﻿96 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  of 
  Sturb 
  ridge, 
  Massachusetts, 
  which 
  are 
  more 
  or 
  less 
  crystalline 
  in 
  

   texture. 
  It 
  will 
  probably 
  be 
  found 
  that 
  the 
  highly 
  crystalline 
  

   lamellar 
  graphite 
  belongs, 
  in 
  all 
  cases, 
  to 
  true 
  veins, 
  where 
  a 
  

   slow 
  process 
  of 
  deposit 
  has 
  allowed 
  it 
  to 
  assume 
  that 
  mode 
  of 
  

   aggregation 
  and 
  that 
  purity 
  which 
  characterize 
  other 
  minerals 
  

   thus 
  deposited. 
  

  

  The 
  presence 
  of 
  graphite 
  in 
  veins 
  under 
  such 
  conditions 
  and 
  

   associations 
  as 
  have 
  already 
  been 
  described, 
  implies 
  its 
  separation 
  

   from 
  solution 
  at 
  an 
  elevated 
  temperature, 
  and 
  in 
  this 
  connection 
  

   the 
  curious 
  researches 
  of 
  Brodie, 
  above 
  referred 
  to, 
  have 
  shown 
  

   that 
  this 
  form 
  of 
  carbon 
  is 
  possessed 
  of 
  singular 
  chemical 
  proper- 
  

   ties 
  and 
  affinities, 
  which, 
  when 
  farther 
  studied, 
  may 
  serve 
  to 
  explain 
  

   its 
  solution 
  and 
  crystallization. 
  Meanwhile, 
  the 
  observations 
  of 
  

   Pauli 
  have 
  established 
  that 
  when 
  hydrate 
  of 
  soda, 
  mixed 
  with 
  

   cyanid 
  of 
  sodium, 
  is 
  heated 
  w 
  T 
  ith 
  nitrate 
  of 
  soda 
  to 
  incipient 
  red- 
  

   ness, 
  the 
  carbon 
  of 
  the 
  cyanid 
  separates 
  from 
  the 
  liquid 
  mass 
  in 
  

   the 
  form 
  of 
  graphite. 
  Pauli 
  moreover 
  suggests 
  that 
  native 
  graphite 
  

   may 
  have 
  been 
  separated 
  from 
  certain 
  carbon 
  compounds 
  by 
  a 
  

   process 
  analogous 
  to 
  this 
  (Phtlos. 
  Mag., 
  [4], 
  xxi, 
  541). 
  The 
  

   direct 
  transformation 
  into 
  graphite 
  of 
  carbonaceous 
  matter 
  cannot, 
  

   however, 
  be 
  doubted 
  by 
  geologists., 
  and 
  such 
  a 
  hypothesis 
  is 
  

   therefore 
  untenable 
  for 
  the 
  stratified 
  graphites. 
  This 
  reaction 
  

   described 
  by 
  Pauli 
  is 
  nevertheless 
  instructive, 
  as 
  showing 
  that 
  

   graphite 
  may 
  be 
  separated 
  from 
  solutions 
  at 
  a 
  temperature 
  not 
  

   higher 
  than 
  that 
  at 
  which, 
  according 
  to 
  Sorby, 
  the 
  minerals 
  

   which 
  accompany 
  it 
  in 
  the 
  Laurentian 
  veins 
  have 
  crystallized, 
  

   although 
  we 
  cannot, 
  in 
  the 
  formation 
  of 
  these 
  veins, 
  suppose 
  the 
  

   intervention 
  of 
  these 
  same 
  chemical 
  reagents 
  as 
  in 
  the 
  experiment 
  

   of 
  Pauli. 
  

  

  Graphite 
  may 
  undoubtedly 
  be 
  formed 
  at 
  much 
  higher 
  tempera- 
  

   tures. 
  Its 
  occurrence 
  in 
  cast-iron 
  is 
  well 
  known 
  ; 
  and 
  Brodie, 
  

   who 
  obtained, 
  by 
  dissolving 
  a 
  graphitic 
  iron 
  in 
  acid, 
  four 
  per 
  cent 
  

   of 
  lamellar 
  graphite, 
  found 
  it 
  to 
  be 
  identical 
  in 
  physical 
  characters 
  

   with 
  that 
  met 
  with 
  in 
  nature. 
  Jacquelain 
  also, 
  by 
  the 
  decomposi- 
  

   tion 
  of 
  sulphuret 
  of 
  carbon 
  in 
  contact 
  with 
  metallic 
  copper, 
  at 
  

   800° 
  Centigrade, 
  obtained, 
  together 
  with 
  sulphuret 
  of 
  copper, 
  

   amorphous 
  graphite. 
  Starting 
  from 
  this 
  experiment, 
  Jacquelain 
  

   suggests 
  that 
  native 
  graphite 
  may 
  have 
  originated 
  from 
  the 
  distil- 
  

   lation 
  into 
  the 
  fissures 
  of 
  rocks 
  of 
  volatile 
  hydro-carbons, 
  which 
  

   have 
  there, 
  by 
  a 
  decomposition 
  similar 
  to 
  that 
  which 
  takes 
  place 
  

   in 
  contact 
  with 
  the 
  walls 
  of 
  coal-gas 
  retorts, 
  given 
  rise 
  to 
  a 
  deposit 
  

  

  