﻿432 
  Scientific 
  Intelligence. 
  

  

  (Ill) 
  : 
  (111) 
  98° 
  V 
  9r 
  51' 
  (calc. 
  v. 
  Kok.) 
  

  

  (Ill) 
  : 
  (001) 
  111° 
  36' 
  111° 
  42' 
  

   (111) 
  : 
  (111) 
  136° 
  20' 
  136° 
  36' 
  

  

  The 
  smaller 
  crystals 
  when 
  placed 
  under 
  the 
  microscope 
  are 
  

   found 
  to 
  be 
  translucent 
  with 
  a 
  rather 
  pale 
  yellow 
  color, 
  metallic 
  

   lustre, 
  and 
  high 
  refractive 
  index. 
  These 
  show 
  parallel 
  extinction 
  

   and 
  a 
  uniaxial 
  figure. 
  

  

  I 
  am 
  indebted 
  to 
  my 
  friend, 
  Prof. 
  W. 
  G. 
  Brown 
  of 
  Washington 
  

   and 
  Lee 
  University, 
  for 
  chemically 
  examining 
  one 
  of 
  the 
  crystals, 
  

   which 
  he 
  found 
  to 
  be 
  composed 
  largely 
  of 
  titanic 
  oxide. 
  

  

  Baltimore, 
  Aug., 
  1891. 
  

  

  5. 
  Ilvaite 
  ; 
  by 
  G. 
  Ch. 
  Hoffmann 
  (communicated). 
  — 
  Several 
  

   specimens 
  of 
  what 
  proved 
  to 
  be 
  the 
  rare 
  mineral, 
  ilvaite, 
  were 
  

   received 
  for 
  identification 
  from 
  a 
  gentleman 
  who 
  described 
  it 
  as 
  

   occurring 
  in 
  large 
  irregular 
  masses 
  in 
  a 
  vein 
  about 
  twenty 
  feet 
  

   wide, 
  near 
  the 
  head 
  of 
  Barclay 
  Sound, 
  Vancouver 
  Island, 
  British 
  

   Columbia. 
  Portions 
  of 
  the 
  material 
  were 
  fairly 
  free 
  from 
  for- 
  

   eign 
  admixture 
  containing 
  only 
  small 
  quantities 
  of 
  a 
  white 
  trans- 
  

   lucent, 
  cleavable 
  calcite, 
  this, 
  however, 
  was 
  in 
  some 
  fragments 
  

   supplemented 
  by 
  inclusions 
  of 
  altered 
  tremolite, 
  and 
  in 
  others 
  by 
  

   a 
  brownish-yellow 
  andradite. 
  It 
  had 
  a 
  more 
  or 
  less 
  closely 
  com- 
  

   pacted 
  crystalline 
  structure. 
  The 
  lateral 
  faces 
  of 
  crystals 
  were 
  

   not 
  infrequently 
  striated 
  longitudinally, 
  and 
  sometimes 
  exhibited 
  

   a 
  slight 
  iridescent 
  tarnish. 
  Color, 
  iron-black 
  ; 
  streak, 
  greenish- 
  

   black 
  ; 
  luster, 
  sub-metallic, 
  brittle 
  ; 
  fracture, 
  uneven. 
  Before 
  

   the 
  blow-pipe 
  fuses 
  quietly 
  at 
  about 
  2*5 
  to 
  a 
  black 
  magnetic 
  

   globule. 
  Hardness, 
  5*5 
  ; 
  specific 
  gravity, 
  3 
  # 
  85. 
  Readily 
  decom- 
  

   posed 
  by 
  hydrochloric 
  acid, 
  forming 
  a 
  yellow 
  jelly. 
  

  

  An 
  analysis 
  conducted 
  upon 
  very 
  carefully 
  selected 
  and 
  pre- 
  

   pared 
  material, 
  dried 
  at 
  100° 
  C, 
  afforded 
  the 
  following 
  results 
  : 
  

  

  Si0 
  2 
  A1 
  2 
  3 
  Fe 
  2 
  3 
  FeO 
  MnO 
  CaO 
  MgO 
  H 
  2 
  

  

  2981 
  0-16 
  18-89 
  32*50 
  2-22 
  13'82 
  0-30 
  1-62 
  = 
  99'32 
  

  

  6. 
  Synthese 
  dn 
  IZubis, 
  par 
  E. 
  Feemy. 
  30 
  pp. 
  4to, 
  with 
  28 
  

   colored 
  plates. 
  Paris, 
  1891, 
  (Vve. 
  Ch. 
  Dunod.) 
  — 
  The 
  synthetic 
  

   formation 
  of 
  minerals 
  in 
  general 
  is 
  a 
  subject 
  of 
  great 
  interest 
  and 
  

   one 
  in 
  which 
  French 
  chemists 
  have 
  made 
  remarkable 
  progress 
  of 
  

   late 
  years. 
  The 
  results 
  reached 
  by 
  one 
  of 
  the 
  laborers 
  in 
  this 
  

   field, 
  M. 
  Fremy, 
  in 
  the 
  artificial 
  production 
  of 
  rubies 
  are 
  given 
  

   in 
  this 
  beautiful 
  volume. 
  In 
  the 
  most 
  successful 
  method, 
  the 
  

   rubies 
  were 
  obtained 
  in 
  an 
  earthen 
  crucible 
  by 
  the 
  reaction 
  at 
  a 
  

   very 
  high 
  temperature 
  of 
  a 
  mixture 
  of 
  alumina 
  (with 
  more 
  or 
  

   less 
  potash) 
  upon 
  barium 
  fluoride, 
  with 
  bichromate 
  of 
  potash 
  as 
  

   coloring 
  matter. 
  They 
  are 
  well 
  crystallized, 
  clear, 
  of 
  brilliant 
  

   color 
  and 
  sometimes 
  weigh 
  one-third 
  of 
  a 
  carat. 
  The 
  author 
  

   claims 
  for 
  them 
  usefulness 
  both 
  in 
  jewelry 
  and 
  in 
  watchmaking. 
  

   A 
  series 
  of 
  fine 
  colored 
  plates 
  show 
  sections 
  of 
  the 
  crucibles 
  with 
  

   the 
  rubies 
  scattered 
  through 
  the 
  gangue, 
  also 
  clear 
  isolated 
  rhom- 
  

   bohedral 
  crystals 
  (magnified), 
  and 
  further, 
  the 
  rubies 
  cut 
  and 
  

   mounted 
  for 
  ornament 
  in 
  various 
  forms. 
  

  

  