﻿74 
  Scientific 
  Intelligence. 
  

  

  with 
  a 
  smoky 
  flame 
  in 
  the 
  air, 
  but 
  it 
  may 
  be 
  sublimed 
  by 
  heating 
  

   in 
  a 
  vacuum. 
  It 
  is 
  almost 
  insoluble 
  in 
  cold 
  water, 
  but 
  upon 
  

   warming 
  with 
  water 
  it 
  forms 
  mellitic 
  acid, 
  C 
  12 
  H 
  6 
  12 
  . 
  — 
  Berichte, 
  

   xlvi, 
  813. 
  h. 
  l. 
  w. 
  

  

  3. 
  The 
  Examination 
  of 
  Waters 
  and 
  Water 
  Supplies; 
  by 
  

   John 
  C. 
  Thresh. 
  Second 
  Edition. 
  8vo, 
  pp. 
  644. 
  Philadelphia, 
  

   1913 
  (P. 
  Blakiston's 
  Son 
  & 
  Co. 
  Price 
  $5.00 
  net). 
  — 
  This 
  is 
  an 
  

   admirable 
  treatise, 
  dealing 
  with 
  all 
  the 
  aspects 
  of 
  the 
  subject 
  

   under 
  conditions 
  existing 
  in 
  England. 
  The 
  author 
  emphasizes 
  

   the 
  importance 
  of 
  the 
  examination 
  of 
  sources 
  of 
  water 
  supply, 
  

   and 
  gives 
  an 
  excellent 
  discussion 
  of 
  this 
  topic. 
  The 
  methods 
  of 
  

   water 
  examination 
  are 
  very 
  fully 
  treated, 
  and 
  the 
  results 
  of 
  

   many 
  analyses, 
  useful 
  for 
  comparison, 
  are 
  given. 
  There 
  are 
  34 
  

   plates 
  illustrating 
  microscopical 
  objects 
  found 
  in 
  water. 
  It 
  may 
  

   be 
  mentioned 
  that 
  the 
  author 
  employs 
  an 
  ingenious 
  and 
  appar- 
  

   ently 
  novel 
  device 
  for 
  eliminating 
  the 
  error 
  due 
  to 
  the 
  excess 
  of 
  

   the 
  reagent 
  necessary 
  to 
  produce 
  the 
  end-reaction 
  in 
  connection 
  

   with 
  certain 
  volumetric 
  determinations. 
  For 
  example, 
  in 
  deter- 
  

   mining 
  hydrogen 
  sulphide 
  with 
  centinormal 
  iodine 
  solution 
  it 
  

   was 
  found 
  that 
  500 
  cc 
  of 
  the 
  water 
  required 
  9 
  CC 
  of 
  the 
  iodine 
  solu- 
  

   tion 
  to 
  give 
  a 
  blue 
  color 
  with 
  starch 
  ; 
  then 
  8 
  CC 
  more 
  of 
  the 
  water 
  

   itself 
  removed 
  the 
  blue 
  color. 
  It 
  was 
  assumed 
  that 
  the 
  true 
  end- 
  

   point 
  lay 
  half 
  way 
  between 
  500 
  and 
  508 
  cc 
  of 
  water, 
  so 
  that 
  504 
  cc 
  

   was 
  the 
  amount 
  used 
  for 
  the 
  calculation. 
  The 
  same 
  plan 
  is 
  used 
  

   in 
  determining 
  chlorine 
  by 
  means 
  of 
  silver 
  nitrate 
  with 
  a 
  chro- 
  

   mate 
  as 
  indicator. 
  In 
  a 
  few 
  operations 
  the 
  author 
  recommends 
  

   the 
  use 
  of 
  weighed 
  paper 
  filters 
  where 
  the 
  employment 
  of 
  the 
  

   Gooch 
  filter 
  is 
  to 
  be 
  preferred. 
  h. 
  l. 
  w. 
  

  

  4. 
  Gas 
  Analysis 
  ; 
  by 
  L. 
  M. 
  Dennis 
  ; 
  8vo, 
  pp. 
  434. 
  New 
  

   York. 
  1913 
  (The 
  Macmillan 
  Companj\ 
  Price 
  $2.10 
  net). 
  — 
  

   This 
  very 
  full 
  and 
  satisfactory 
  text-book 
  on 
  gas 
  analysis 
  will 
  be 
  

   welcomed 
  by 
  all 
  who 
  are 
  interested 
  in 
  teaching 
  or 
  practising 
  this 
  

   branch 
  of 
  analytical 
  chemistry. 
  In 
  its 
  general 
  plan 
  the 
  book 
  fol- 
  

   lows 
  the 
  author's 
  well 
  known 
  translation 
  of 
  Hempel's 
  work, 
  but 
  

   much 
  new 
  material 
  has 
  been 
  added, 
  and 
  many 
  of 
  the 
  older 
  methods 
  

   have 
  been 
  modified 
  or 
  omitted, 
  so 
  that 
  the 
  book 
  is 
  actually 
  a 
  new 
  

   and 
  priginal 
  work. 
  While 
  the 
  greater 
  part 
  of 
  the 
  book 
  is 
  devoted 
  

   to 
  rapid 
  methods 
  of 
  technical 
  gas 
  analysis, 
  descriptions 
  are 
  given 
  

   also 
  of 
  certain 
  methods 
  of 
  exact 
  analysis 
  that 
  are 
  adapted 
  to 
  

   specific 
  determinations. 
  The 
  manipulation 
  of 
  the 
  more 
  generally 
  

   used 
  types 
  of 
  apparatus 
  is 
  very 
  fully 
  described, 
  the 
  illustrations 
  

   are 
  excellent, 
  and 
  in 
  general 
  the 
  book 
  deserves 
  the 
  highest 
  praise. 
  

  

  h. 
  l. 
  w. 
  

  

  5. 
  Chemical 
  Analysis 
  for 
  Students 
  of 
  Medicine, 
  Pharmacy, 
  

   and 
  Dentistry 
  ; 
  by 
  Elbert 
  W. 
  Rockwood 
  ; 
  8vo, 
  pp. 
  247. 
  Phila- 
  

   delphia, 
  1913 
  (P. 
  Blakiston's 
  Son 
  & 
  Co.).— 
  The 
  fact 
  that 
  this 
  is 
  

   the 
  fourth 
  edition 
  shows 
  that 
  the 
  book 
  is 
  extensively 
  used. 
  

   After 
  an 
  introduction 
  dealing 
  with 
  operations 
  and 
  a 
  few 
  general 
  

   principles, 
  a 
  course 
  of 
  inorganic 
  qualitative 
  analysis 
  is 
  taken 
  up, 
  

   which 
  is 
  fairly 
  extensive. 
  Then 
  comes 
  a 
  chapter 
  on 
  the 
  qualita- 
  

  

  