﻿422 
  Scientific 
  Intelligence. 
  

  

  SCIENTIFIC 
  INTELLIGENCE. 
  

  

  I. 
  Chemistry 
  and 
  Physics. 
  

  

  1. 
  On 
  the 
  so-called 
  "Black 
  Sulphur" 
  of 
  Magnus. 
  — 
  Knapp 
  

   has 
  examined 
  the 
  mode 
  of 
  formation 
  and 
  the 
  properties 
  of 
  the 
  

   so-called 
  " 
  black 
  sulphur 
  " 
  first 
  described 
  by 
  Magnus. 
  He 
  finds 
  

   that 
  the 
  best 
  mode 
  of 
  preparing 
  it 
  is 
  to 
  heat 
  suddenly 
  a 
  mixture 
  

   of 
  sulphur 
  and 
  oil 
  ; 
  such 
  for 
  example 
  as 
  is 
  obtained 
  by 
  dissolving 
  

   almond 
  oil 
  (0*2 
  to 
  4 
  gram.) 
  in 
  ether, 
  mixing 
  the 
  solution 
  thor- 
  

   oughly 
  with 
  50 
  grams 
  flowers 
  of 
  sulphur 
  and 
  then 
  evaporating 
  

   the 
  ether. 
  If 
  a 
  small 
  portion 
  of 
  this 
  mixture 
  be 
  dropped 
  from 
  

   the 
  point 
  of 
  a 
  knife 
  on 
  to 
  the 
  bottom 
  of 
  a 
  red 
  hot 
  platinum 
  cruci- 
  

   ble, 
  most 
  of 
  it 
  is 
  volatilized, 
  but 
  there 
  is 
  left 
  a 
  loose 
  black 
  residue, 
  

   which 
  after 
  cooling 
  is 
  removed. 
  By 
  repeating 
  the 
  operation, 
  the 
  

   product 
  may 
  be 
  increased 
  indefinitely. 
  Even 
  with 
  the 
  greatest 
  

   precautions, 
  the 
  yield 
  is 
  very 
  small, 
  only 
  0*685 
  gram 
  having 
  been 
  

   obtained 
  in 
  this 
  way 
  from 
  100 
  grams 
  of 
  sulphur 
  and 
  0-4 
  gram 
  of 
  

   oil, 
  as 
  a 
  mean 
  of 
  23 
  experiments. 
  The 
  oil 
  treated 
  alone 
  in 
  this 
  

   way 
  gave 
  only 
  0*011 
  gram 
  of 
  residue. 
  As 
  thus 
  obtained 
  the 
  

   "black 
  sulphur" 
  contains 
  some 
  yellow 
  sulphur, 
  and 
  if 
  the 
  mate- 
  

   rials 
  were 
  not 
  pure, 
  also 
  some 
  ash. 
  Its 
  density 
  varies 
  from 
  2*622 
  

   to 
  1*843, 
  this 
  want 
  of 
  homogeneity 
  being 
  due 
  to 
  the 
  difficulty 
  of 
  

   regulating 
  the 
  temperature. 
  It 
  is 
  insoluble 
  in 
  hot 
  and 
  cold 
  water, 
  

   alcohol, 
  ether, 
  hydrochloric 
  acid, 
  nitric 
  acid, 
  aqua 
  regia, 
  ammonia, 
  

   caustic 
  alkalies 
  even 
  when 
  concentrated, 
  and 
  potassium 
  cyanide. 
  

   On 
  evaporating 
  it 
  with 
  potassium 
  hydroxide 
  solution, 
  it 
  is 
  at- 
  

   tacked 
  just 
  as 
  the 
  hydroxide 
  is 
  becoming 
  solid 
  and 
  dissolved 
  to 
  a 
  

   humus-brown 
  mass 
  soluble 
  in 
  water 
  with 
  a 
  deep 
  brown 
  color, 
  

   yielding 
  a 
  solution 
  in 
  which 
  acids 
  give 
  a 
  brown 
  precipitate. 
  On 
  

   heating 
  the 
  black 
  sulphur 
  in 
  the 
  air 
  it 
  undergoes 
  no 
  change 
  other 
  

   than 
  the 
  loss 
  of 
  moisture 
  and 
  yellow 
  sulphur 
  until 
  the 
  tempera- 
  

   ture 
  reaches 
  200°-300°, 
  when 
  sulphurous 
  oxide 
  is 
  formed. 
  At 
  a 
  

   red 
  heat 
  the 
  mass 
  takes 
  fire. 
  In 
  the 
  absence 
  of 
  air, 
  the 
  black 
  

   sulphur 
  slowly 
  loses 
  weight 
  and 
  continues 
  to 
  do 
  so 
  for 
  many 
  

   hours 
  even 
  at 
  a 
  red 
  heat, 
  no 
  vapor 
  of 
  sulphur 
  or 
  empyreumatic 
  

   vapors 
  being 
  evolved. 
  After 
  the 
  weight 
  becomes 
  constant, 
  the 
  

   residue 
  burns 
  away 
  in 
  the 
  air 
  entirely. 
  The 
  amount 
  of 
  this 
  resi- 
  

   due 
  was 
  43*59 
  per 
  cent. 
  Its 
  quantity 
  did 
  not 
  seem 
  to 
  vary 
  when 
  

   the 
  heating 
  took 
  place 
  in 
  carbon 
  dioxide 
  and 
  no 
  brown 
  sulphur 
  

   vapors 
  appeared 
  in 
  the 
  vessel, 
  although 
  considerable 
  potassium 
  

   sulphide 
  was 
  formed 
  when 
  the 
  delivery 
  tube 
  from 
  this 
  vessel 
  was 
  

   conducted 
  under 
  potassium 
  hydroxide 
  solution. 
  The 
  sulphur 
  in 
  the 
  

   " 
  black 
  sulphur 
  " 
  was 
  estimated 
  by 
  evaporating 
  a 
  known 
  portion 
  

   with 
  potassium 
  hydroxide 
  and 
  potassium 
  nitrate 
  solutions 
  and 
  heat- 
  

   ing, 
  until 
  the 
  residue 
  was 
  white. 
  Three 
  determinations 
  gave 
  53*77, 
  

   56*76 
  and 
  57*07 
  per 
  cent 
  of 
  sulphur, 
  respectively. 
  The 
  residue 
  left 
  

   at 
  a 
  red 
  heat 
  contained 
  22*78 
  per 
  cent 
  of 
  sulphur. 
  Thus 
  44-46 
  per 
  

  

  