﻿426 
  Scientific 
  Intelligence. 
  

  

  subject. 
  A 
  brief 
  review 
  of 
  the 
  author's 
  facts 
  and 
  conclusions 
  

   have 
  been 
  given 
  in 
  volume 
  xlv 
  (p. 
  358) 
  of 
  this 
  Journal, 
  in 
  a 
  

   letter 
  from 
  the 
  author. 
  The 
  many 
  plates 
  contain 
  various 
  contour 
  

   maps, 
  and 
  views 
  of 
  reef 
  regions, 
  of 
  reolian 
  bluffs 
  and 
  rock, 
  and 
  

   illustrations 
  of 
  other 
  subjects. 
  Plate 
  VIII 
  is 
  a 
  colored 
  contour 
  

   map 
  of 
  the 
  Caribbean 
  Sea. 
  

  

  Prof. 
  Agassiz, 
  in 
  discussing 
  the 
  origin 
  of 
  coral 
  reef 
  limestones, 
  

   states 
  objections 
  to 
  the 
  subsidence 
  theory 
  of 
  Darwin. 
  Without 
  

   touching 
  here 
  on 
  the 
  special 
  arguments 
  in 
  its 
  favor, 
  two 
  or 
  

   three 
  general 
  facts 
  may 
  be 
  stated. 
  

  

  In 
  geological 
  history, 
  many 
  limestones 
  have 
  been 
  made 
  exceed- 
  

   ing 
  1000 
  feet 
  in 
  thickness 
  which 
  show 
  by 
  their 
  fossils 
  that 
  they 
  

   are 
  not 
  of 
  deep 
  water 
  origin. 
  Whether 
  derived 
  from 
  coral 
  and 
  

   shell 
  sediment 
  like 
  coral 
  reef 
  rock, 
  or 
  from 
  shell 
  sediment 
  chiefly 
  

   makes 
  no 
  difference 
  ; 
  subsidence 
  was 
  required. 
  

  

  Subsidences 
  of 
  one 
  or 
  two 
  scores 
  of 
  thousands 
  of 
  feet 
  in 
  depth 
  

   have 
  taken 
  place 
  in 
  past 
  time, 
  over 
  the 
  region 
  of 
  the 
  Appala- 
  

   chians, 
  Alps, 
  and 
  other 
  mountain 
  regions; 
  and 
  in 
  the 
  sinking 
  

   trough, 
  sediments 
  were 
  formed 
  successively 
  at 
  the 
  water's 
  level, 
  

   or 
  not 
  far 
  below 
  it, 
  to 
  the 
  thickness 
  of 
  the 
  depth 
  of 
  subsidence 
  ; 
  

   and 
  some 
  of 
  the 
  sediments 
  were 
  calcareous, 
  making 
  now 
  thick 
  

   limestone 
  strata. 
  

  

  After 
  the 
  Cretaceous 
  period, 
  and 
  in 
  the 
  Pliocene 
  Tertiary 
  

   chiefly, 
  or 
  the 
  Tertiary 
  and 
  Glacial 
  period, 
  the 
  whole 
  region 
  of 
  

   the 
  Rocky 
  Mountains 
  was 
  elevated; 
  the 
  elevation 
  was 
  16,000 
  

   feet 
  in 
  part 
  of 
  Colorado, 
  10,000 
  feet 
  at 
  least 
  in 
  the 
  region 
  of 
  

   the 
  Sierra 
  Nevada, 
  10,000 
  feet 
  in 
  Mexico, 
  and 
  over 
  17,000 
  feet 
  

   in 
  British 
  America, 
  latitude, 
  49° 
  to 
  53° 
  and 
  less 
  to 
  the 
  north. 
  

   The 
  region 
  of 
  the 
  Andes, 
  at 
  the 
  same 
  time, 
  was 
  raised 
  to 
  a 
  maxi- 
  

   mum 
  amount 
  of 
  20,000 
  feet; 
  the 
  Alps, 
  12,000; 
  the 
  Himalayas, 
  

   20,000 
  feet. 
  Moreover, 
  at 
  the 
  close 
  of 
  the 
  Champlain 
  period 
  there 
  

   was 
  another 
  epoch 
  of 
  smaller 
  elevation, 
  introducing 
  the 
  Recent 
  

   period. 
  These 
  elevations, 
  affecting 
  a 
  large 
  part 
  of 
  the 
  continental 
  

   areas, 
  could 
  not 
  have 
  taken 
  place 
  without 
  a 
  counterpart 
  subsidence 
  

   of 
  large 
  areas 
  over 
  the 
  oceanic 
  basin 
  ; 
  profound 
  oceanic 
  subsi- 
  

   dence 
  was 
  hence 
  in 
  progress 
  during 
  the 
  growth 
  of 
  coral 
  reefs. 
  

   The 
  subsidence 
  cannot 
  be 
  questioned. 
  j. 
  d. 
  d. 
  

  

  2. 
  Formation 
  of 
  Dolomite. 
  — 
  C. 
  Klement, 
  has 
  a 
  paper 
  on 
  

   the 
  formation 
  of 
  dolomite 
  in 
  the 
  "Bulletin 
  de 
  la 
  Societe 
  

   Beige 
  de 
  Geologie, 
  Paleontologie 
  et 
  Hydrologie," 
  Volume 
  viii, 
  

   Brussels. 
  1894. 
  In 
  experiments, 
  proceeding 
  on 
  the 
  ground 
  

   that 
  the 
  calcium 
  carbonate 
  of 
  corals 
  is 
  in 
  the 
  state 
  of 
  ara- 
  

   gonite, 
  he 
  digested 
  in 
  a 
  covered 
  platinum 
  capsule, 
  at 
  a 
  tem- 
  

   perature 
  of 
  90° 
  to 
  92° 
  C, 
  finely 
  pulverized 
  aragonite, 
  with 
  a 
  

   concentrated 
  solution 
  of 
  common 
  salt 
  and 
  magnesium 
  chloride 
  

   and 
  sulphate 
  in 
  the 
  proportions 
  occurring 
  in 
  sea-water. 
  

  

  In 
  his 
  several 
  trials 
  he 
  obtained 
  a 
  compound 
  containing, 
  

   besides 
  lime 
  and 
  carbonic 
  acid, 
  15 
  to 
  32*5 
  per 
  cent, 
  of 
  magnesia, 
  

   corresponding 
  to 
  31*5 
  to 
  68*3 
  per 
  cent, 
  of 
  magnesium 
  carbonate. 
  

   During 
  the 
  operation, 
  the 
  solution 
  employed 
  was 
  gradually 
  con- 
  

  

  