﻿428 
  Scientific 
  Intelligence. 
  

  

  Matthew 
  Carey 
  Lea 
  died 
  at 
  his 
  residence 
  on 
  Sunset 
  Avenue, 
  

   Chestnut 
  Hill, 
  Philadelphia, 
  on 
  the 
  15th 
  of 
  March, 
  1897. 
  He 
  

   was 
  born 
  in 
  1823, 
  and 
  was 
  the 
  eldest 
  son 
  of 
  Isaac 
  Lea, 
  the 
  pub- 
  

   lisher, 
  well 
  known 
  as 
  a 
  geologist 
  and 
  mineralogist, 
  but 
  especially 
  

   as 
  a 
  conchologist, 
  in 
  connection 
  with 
  his 
  investigations 
  on 
  the 
  

   genus 
  Unio. 
  Mr. 
  Lea 
  was 
  a 
  member 
  of 
  one 
  of 
  the 
  old 
  Quaker 
  

   families 
  of 
  Philadelphia, 
  his 
  ancestor 
  John 
  Lea 
  who 
  was 
  an 
  active 
  

   member 
  of 
  the 
  Society 
  of 
  Friends 
  having 
  come 
  to 
  this 
  country 
  

   with 
  William 
  Penn 
  in 
  1700. 
  Carey 
  Lea 
  was 
  educated 
  at 
  home 
  

   by 
  private 
  tutors 
  and 
  studied 
  law 
  in 
  the 
  office 
  of 
  the 
  late 
  Wm. 
  

   M. 
  Meredith, 
  being 
  subsequently 
  admitted 
  to 
  the 
  bar. 
  On 
  

   account 
  of 
  chronic 
  ill 
  health, 
  however, 
  he 
  never 
  practised 
  his 
  pro- 
  

   fession. 
  His 
  early 
  associations 
  giving 
  him 
  a 
  special 
  interest 
  in 
  

   scientific 
  matters, 
  he 
  entered 
  the 
  laboratory 
  of 
  Professor 
  James 
  C. 
  

   Booth 
  and 
  there 
  acquired 
  great 
  proficiency 
  in 
  chemistry. 
  To 
  this 
  

   science 
  he 
  devoted 
  his 
  life, 
  his 
  chemical 
  researches 
  being 
  numerous 
  

   and 
  important, 
  by 
  far 
  the 
  greater 
  number 
  having 
  been 
  published 
  

   in 
  the 
  pages 
  of 
  this 
  Journal. 
  He 
  was 
  elected 
  to 
  membership 
  in 
  

   the 
  National 
  Academy 
  of 
  Sciences 
  in 
  1892 
  and 
  the 
  list 
  of 
  his 
  

   more 
  important 
  papers 
  then 
  published 
  contained 
  fifty 
  four 
  titles. 
  

   These 
  investigations 
  for 
  the 
  most 
  part 
  related 
  to 
  the 
  chemistry 
  of 
  

   photography, 
  and 
  especially 
  to 
  the 
  action 
  of 
  light 
  and 
  other 
  forms 
  

   of 
  energy 
  upon 
  silver 
  salts. 
  He 
  described 
  photo-bromide 
  and 
  

   photo-iodide 
  of 
  silver 
  and 
  in 
  1887 
  published 
  a 
  paper 
  on 
  the 
  

   ''Identity 
  of 
  the 
  photo-salts 
  of 
  silver 
  with 
  the 
  material 
  of 
  the 
  

   latent 
  Photographic 
  Image." 
  His 
  most 
  remarkable 
  discovery 
  

   however, 
  made 
  in 
  1889, 
  was 
  that 
  silver 
  is 
  capable 
  of 
  existing 
  in 
  

   three 
  allotropic 
  states. 
  The 
  first 
  is 
  allotropic 
  silver 
  proper, 
  

   "which 
  is 
  protean 
  in 
  its 
  nature, 
  maybe 
  soluble 
  or 
  insoluble 
  in 
  

   water, 
  may 
  be 
  yellow, 
  red, 
  blue 
  or 
  green 
  or 
  may 
  have 
  almost 
  any 
  

   color 
  but 
  in 
  all 
  its 
  insoluble 
  varieties 
  always 
  exhibits 
  plasticity 
  ; 
  

   that 
  is 
  if 
  brushed 
  in 
  a 
  pasty 
  state 
  upon 
  a 
  smooth 
  surface 
  its 
  par- 
  

   ticles 
  dry 
  in 
  optical 
  contact 
  and 
  with 
  brilliant 
  metallic 
  luster. 
  It 
  

   is 
  chemically 
  active." 
  The 
  second 
  is 
  intermediate 
  in 
  character, 
  

   may 
  be 
  yellow 
  or 
  green, 
  always 
  shows 
  metallic 
  luster, 
  is 
  never 
  

   plastic, 
  and 
  is 
  chemically 
  indifferent. 
  The 
  third 
  is 
  ordinary 
  silver. 
  

   In 
  1868 
  Carey 
  Lea 
  published 
  a 
  "Manual 
  of 
  ^Photography 
  " 
  which 
  

   reached 
  a 
  second 
  edition 
  in 
  1871. 
  

  

  Henry 
  Charles 
  Lea 
  the 
  eminent 
  historical 
  writer, 
  was 
  a 
  brother 
  

   of 
  Carey 
  Lea. 
  His 
  first 
  wife 
  was 
  a 
  Miss 
  Bakewell 
  of 
  Cincinnati 
  

   who 
  died 
  in 
  1881 
  leaving 
  a 
  son, 
  George 
  H. 
  Lea, 
  who 
  still 
  survives. 
  

   His 
  second 
  wife 
  was 
  Eva 
  Lovering, 
  a 
  daughter 
  of 
  the 
  late 
  Professor 
  

   Lovering 
  of 
  Harvard. 
  g. 
  f. 
  b. 
  

  

  Joseph 
  F. 
  James 
  died 
  on 
  the 
  29th 
  day 
  of 
  March 
  at 
  Hingham, 
  

   Mass. 
  Dr. 
  James 
  published 
  several 
  papers 
  on 
  botanical, 
  paleon- 
  

   tological 
  and 
  geological 
  subjects, 
  was 
  a 
  fellow 
  of 
  the 
  American 
  

   Association 
  for 
  the 
  Advancement 
  of 
  Science 
  and 
  an 
  original 
  

   fellow 
  of 
  the 
  Geological 
  Society 
  of 
  America. 
  

  

  