﻿Brackett 
  and 
  Williams 
  — 
  Newtonite 
  and 
  Rector 
  ite. 
  13 
  

  

  termining 
  their 
  water 
  of 
  constitution 
  under 
  the 
  conditions 
  

   mentioned 
  below. 
  

  

  Since 
  kaolin 
  approaches 
  the 
  composition 
  represented 
  by 
  the 
  

   formula 
  ascribed 
  to 
  it 
  only 
  when 
  it 
  has 
  been 
  dried 
  at 
  about 
  

   110° 
  C, 
  and 
  from 
  the 
  facts 
  mentioned 
  below 
  regarding 
  halloy- 
  

   site, 
  we 
  propose 
  to 
  consider 
  the 
  whole 
  series 
  as 
  based 
  upon 
  

   analyses 
  of 
  material 
  dried 
  at 
  110° 
  C. 
  or 
  thereabouts. 
  

  

  Considering 
  the 
  series 
  in 
  this 
  way, 
  at 
  least 
  one 
  and 
  probably 
  

   two 
  hydrous 
  silicates 
  of 
  alumina 
  lately 
  analyzed 
  in 
  the 
  labora- 
  

   tory 
  of 
  the 
  Geological 
  Survey 
  of 
  Arkansas 
  fall 
  into 
  this 
  series. 
  

   One 
  of 
  these 
  corresponds 
  to 
  No. 
  4 
  and 
  the 
  other 
  possibly 
  to 
  

   No. 
  1 
  of 
  the 
  series. 
  

  

  Newtonite. 
  

  

  The 
  first 
  compound 
  which 
  will 
  be 
  described, 
  and 
  that 
  which 
  

   suggested 
  the 
  series 
  given 
  above, 
  is 
  found 
  on 
  Sneed's 
  Creek 
  in 
  

   the 
  northern 
  part 
  of 
  Newton 
  county 
  (16 
  N., 
  23 
  W., 
  section 
  1), 
  

   in 
  the 
  State 
  of 
  Arkansas. 
  At 
  this 
  place 
  a 
  mineral 
  claim 
  was 
  

   laid 
  and 
  a 
  shaft 
  opened 
  in 
  1889 
  by 
  Mr. 
  W. 
  S. 
  Allen 
  of 
  Har- 
  

   rison, 
  Ark. 
  The 
  rocks 
  of 
  the 
  region 
  are 
  for 
  the 
  most 
  part 
  

   sandstones 
  and 
  shales 
  of 
  the 
  Barren 
  Coal 
  Measures, 
  while 
  the 
  

   opening 
  itself 
  seems 
  to 
  penetrate 
  some 
  of 
  the 
  limestones 
  of 
  the 
  

   Lower 
  Carboniferous 
  series. 
  At 
  a 
  depth 
  of 
  eight 
  feet 
  this 
  

   form 
  of 
  kaolin 
  was 
  found 
  imbedded 
  in 
  a 
  dark 
  gray 
  clay, 
  

   through 
  which 
  it 
  is 
  scattered 
  in 
  lumps 
  which 
  vary 
  from 
  a 
  few 
  

   ounces 
  to 
  forty 
  pounds 
  in 
  weight. 
  Iron 
  and 
  a 
  little 
  manganese 
  

   are 
  also 
  said 
  to 
  occur 
  in 
  the 
  opening. 
  Samples 
  of 
  the 
  material 
  

   were 
  kindly 
  furnished 
  the 
  Geological 
  Survey 
  of 
  Arkansas 
  by 
  

   Mr. 
  Allen, 
  the 
  proprietor 
  of 
  the 
  claim. 
  

  

  On 
  account 
  of 
  its 
  occurrence 
  in 
  Newton 
  county 
  we 
  propose 
  

   the 
  name 
  Neivtonite 
  for 
  this, 
  the 
  fourth 
  member 
  of 
  the 
  

   Kaolinite 
  Series. 
  

  

  Newtonite 
  is 
  a. 
  pure 
  white, 
  soft, 
  compact, 
  homogeneous 
  sub- 
  

   stance, 
  and 
  both 
  chemical 
  analysis 
  and 
  microscopic 
  examination 
  

   show 
  it 
  to 
  be 
  a 
  remarkably 
  pure 
  substance. 
  It 
  is 
  infusible 
  

   before 
  the 
  blowpipe, 
  and 
  when 
  in 
  the 
  form 
  of 
  a 
  powder 
  it 
  has 
  

   a 
  specific 
  gravity 
  of 
  2*37. 
  It 
  is 
  only 
  slightly 
  attacked 
  by 
  boil- 
  

   ing 
  concentrated 
  hydrochloric 
  acid, 
  but 
  boiling 
  concentrated 
  

   sulphuric 
  acid 
  decomposes 
  it 
  almost 
  completely, 
  with 
  a 
  separa- 
  

   tion 
  of 
  silica. 
  It 
  is 
  also 
  decomposed 
  by 
  a 
  boiling 
  saturated 
  

   solution 
  of 
  caustic 
  potash 
  with 
  the 
  formation 
  of 
  a 
  compound 
  

   insoluble 
  in 
  water 
  but 
  easily 
  soluble 
  in 
  cold 
  dilute 
  hydrochloric 
  

   acid. 
  (See 
  below.) 
  

  

  Quantitative 
  chemical 
  analyses 
  of 
  newtonite 
  gave 
  the 
  follow- 
  

   ing 
  results 
  : 
  

  

  