﻿126 
  

  

  A 
  novelty 
  in 
  the 
  occurrence 
  of 
  calcareous 
  spar, 
  is 
  the 
  recent 
  discovery 
  

   of 
  groups 
  of 
  crystals 
  in 
  the 
  form 
  of 
  flat, 
  six-sided 
  tables, 
  of 
  various 
  

   sizes, 
  from 
  half 
  an 
  inch 
  to 
  two 
  inches 
  in 
  diameter. 
  These 
  crystals 
  

   have 
  been 
  found 
  in 
  the 
  coarse 
  granite 
  near 
  St. 
  Anthony's 
  Nose, 
  o^the 
  

   Hudson 
  river, 
  during 
  the 
  excavations 
  for 
  the 
  railroad 
  on 
  the 
  banR 
  of 
  

   that 
  stream. 
  The 
  accompanying 
  cuts 
  are 
  drawn 
  from 
  a 
  specimen 
  pre- 
  

   sented 
  to 
  the 
  State 
  Cabinet 
  by 
  John 
  E. 
  Henry, 
  which 
  is 
  one 
  of 
  the 
  best 
  

   that 
  I 
  have 
  seen 
  from 
  that 
  locality. 
  It 
  is 
  more 
  than 
  a 
  foot 
  in 
  length 
  and 
  

   breadth. 
  I 
  have 
  received 
  several 
  fine 
  specimens 
  from 
  Mr. 
  Cyrus 
  Foun- 
  

   tain, 
  of 
  Peekskill, 
  who 
  has 
  been 
  for 
  several 
  years 
  actively 
  engaged 
  in 
  

   collecting 
  the 
  minerals 
  of 
  Westchester 
  and 
  Putnam 
  counties 
  ; 
  and 
  to 
  

   whom 
  I 
  acknowledge 
  myself 
  indebted 
  for 
  many 
  interesting 
  facts, 
  which 
  

   he 
  has 
  from 
  time 
  to 
  time 
  communicated. 
  

  

  In 
  addition 
  to 
  the 
  numerous 
  forms 
  heretofore 
  figured 
  from 
  Tompkins 
  

   quarry, 
  in 
  Rockland 
  county, 
  several 
  others 
  may 
  be 
  added, 
  as 
  having 
  

   been 
  found 
  at 
  that 
  locality. 
  Among 
  these 
  are 
  the 
  dodecacdre, 
  of 
  Haiiy, 
  

   (Fig. 
  71, 
  of 
  the 
  Mineralogy 
  of 
  New-York,) 
  and 
  several 
  of 
  its 
  modifica- 
  

   tions. 
  Also 
  a 
  twin 
  of 
  the 
  same 
  form, 
  represented 
  in 
  the 
  annexed 
  figure. 
  

   In 
  other 
  crystals, 
  the 
  solid 
  angle 
  of 
  a 
  rhombohedrom 
  passes 
  through 
  the 
  

   terminal 
  planes 
  of 
  a 
  six-sided 
  prism. 
  » 
  

  

  DOLOMITE. 
  

  

  The 
  following 
  mode 
  of 
  distinguishing 
  between 
  dolomite 
  and 
  carbo- 
  

   nate 
  of 
  lime, 
  is 
  proposed 
  by 
  M. 
  Zehmen 
  : 
  Pulverize 
  a 
  small 
  quantity 
  

   of 
  the 
  mineral, 
  and 
  subject 
  it 
  to 
  the 
  heat 
  of 
  a 
  common 
  alcohol 
  lamp, 
  in 
  

   a 
  platinum 
  spoon. 
  The 
  carbonate 
  of 
  lime 
  acquires, 
  by 
  this 
  treatment, 
  

   a 
  certain 
  degree 
  of 
  coherence 
  ; 
  while 
  the 
  powder 
  of 
  dolomite, 
  which 
  

   loses 
  carbonic 
  acid, 
  remains 
  without 
  coherence. 
  Berzelius' 
  Report 
  for 
  

   1847. 
  

  

  