﻿166 
  Scientific 
  Intelligence. 
  

  

  vanced 
  by 
  Baeyer. 
  He 
  mentions 
  a 
  possibility 
  also 
  that 
  the 
  car- 
  

   bon 
  monoxide 
  may 
  be 
  an 
  accumulated 
  waste 
  product, 
  or 
  that 
  it 
  

   may 
  be 
  formed 
  by 
  processes 
  of 
  decay. 
  He 
  does 
  not 
  mention, 
  

   however, 
  an 
  explanation 
  that 
  appears 
  to 
  be 
  more 
  plausible 
  and 
  

   interesting 
  than 
  the 
  others, 
  namely, 
  that 
  the 
  carbon 
  monoxide 
  is 
  

   produced 
  by 
  the 
  plant 
  as 
  a 
  poison 
  to 
  protect 
  itself 
  from 
  such 
  

   animals 
  as 
  might 
  bore 
  into 
  it, 
  make 
  a 
  habitation 
  in 
  its 
  cavity 
  or 
  

   feed 
  upon 
  its 
  substance. 
  Since 
  carbon 
  monoxide 
  is 
  the 
  simplest 
  

   of 
  organic 
  poisons, 
  it 
  is 
  perhaps 
  reasonable 
  to 
  suppose 
  that 
  it 
  

   might 
  be 
  utilized 
  in 
  this 
  way 
  by 
  a 
  simple 
  organism 
  like 
  kelp, 
  

   while 
  higher 
  plants 
  produce 
  alkaloids 
  and 
  other 
  more 
  complex 
  

   poisons. 
  It 
  will 
  be 
  interesting 
  to 
  examine 
  other 
  plants 
  of 
  low 
  

   orders 
  for 
  the 
  presence 
  of 
  carbon 
  monoxide. 
  It 
  appears 
  that 
  sea- 
  

   weeds 
  are 
  generally 
  very 
  free 
  from 
  the 
  attacks 
  of 
  marine 
  animals, 
  

   and 
  it 
  seems 
  possible 
  that 
  we 
  now 
  have 
  an 
  explanation 
  of 
  this 
  

   immunity. 
  The 
  further 
  suggestion 
  may 
  be 
  made 
  that 
  possibly 
  

   the 
  curiously 
  large 
  amount 
  of 
  potassium 
  chloride 
  in 
  this 
  kelp 
  

   and 
  also 
  the 
  iodine 
  that 
  occurs 
  generally 
  in 
  these 
  plants 
  may 
  be 
  

   protective 
  poisons. 
  — 
  Jour. 
  Amer. 
  Chem. 
  Soc, 
  xxxix, 
  149. 
  

  

  H. 
  L. 
  W. 
  

  

  2. 
  The 
  Atomic 
  Weight 
  of 
  Lead 
  of 
  Radioactive 
  Origin. 
  — 
  The 
  

   results 
  of 
  recent 
  work 
  by 
  several 
  independent 
  investigators 
  have 
  

   shown 
  with 
  very 
  little 
  room 
  for 
  doubt 
  that 
  the 
  metal 
  derived 
  from 
  

   this 
  source 
  has 
  a 
  much 
  lower 
  atomic 
  weight 
  than 
  ordinary 
  lead. 
  

   This 
  conclusion 
  is 
  of 
  such 
  theoretical 
  importance 
  that 
  Theodore 
  

   W. 
  Richards 
  and 
  Charles 
  Wadsworth, 
  3d, 
  have 
  extended 
  the 
  

   investigations 
  previously 
  made 
  by 
  Richards 
  and 
  Lembert 
  upon 
  

   the 
  same 
  subject. 
  Their 
  results 
  entirely 
  support 
  the 
  earlier 
  con- 
  

   clusion. 
  Atomic 
  weight 
  determinations 
  were 
  made 
  with 
  ordinary 
  

   lead 
  and 
  four 
  samples 
  of 
  radioactive 
  lead 
  with 
  the 
  following 
  

   results: 
  

  

  Ore. 
  

  

  Origin. 
  

  

  Atomic 
  wt 
  

  

  Galena 
  (?) 
  

  

  American 
  ordinary 
  lead 
  

  

  20M8 
  

  

  Carnotite 
  

  

  Colorado, 
  U. 
  S. 
  A. 
  (?) 
  

  

  207-00 
  

  

  Carnotite 
  

  

  Radium 
  Hill, 
  N. 
  S. 
  W. 
  

  

  206-34 
  

  

  Broggerite 
  

  

  Moss, 
  Norway 
  

  

  206-12 
  

  

  Cleveite 
  

  

  Langesund, 
  Norway 
  

  

  206*08 
  

  

  The 
  last 
  sample 
  is 
  the 
  most 
  carefully 
  selected 
  one, 
  and 
  is 
  prob- 
  

   ably 
  most 
  nearly 
  free 
  from 
  ordinary 
  lead. 
  While 
  it 
  is 
  possible 
  

   that 
  there 
  may 
  be 
  two 
  kinds 
  of 
  radioactive 
  lead 
  with 
  different 
  

   atomic 
  weights, 
  it 
  seems 
  more 
  probable 
  that 
  the 
  higher 
  results 
  

   from 
  the 
  carnotite 
  ores 
  are 
  due 
  entirely 
  to 
  the 
  accidental 
  admixture 
  

   of 
  ordinary 
  lead. 
  Careful 
  spectroscopic 
  examination 
  showed 
  no 
  

   lines 
  peculiar 
  to 
  the 
  radioactive 
  material. 
  It 
  was 
  found 
  that 
  the 
  

   magnitude 
  of 
  the 
  radioactivity 
  of 
  the 
  samples 
  of 
  lead 
  seemed 
  to 
  

   bear 
  no 
  relation 
  to 
  the 
  lowering 
  of 
  the 
  atomic 
  weight. 
  — 
  Jour. 
  

   Amer. 
  Chem. 
  iSoc, 
  xxviii, 
  -'613. 
  h. 
  l. 
  w. 
  

  

  3. 
  Engineering 
  Chemistry 
  ; 
  by 
  Thomas 
  B. 
  Stillman. 
  8vo, 
  

   pp. 
  743. 
  Easton, 
  Pa., 
  1916 
  (The 
  Chemical 
  Publishing 
  Co.). 
  — 
  The 
  

  

  