﻿274: 
  A. 
  M. 
  Mayer— 
  On 
  the 
  Flotation 
  of 
  

  

  On 
  the 
  determination 
  of 
  the 
  surface 
  tension 
  of 
  a 
  solution 
  of 
  

   sodium 
  chloride 
  of 
  a 
  density 
  of 
  12. 
  

  

  A 
  wire 
  of 
  platinum 
  T 
  4 
  ff 
  mm 
  thick 
  made 
  into 
  a 
  ring 
  5'04 
  cm 
  in 
  

   diameter, 
  and 
  provided 
  with 
  a 
  wire 
  yoke 
  supporting 
  a 
  brass 
  

   cup, 
  floats 
  readily 
  on 
  water. 
  If 
  we 
  ascertain 
  the 
  weight 
  per 
  

   centimeter 
  required 
  to 
  force 
  the 
  ring 
  through 
  the 
  surface 
  of 
  

   the 
  water, 
  and 
  subtract 
  from 
  this 
  weight 
  the 
  upward 
  hydro- 
  

   static 
  pressure 
  on 
  a 
  centimeter 
  of 
  the 
  ring 
  we 
  will 
  have 
  a 
  quan- 
  

   tity 
  which, 
  compared 
  with 
  a 
  similarly 
  determined 
  quantity, 
  

   when 
  the 
  ring 
  is 
  placed 
  on 
  the 
  solution 
  of 
  sodium 
  chloride, 
  

   will 
  give 
  the 
  relative 
  surface 
  tensions 
  of 
  water 
  and 
  of 
  the 
  solu- 
  

   tion. 
  The 
  following 
  experiments 
  were 
  made 
  with 
  the 
  ring 
  on 
  

   water 
  : 
  

  

  Diameter 
  of 
  axis 
  of 
  ring 
  5 
  •04 
  cm 
  . 
  

  

  Circumference 
  of 
  axis 
  of 
  ring 
  15*83 
  cm 
  . 
  

  

  Temperature 
  of 
  water 
  and 
  of 
  salt 
  

  

  solution 
  16°. 
  

  

  W. 
  

  

  2-248 
  

   •297 
  

   •291 
  

   •233 
  

  

  •285 
  

   •287 
  

  

  2-273 
  = 
  mean. 
  

   W 
  

  

  = 
  -14358 
  = 
  w 
  ; 
  w—p 
  = 
  -14233 
  

  

  circ 
  

  

  The 
  following 
  were 
  the 
  results 
  of 
  the 
  experiments 
  made 
  with 
  

   the 
  platinum 
  ring 
  on 
  the 
  solution 
  of 
  sodium 
  chloride. 
  

  

  W 
  2-538 
  _ 
  

  

  -— 
  , 
  = 
  = 
  -1603=w 
  

  

  circ 
  15-83 
  

  

  w—p='lQ03 
  — 
  "0016 
  = 
  -1587 
  

  

  Taking 
  -0772 
  as 
  the 
  surface 
  tension 
  of 
  water, 
  we 
  have 
  

   for 
  the 
  surface 
  tension 
  of 
  the 
  solution 
  of 
  sodium 
  chloride 
  

  

  Tt^oqX 
  -0772 
  = 
  -0860. 
  Frankenheim* 
  gives 
  -0840 
  at 
  19°, 
  which 
  

  

  reduced 
  by 
  Brunner's 
  formula 
  to 
  16° 
  becomes 
  -0844. 
  

  

  A 
  peculiar 
  phenomenon 
  was 
  observed 
  during 
  the 
  experi- 
  

   ments 
  to 
  find 
  the 
  weight 
  necessary 
  to 
  sink 
  the 
  ring 
  in 
  the 
  

   sodium 
  chloride 
  solution. 
  There 
  was 
  observed 
  a 
  gradual 
  

  

  * 
  Cohasionslehre, 
  Breslau, 
  1835. 
  

  

  