﻿316 
  Scientific 
  Intelligence. 
  

  

  the 
  authority 
  of 
  a 
  master 
  of 
  his 
  subject. 
  So 
  that 
  his 
  book, 
  

   notwithstanding 
  the 
  treatises 
  of 
  Ostwald 
  and 
  others 
  on 
  Physical 
  

   Chemistry, 
  seems 
  to 
  us, 
  in 
  the 
  excellence 
  of 
  its 
  arrangement, 
  the 
  

   clearness 
  of 
  its 
  style 
  and 
  the 
  thoroughness 
  of 
  its 
  subject-matter, 
  

   to 
  be 
  the 
  best 
  book 
  of 
  its 
  kind 
  which 
  has 
  yet 
  appeared. 
  Dr. 
  

   Palmer 
  deserves 
  especial 
  thanks 
  for 
  putting 
  the 
  book 
  so 
  admirably 
  

   into 
  its 
  English 
  dress. 
  Typographically 
  also, 
  the 
  book 
  is 
  a 
  credit 
  

   to 
  its 
  publishers. 
  g. 
  f. 
  b. 
  

  

  8. 
  Qualitative 
  Chemical 
  Analysis 
  of 
  Inorganic 
  Substa?ices, 
  

   as 
  practiced 
  in 
  Georgetown 
  College, 
  D. 
  C. 
  Short 
  4to, 
  pp. 
  61. 
  

   New 
  York, 
  1894 
  (American 
  Book 
  Company). 
  — 
  This 
  book 
  consists 
  

   of 
  a 
  series 
  of 
  tables 
  for 
  qualitative 
  analysis, 
  divided 
  into 
  four 
  

   sets. 
  The 
  first 
  is 
  on 
  Basic 
  Analysis, 
  the 
  second 
  on 
  Acid 
  Analysis, 
  

   the 
  third 
  on 
  Preliminary 
  Examination, 
  and 
  the 
  fourth 
  on 
  Solution 
  

   and 
  on 
  Special 
  treatment. 
  Though 
  in 
  the 
  main 
  following 
  well 
  

   established 
  authorities, 
  yet 
  there 
  is 
  some 
  originality 
  of 
  arrange- 
  

   ment 
  and 
  some 
  satisfactory 
  explanatory 
  matter 
  added 
  to 
  the 
  

   tables. 
  The 
  book 
  appears 
  to 
  have 
  been 
  prepared 
  with 
  consider- 
  

   able 
  care. 
  g. 
  f. 
  b. 
  

  

  9. 
  Double 
  refraction 
  of 
  Electric 
  loaves. 
  — 
  K. 
  Mack 
  by 
  inter- 
  

   posing 
  pieces 
  of 
  wood 
  between 
  Hertz's 
  well 
  known 
  parabolic 
  

   reflectors, 
  the 
  axes 
  of 
  which 
  are 
  inclined 
  to 
  each 
  other, 
  has 
  shown 
  

   that 
  electric 
  waves 
  can 
  be 
  doubly 
  refracted. 
  Most 
  specimens 
  of 
  

   wood 
  have 
  a 
  different 
  structure 
  along 
  the 
  direction' 
  of 
  the 
  fibres 
  

   from 
  that 
  perpendicular 
  to 
  this 
  direction, 
  and 
  accordingly 
  resem- 
  

   ble 
  in 
  this 
  respect 
  doubly 
  refracting 
  crystals 
  possessing 
  a 
  struc- 
  

   ture 
  parallel 
  to 
  their 
  optic 
  axis 
  different 
  from 
  that 
  at 
  right 
  

   angles 
  to 
  this 
  axis. 
  When 
  pieces 
  of 
  wood 
  about 
  20 
  cm 
  thick 
  were 
  

   interposed 
  on 
  the 
  line 
  joining 
  the 
  foci 
  of 
  the 
  mirrors, 
  clear 
  evi- 
  

   dence 
  of 
  the 
  doubly 
  refracting 
  properties 
  of 
  the 
  wood 
  could 
  be 
  

   shown 
  by 
  the 
  appearance 
  or 
  disappearance 
  of 
  the 
  spark 
  in 
  the 
  

   micrometer 
  connected 
  with 
  the 
  receiving 
  mirror. 
  — 
  Ann. 
  cler 
  

   Physik. 
  unci 
  Chemie, 
  No. 
  2, 
  1895, 
  pp. 
  342-351. 
  J. 
  t. 
  

  

  10. 
  National 
  Academy 
  of 
  Sciences 
  on 
  Electrical 
  Measurement. 
  

   — 
  The 
  standard 
  specifications 
  for 
  the 
  practical 
  application 
  of 
  the 
  

   definitions 
  of 
  the 
  electrical 
  units, 
  ampere 
  and 
  volt, 
  referred 
  to 
  

   in 
  the 
  act 
  of 
  Congress 
  of 
  July 
  12, 
  1894, 
  quoted 
  in 
  the 
  last 
  

   number 
  of 
  this 
  Journal 
  (p. 
  236), 
  are 
  given 
  below; 
  they 
  are 
  taken 
  

   from 
  Miscellaneous 
  Document, 
  No. 
  115, 
  of 
  the 
  Senate 
  of 
  the 
  

   United 
  States. 
  These 
  specifications 
  were 
  approved 
  by 
  all 
  the 
  

   members 
  of 
  the 
  committee 
  named, 
  of 
  which 
  Prof. 
  H. 
  A. 
  Rowland 
  

   was 
  the 
  chairman, 
  and 
  were 
  unanimously 
  adopted 
  by 
  the 
  Academy 
  

   at 
  a 
  special 
  meeting 
  held 
  in 
  New 
  York 
  on 
  the 
  9th 
  of 
  Febru- 
  

   ary, 
  1895. 
  

  

  Specifications 
  for 
  the 
  practical 
  application 
  of 
  the 
  definitions 
  

   of 
  the 
  Ampere 
  and 
  Volt. 
  

  

  Specification 
  A. 
  — 
  The 
  Ampere. 
  

   In 
  employing 
  the 
  silver 
  voltameter 
  to 
  measure 
  currents 
  of 
  

   about 
  one 
  ampere, 
  the 
  following 
  arrangements 
  shall 
  be 
  adopted 
  : 
  

  

  