﻿Geology 
  and 
  Mineralogy. 
  75 
  

  

  in 
  part 
  to 
  circumstances 
  of 
  impression, 
  of 
  one 
  species. 
  We 
  

   apprehend, 
  however, 
  that 
  the 
  last 
  mentioned 
  and 
  later 
  name, 
  

   adopted 
  by 
  M. 
  Zeiller 
  on 
  account 
  of 
  its 
  priority 
  in 
  respect 
  to 
  

   correct 
  diagnosis 
  and 
  illustration, 
  will 
  eventually 
  yield 
  to 
  the 
  one 
  

   proposed 
  by 
  Gutbier, 
  Tceniopteris 
  abnormis, 
  though 
  the 
  latter 
  

   was 
  quite 
  imperfectly 
  described 
  and 
  figured. 
  

  

  Zamites 
  Planchardi, 
  found 
  at 
  Teufelsbrunnen, 
  is 
  compared 
  

   with 
  the 
  live 
  other 
  species 
  of 
  Zamites 
  distinguished 
  by 
  Renault 
  

   in 
  the 
  Commentry 
  basin, 
  with 
  the 
  result 
  that 
  M. 
  Zeiller 
  is 
  led 
  to 
  

   place 
  all 
  of 
  them 
  in 
  the 
  new 
  genus 
  JPlagiozamites, 
  which 
  is 
  char- 
  

   acterized 
  by 
  its 
  lanceolate, 
  dentate 
  leaves 
  fixed 
  by 
  thickened, 
  

   clasping 
  or 
  semi-clasping 
  bases 
  oblique 
  to 
  the 
  plane 
  of 
  the 
  rachis. 
  

   Though 
  unquestionably 
  a 
  Cycad, 
  it 
  has 
  so 
  much 
  in 
  common 
  with 
  

   Noeggerathia 
  as 
  to 
  bring 
  the 
  author 
  to 
  regard 
  the 
  latter 
  as 
  be- 
  

   longing, 
  not 
  to 
  the 
  ferns, 
  but 
  to 
  the 
  Cycadece, 
  the 
  view 
  enter- 
  

   tained 
  by 
  Brongniart 
  in 
  1849. 
  In 
  considering 
  Gomphostrobus 
  

   bifidus, 
  a 
  scale 
  bifurcated 
  at 
  the 
  top, 
  to 
  be 
  a 
  seminiferous 
  scale 
  of 
  

   some 
  conifer, 
  Zeiller 
  differs 
  from 
  Potonie, 
  who 
  regards 
  it 
  as 
  a 
  

   sporangiferous 
  Psilotaceous 
  leaf. 
  d. 
  w. 
  

  

  4. 
  Artificial 
  Production 
  of 
  the 
  Mineral 
  j\ 
  T 
  orthupite. 
  — 
  An 
  arti- 
  

   ficial 
  chlorocarbonate 
  of 
  sodium 
  and 
  magnesium 
  was 
  described 
  in 
  

   1893 
  by 
  Winkler,* 
  who 
  observed 
  it 
  as 
  an 
  incrustation 
  on 
  the 
  

   inside 
  of 
  iron 
  cooling 
  tubes 
  used 
  in 
  working 
  up 
  saline 
  solutions, 
  

   rich 
  in 
  magnesium 
  chloride, 
  by 
  the 
  Solvay 
  process. 
  The 
  same 
  

   salt 
  has 
  recentlyf 
  been 
  prepared 
  and 
  described 
  by 
  de 
  Schulten, 
  

   who 
  made 
  it 
  by 
  adding 
  to 
  a 
  solution 
  of 
  20 
  grams 
  anhydrous 
  

   sodium 
  carbonate 
  and 
  150 
  grams 
  sodium 
  chloride 
  in 
  a 
  round 
  

   bottom 
  flask, 
  a 
  solution 
  of 
  15 
  grams 
  of 
  magnesium 
  chloride. 
  The 
  

   flask 
  was 
  then 
  heated 
  on 
  the 
  water 
  bath 
  for 
  seven 
  to 
  eight 
  hours. 
  

   The 
  amorphous 
  flocculent 
  precipitate 
  which 
  the 
  solution 
  of 
  magne- 
  

   sium 
  chloride 
  at 
  first 
  produced 
  gradually 
  contracted 
  and 
  trans- 
  

   formed 
  itself 
  into 
  brilliant 
  crystals 
  of 
  the 
  chlorocarbonate 
  of 
  

   sodium 
  and 
  magnesium. 
  The 
  salt 
  has 
  the 
  same 
  chemical 
  com- 
  

   position 
  as 
  the 
  mineral 
  northupite, 
  recently 
  described 
  in 
  this 
  

   Journal, 
  J; 
  as 
  will 
  be 
  seen 
  from 
  a 
  comparison 
  of 
  the 
  following 
  

   analyses: 
  

  

  

  Salt 
  (Winkler). 
  Salt 
  

  

  (de 
  Schulten). 
  

  

  Theory 
  for, 
  MgCO, 
  

   Mineral 
  (Pratt). 
  Na 
  a 
  C0 
  3 
  NaCl. 
  

  

  Na 
  2 
  

  

  24-19 
  

  

  25-21 
  

  

  24-90 
  24-96 
  

  

  MgO 
  

  

  15-07 
  

  

  15-74 
  

  

  16-22 
  16-09 
  

  

  CO, 
  

  

  33-73 
  

  

  35-87 
  

  

  35-43 
  35-41 
  

  

  NaCl 
  

  

  22-59 
  

  

  23-64 
  

  

  23-45 
  23-54 
  

  

  

  2-14 
  (NH 
  4 
  ) 
  2 
  C0 
  3 
  

   1-.92 
  CaC0 
  3 
  

  

  

  

  •04 
  FeS 
  

  

  

  

  The 
  physical 
  properties 
  of 
  the 
  salt 
  are 
  identical 
  with 
  those 
  of 
  

   the 
  mineral. 
  

  

  De 
  Schulten 
  calls 
  attention 
  to 
  the 
  similarity 
  of 
  the 
  salt 
  and 
  the 
  

  

  * 
  Zs. 
  fur 
  angewandte 
  Chemie, 
  p. 
  445, 
  1893. 
  

  

  f 
  Bull. 
  Soc. 
  Franc. 
  Min., 
  vol. 
  xix, 
  Nos. 
  5-6, 
  p. 
  164, 
  1896. 
  

  

  