﻿Geology 
  and 
  Mineralogy. 
  161 
  

  

  G. 
  P. 
  Merrill 
  — 
  On 
  the 
  decomposition 
  of 
  the 
  granite 
  rocks 
  of 
  the 
  District 
  of 
  

   Columbia. 
  

  

  B. 
  Willis 
  — 
  Ancient 
  physiography 
  as 
  represented 
  by 
  sediments. 
  

  

  B. 
  K. 
  Emerson 
  — 
  Serpentine 
  psendormorphs 
  after 
  olivine, 
  formerly 
  called 
  quartz- 
  

   psendomorphs, 
  Middlefield, 
  Mass. 
  Skeleton 
  crystals 
  of 
  salt 
  which 
  have 
  been 
  

   called 
  chiastolite 
  and 
  later 
  spinel, 
  from 
  the 
  Trias, 
  Westfield, 
  Mass. 
  Radiating 
  

   puckering 
  of 
  corundum 
  crystals 
  around 
  allanite, 
  Pelham, 
  Mass. 
  

  

  C. 
  H. 
  Smyth. 
  Jr. 
  — 
  The 
  crystalline 
  limestones 
  and 
  associated 
  rocks 
  of 
  the 
  

   Northwest 
  Adirondack 
  region. 
  h. 
  s. 
  w. 
  

  

  3. 
  Manual 
  of 
  Geology. 
  Seating 
  of 
  the 
  Principles 
  of 
  the 
  

   science 
  10 
  it 
  h 
  special 
  reference 
  to 
  American 
  Geological 
  History; 
  

   by 
  James 
  D. 
  Dana. 
  4th 
  edit., 
  pp. 
  1088, 
  with 
  1575 
  figures 
  and 
  

   two 
  double-page 
  maps. 
  New 
  York, 
  1895. 
  (American 
  Book 
  

   Company). 
  — 
  Dana's 
  Manual, 
  in 
  this 
  new 
  edition, 
  is 
  a 
  wholly 
  

   rewritten 
  work, 
  a 
  total 
  revision 
  having 
  become 
  necessary 
  in 
  con- 
  

   sequence 
  of 
  the 
  great 
  progress 
  in 
  the 
  science 
  during 
  the 
  last 
  

   twenty 
  years, 
  and 
  especially 
  in 
  the 
  geology 
  of 
  the 
  Continent 
  of 
  

   North 
  America. 
  In 
  the 
  Preface 
  the 
  author 
  remarks 
  that 
  North 
  

   American 
  Geology 
  is 
  still 
  its 
  chief 
  subject 
  ; 
  and 
  adds 
  : 
  

  

  " 
  The 
  time-divisions 
  in 
  this 
  history, 
  based 
  on 
  the 
  ascertained 
  

   subdivisions 
  of 
  the 
  formations, 
  were 
  first 
  brought 
  out 
  in 
  my 
  

   Address 
  before 
  the 
  meeting 
  of 
  the 
  American 
  Association 
  at 
  

   Providence, 
  in 
  1855;* 
  and 
  in 
  1863, 
  the 
  'continuous 
  history' 
  

   appeared 
  in 
  the 
  first 
  edition 
  of 
  this 
  Manual, 
  written 
  up 
  from 
  the 
  

   State 
  Reports 
  and 
  other 
  geological 
  publications. 
  The 
  idea, 
  long 
  

   before 
  recognized, 
  that 
  all 
  observations 
  on 
  the 
  rocks, 
  however 
  

   local, 
  bore 
  directly 
  on 
  the 
  stages 
  in 
  the 
  growth 
  of 
  the 
  Continent 
  

   derives 
  universal 
  importance 
  from 
  the 
  recognition 
  of 
  North 
  

   America 
  as 
  the 
  world's 
  type 
  continent 
  — 
  the 
  only 
  continent 
  that 
  

   gives, 
  in 
  a 
  full 
  and 
  simple 
  way, 
  the 
  fundamental 
  principles 
  of 
  con- 
  

   tinental 
  development." 
  

  

  The 
  general 
  arrangement 
  of 
  the 
  work 
  remains 
  the 
  same 
  as 
  in 
  

   the 
  earlier 
  editions, 
  except 
  that 
  Dynamical 
  Geology 
  is 
  made 
  to 
  

   precede 
  Historical. 
  Moreover 
  the 
  Dynamical 
  part 
  commences 
  

   with 
  a 
  chapter 
  on 
  "Chemical 
  Work"; 
  and 
  the 
  subject 
  of 
  Moun- 
  

   tain-making 
  and 
  Earth-shaping, 
  with 
  which 
  it 
  closes, 
  is 
  treated 
  

   under 
  the 
  general 
  heading 
  of 
  " 
  Hypogeic 
  Work," 
  the 
  results, 
  

   whatever 
  the 
  agency 
  concerned, 
  whether 
  external 
  or 
  internal, 
  

   being 
  consequent 
  on 
  subterranean 
  movements. 
  

  

  In 
  the 
  preparation 
  of 
  the 
  Historical 
  part 
  of 
  the 
  Manual, 
  the 
  

   author, 
  besides 
  availing 
  himself 
  of 
  all 
  recent 
  geological 
  reports 
  

   and 
  other 
  related 
  publications, 
  carried 
  on 
  an 
  extensive 
  corre- 
  

   spondence 
  with 
  the 
  chief 
  geologists 
  of 
  the 
  country; 
  and 
  further, 
  

   in 
  the 
  paleontological 
  parts, 
  each 
  of 
  the 
  chief 
  divisions 
  of 
  the 
  

   subject 
  was 
  prepared 
  with 
  the 
  assistance 
  of 
  specialists 
  familiar 
  

   with 
  the 
  latest 
  results 
  of 
  investigation. 
  

  

  The 
  following 
  are 
  the 
  principal 
  changes 
  in 
  connection 
  with 
  the 
  

   subdivisions 
  of 
  geological 
  time. 
  

  

  Paleozoic 
  time 
  is 
  divided 
  at 
  the 
  close 
  of 
  the 
  Lower 
  Silurian, 
  

   into 
  two 
  sections 
  : 
  

  

  * 
  

  

  Republished, 
  with 
  added 
  notes, 
  in 
  this 
  Journal, 
  II, 
  xxii, 
  305, 
  1856. 
  

  

  Am. 
  Jour. 
  Sci.— 
  Third 
  Series, 
  Vol. 
  XLIX, 
  No. 
  290.— 
  Feb., 
  1895. 
  

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