﻿62 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  at 
  temperatures 
  in 
  some 
  cases 
  equal 
  to 
  that 
  of 
  low 
  redness, 
  under 
  a 
  

   pressure 
  equal 
  to 
  that 
  of 
  several 
  thousand 
  feet 
  of 
  rock, 
  and 
  in 
  the 
  

   presence 
  of 
  water 
  holding 
  in 
  solution 
  a 
  large 
  amount 
  of 
  alkaline 
  

   salts, 
  which 
  can 
  in 
  some 
  instances 
  be 
  detected 
  in 
  the 
  liquid 
  from 
  

   these 
  cavities. 
  

  

  These 
  conclusions 
  are 
  supported 
  by 
  the 
  experiments 
  of 
  Daubree, 
  

   who 
  succeeded 
  in 
  forming 
  crystallized 
  pyroxene, 
  feldspar 
  and 
  

   quartz, 
  in 
  the 
  presence 
  of 
  alkaline 
  solutions 
  at 
  a 
  low 
  red 
  heat. 
  

   De 
  Senarmont 
  also 
  obtained 
  crystallized 
  fluor-spar, 
  sulphate 
  of 
  

   barytes 
  and 
  quartz, 
  in 
  the 
  presence 
  of 
  water, 
  at 
  temperatures 
  

   between 
  200° 
  and 
  300° 
  Centigrade. 
  The 
  deposits 
  from 
  the 
  ther- 
  

   mal 
  waters 
  of 
  Plombieres, 
  however, 
  show 
  that 
  some 
  hydrous 
  

   silicates, 
  like 
  apoplryllite, 
  harmotome 
  and 
  chabazite, 
  may 
  be 
  crys- 
  

   tallized 
  at 
  temperatures 
  below 
  that 
  of 
  boiling 
  water, 
  and 
  there 
  

   are 
  reasons 
  for 
  believing 
  that 
  quartz 
  may 
  also 
  be 
  crystallized 
  at 
  

   low 
  temperatures. 
  Thus, 
  while 
  the 
  observations 
  of 
  Sorby 
  show 
  

   the 
  temperatures 
  at 
  which 
  certain 
  minerals 
  have 
  been 
  crystallized, 
  

   it 
  does 
  not 
  necessarily 
  follow 
  that 
  some 
  of 
  these 
  crystals 
  may 
  not 
  

   be 
  generated 
  at 
  lower 
  degrees 
  of 
  heat, 
  which, 
  for 
  the 
  minerals 
  

   found 
  in 
  nature, 
  must, 
  in 
  each 
  case, 
  be 
  determined 
  by 
  experiments 
  

   like 
  those 
  of 
  Mr. 
  Sorby. 
  

  

  It 
  will 
  be 
  readily 
  understood 
  that 
  the 
  conclusions 
  as 
  to 
  the 
  con- 
  

   ditions 
  of 
  temperature 
  under 
  which 
  certain 
  minerals 
  have 
  been 
  

   crystallized, 
  apply 
  with 
  equal 
  force 
  to 
  those 
  freely 
  deposited 
  in 
  

   fissures 
  or 
  cavities 
  of 
  the 
  sedimentary 
  rocks, 
  and 
  those 
  which 
  may 
  

   have 
  cyrstallized 
  in 
  the 
  midst 
  of 
  the 
  deeply 
  buried 
  sediments 
  

   themselves 
  ; 
  since 
  these 
  must 
  have 
  been 
  permeated 
  with 
  the 
  same 
  

   solutions 
  which 
  circulated 
  in 
  the 
  fissures, 
  and 
  which, 
  in 
  fact, 
  derived 
  

   from 
  the 
  beds 
  their 
  dissolved 
  mineral 
  matters. 
  The 
  solvent 
  power 
  

   of 
  waters 
  holding 
  alkaline 
  carbonates 
  and 
  silicates, 
  and 
  heated 
  to 
  

   300° 
  or 
  360° 
  Centigrade, 
  is 
  probably 
  very 
  great. 
  The 
  questions 
  

   of 
  the 
  generation 
  of 
  many 
  of 
  these 
  silicates, 
  and 
  of 
  the 
  original 
  

   composition 
  of 
  the 
  sedimentary 
  rocks, 
  will 
  be 
  discussed 
  further 
  on. 
  

  

  Those 
  who 
  have 
  written 
  on 
  crystalline 
  limestones, 
  and 
  on 
  their 
  

   mineralogy, 
  have, 
  for 
  the 
  most 
  part, 
  neglected 
  the 
  distinction 
  

   between 
  the 
  rock 
  and 
  its 
  veins 
  ; 
  thus 
  Delesse 
  in 
  his 
  elaborate 
  

   memoir 
  on 
  the 
  minerals 
  of 
  crystalline 
  limestones, 
  does 
  not 
  even 
  

   allude 
  to 
  it. 
  Incidentally, 
  however, 
  several 
  observers 
  have 
  noticed 
  

   the 
  occurrence 
  of 
  various 
  crystallized 
  minerals 
  in 
  veins 
  among 
  the 
  

   Laurentian 
  limestones 
  of 
  New 
  York 
  and 
  New 
  Jersey. 
  First 
  among 
  

   these 
  may 
  be 
  mentioned 
  Prof. 
  Charles 
  Upham 
  Shepard, 
  who, 
  in 
  

  

  