﻿Diamagnetic 
  and 
  Weakly 
  Magnetic 
  Substances. 
  

   Table 
  IV. 
  

  

  445 
  

  

  White 
  wood 
  

  

  Holly 
  

  

  Plain 
  Oak 
  .. 
  

  

  Tulip 
  

  

  Cedar 
  

  

  57-5927 
  

   57-5934 
  

  

  60-9816 
  

   60-9812 
  

  

  61-6701 
  

   61-6704 
  

  

  69 
  0779 
  

   69-0779 
  

  

  581218 
  

  

  58-1210 
  

  

  Moan 
  

   Vv 
  

  

  Po- 
  

  

  57-5930 
  

  

  57-5957 
  

  

  609814 
  

  

  60-9357 
  

  

  61-6704 
  

  

  61-6766 
  

  

  69 
  0779 
  

  

  69 
  0863 
  

  

  581214 
  

  

  58 
  1239 
  

  

  p= 
  

  

  Po— 
  Pi 
  f-6. 
  I 
  W. 
  

  

  •0029 
  

   •0045 
  

   •0064 
  

   •0086 
  

   •0027 
  

  

  5-09 
  

  

  5-07 
  

  

  504 
  

  

  5-08 
  

  

  5 
  03 
  

  

  •462 
  

  

  •499 
  

  

  •449 
  

  

  /cxlO" 
  

  

  -•18 
  

  

  •26 
  

  

  -•36 
  

  

  476 
  --51 
  

  

  •479 
  

  

  -•16 
  

  

  Pi- 
  

  

  73-6900 
  

  

  Po- 
  Vx 
  

  

  72 
  9620 
  

  

  •0002 
  

   0034 
  

  

  F 
  = 
  

  

  -Po+8. 
  

   •7314 
  

  

  I 
  =4-54 
  

   1= 
  -427 
  

  

  H. 
  

  

  3,700 
  

  

  These 
  results 
  show_, 
  in 
  general, 
  that 
  the 
  greater 
  the 
  density 
  

   of 
  the 
  wood 
  the 
  greater 
  is 
  the 
  coefficient 
  of 
  magnetic 
  suscep- 
  

   tibility. 
  

  

  Besides 
  these 
  quantitative 
  experiments 
  there 
  were 
  made 
  a 
  

   large 
  number 
  of 
  qualitative 
  experiments 
  upon 
  a 
  great 
  many 
  

   different 
  kinds 
  of 
  wood. 
  Only 
  one 
  kind 
  out 
  of 
  about 
  twenty 
  

   different 
  kinds 
  tried 
  proved 
  to 
  be 
  magnetic, 
  the 
  rest 
  were 
  

   diamagnetic 
  ; 
  the 
  exception 
  was 
  butternut. 
  

  

  There 
  has 
  been 
  in 
  the 
  past 
  a 
  difference 
  of 
  opinion 
  among 
  

   physicists 
  as 
  to 
  whether 
  diamagnetic 
  substances 
  are 
  or 
  are 
  

   not 
  less 
  susceptible 
  under 
  the 
  application 
  of 
  large 
  magnetizing 
  

   forces. 
  Most 
  of 
  the 
  earlier 
  experimenters, 
  among 
  them 
  

   Tyndall, 
  Joule, 
  and 
  Becquerel, 
  found 
  reason 
  to 
  believe 
  that 
  k 
  

   is 
  constant 
  for 
  diamagnetic 
  substances. 
  Plucker, 
  however, 
  

   believed 
  that 
  in 
  some 
  cases, 
  as 
  the 
  magnetizing 
  force 
  is 
  

   increased 
  the 
  coefficient 
  of 
  susceptibility 
  /c 
  for 
  diamagnetic 
  

   bodies 
  decreases 
  in 
  a 
  similar 
  way 
  as 
  in 
  iron. 
  Plucker 
  also 
  

   thought 
  he 
  observed 
  in 
  some 
  cases 
  an 
  increase 
  in 
  k 
  with 
  an 
  

   increase 
  in 
  the 
  magnetizing 
  force 
  up 
  to 
  a 
  certain 
  point, 
  after 
  

   that 
  a 
  decrease 
  ; 
  that 
  is, 
  for 
  a 
  certain 
  value 
  of 
  the 
  magnetizing 
  

   force 
  k 
  has 
  a 
  maximum. 
  Silow* 
  (1880) 
  published 
  results 
  

   which 
  indicate 
  that 
  k 
  for 
  ferric 
  chloride 
  increases 
  for 
  a 
  while 
  

  

  * 
  Wied. 
  Ann. 
  ii. 
  p. 
  324 
  (1880). 
  

   Phil. 
  Mag. 
  S. 
  5. 
  Yol. 
  45. 
  No. 
  276. 
  May 
  1898. 
  

  

  2H 
  

  

  