
  finally 
  

   weighed 
  with 
  the 
  electrodes 
  and 
  the 
  electrolytic 
  

   cell. 
  The 
  feasibility 
  of 
  the 
  process 
  was 
  demon- 
  

   strated 
  in 
  determinations 
  of 
  copper 
  and 
  nickel, 
  

   taken 
  in 
  the 
  form 
  of 
  sulphates, 
  from 
  solutions 
  of 
  

   small 
  volume. 
  The 
  results 
  of 
  the 
  determinations 
  

   were 
  good, 
  but 
  the 
  criticism 
  has 
  been 
  madef 
  that 
  

   the 
  use 
  of 
  solutions 
  of 
  the 
  small 
  volume 
  (about 
  

   15 
  cm 
  3 
  ) 
  appropriate 
  to 
  the 
  cell 
  which 
  was 
  employed 
  

   is 
  impracticable. 
  Although 
  the 
  former 
  experi- 
  

   mental 
  results 
  show 
  that 
  such 
  a 
  conclusion 
  is 
  

   unwarranted, 
  we 
  have 
  thought 
  it 
  desirable 
  to 
  test 
  

   the 
  small 
  electrodes 
  in 
  an 
  apparatus 
  modified 
  to 
  

   permit 
  the 
  use 
  of 
  volumes 
  of 
  solution 
  which 
  are 
  

   comparable 
  with 
  those 
  ordinarily 
  employed 
  in 
  

   analysis. 
  

  

  In 
  the 
  experiments 
  to 
  be 
  described, 
  the 
  rotating 
  electrode 
  

   (fig. 
  1) 
  was 
  made 
  of 
  a 
  small 
  piece 
  of 
  platinum 
  gauze 
  (1'2 
  CU1 
  

   square) 
  into 
  the 
  central 
  meshes 
  of 
  which 
  the 
  

   tapered 
  end 
  of 
  a 
  lead 
  glass 
  rod 
  was 
  fused. 
  The 
  

   electrical 
  connection 
  between 
  the 
  gauze 
  and 
  the 
  

   metal 
  shaft 
  of 
  the 
  motor, 
  which 
  formed 
  a 
  part 
  of 
  

   the 
  electrical 
  circuit, 
  was 
  made 
  by 
  means 
  of 
  a 
  

   doubled 
  and 
  twisted 
  platinum 
  wire, 
  003 
  cm 
  in 
  diam- 
  

   eter, 
  wound 
  about 
  the 
  glass 
  rod 
  and 
  held 
  to 
  the 
  

   shaft 
  by 
  means 
  of 
  a 
  twist 
  of 
  copper 
  wire 
  (see 
  

   fig. 
  3). 
  The 
  stationary 
  electrode 
  was 
  a 
  strip 
  of 
  

   thin 
  platinum 
  foil 
  (5 
  cm 
  x 
  0*5 
  cm 
  ) 
  welded 
  to 
  the 
  con- 
  

   necting 
  wire 
  by 
  means 
  of 
  which 
  it 
  was 
  hung 
  to 
  

   the 
  side 
  of 
  a 
  thin 
  glass 
  beaker 
  of 
  about 
  120 
  cm 
  3 
  

   capacity. 
  

  

  The 
  small 
  filtering 
  tube 
  (fig. 
  2) 
  was 
  made 
  by 
  

   fusing 
  the 
  flared 
  end 
  of 
  a 
  lead 
  glass 
  tube 
  to 
  a 
  

   little 
  disc 
  of 
  platinum 
  gauze, 
  and 
  coating 
  the 
  disc 
  

   with 
  a 
  filtering 
  mat 
  by 
  dipping 
  it 
  in 
  an 
  emulsion 
  

  

  * 
  Gooch 
  and 
  Burdick, 
  this 
  Journal, 
  xxxiv, 
  109, 
  1912. 
  

   fFresenius, 
  Zeitschr. 
  anal. 
  Chem., 
  lii, 
  209, 
  1913. 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XLTIT, 
  No. 
  257.— 
  May, 
  1917. 
  

  

  27 
  

  

  electrolytic 
  

  

  Fig. 
  2. 
  

  

  