﻿b 
  PROCEEDINGS 
  OF 
  THE 
  CALIFORNIA 
  

  

  number 
  of 
  concentric 
  shells 
  of 
  equal 
  volumes 
  with 
  each 
  other, 
  to 
  find 
  the 
  diam- 
  

   eters 
  of 
  the 
  consecutive 
  inner 
  shells 
  of 
  equal 
  volumes 
  with 
  the 
  subdivided 
  shell. 
  

  

  Let 
  d', 
  d 
  ; 
  x, 
  y, 
  etc 
  , 
  and 
  p, 
  represent 
  the 
  quantities 
  as 
  before 
  ; 
  n 
  the 
  required 
  

   number 
  of 
  inner 
  shells, 
  and 
  i', 
  i", 
  i'", 
  etc 
  , 
  the 
  consecutive 
  diameters 
  of 
  these 
  

   shells 
  ; 
  then, 
  

  

  . 
  3 
  _ 
  (w 
  + 
  jn) 
  fZ3 
  — 
  n 
  f/'3 
  

  

  Dr. 
  Stout 
  submitted 
  specimens 
  of 
  iron 
  sands, 
  such 
  as 
  he 
  had 
  ex- 
  

   hibited 
  at 
  a 
  previous 
  meeting. 
  A 
  microscopic 
  examination 
  was 
  

   made 
  by 
  the 
  members, 
  and 
  a 
  discussion 
  as 
  to 
  the 
  formation, 
  depo- 
  

   sition 
  and 
  occurrence 
  of 
  these 
  sands, 
  Avas 
  participated 
  in 
  by 
  Drs. 
  

   Stout 
  and 
  Gibbons 
  ; 
  also 
  by 
  Prof. 
  Davidson, 
  who 
  mentioned 
  their 
  

   occurrence 
  in 
  the 
  neighborhood 
  of 
  the 
  Chilchat 
  River 
  ; 
  and 
  Mr. 
  

   Dall, 
  who 
  spoke 
  of 
  samples 
  of 
  black 
  sand 
  from 
  Alaska, 
  sent 
  to 
  him 
  

   some 
  time 
  ago 
  for 
  examination, 
  which 
  he 
  was 
  surprised 
  to 
  find 
  con- 
  

   tained 
  hardly 
  any 
  magnetite. 
  

  

  Eegular 
  Meeting, 
  February 
  3d, 
  1873. 
  

   President 
  in 
  the 
  Chair. 
  

  

  William 
  E. 
  Brown, 
  Frederick 
  H. 
  Waterman, 
  Rev. 
  W. 
  A. 
  

   Scott, 
  D.D., 
  were 
  elected 
  resident 
  members. 
  

  

  Hon. 
  C. 
  E. 
  DeLong, 
  and 
  Albert 
  Bierstadt, 
  were 
  elected 
  corre- 
  

   sponding 
  members. 
  

  

  Donations 
  to 
  the 
  Library 
  : 
  Report 
  of 
  the 
  Medical 
  Society 
  of 
  Cal- 
  

   ifornia, 
  for 
  1871-2, 
  Transactions 
  and 
  Proceedings 
  of 
  the 
  New 
  

   Zealand 
  Institute, 
  1871, 
  Vol. 
  IV 
  ; 
  Fishes 
  of 
  New 
  Zealand, 
  etc., 
  

   by 
  F.W. 
  Hutton, 
  and 
  Notes 
  on 
  the 
  Edible 
  Fishes 
  of 
  New 
  Zealand, 
  

   by 
  James 
  Hector, 
  M. 
  D., 
  presented 
  by 
  Victor 
  Hector. 
  Proceed- 
  

   ings 
  Agassiz 
  Institute 
  of 
  Sacramento, 
  1872. 
  

  

  Donations 
  to 
  the 
  Museum 
  : 
  A 
  barbed 
  instrument, 
  made 
  by 
  the 
  

   natives 
  of 
  Kotzebue 
  Sound, 
  from 
  A. 
  Honcharenko. 
  Specimen 
  of 
  

   silver 
  ore 
  from 
  the 
  Raymond 
  and 
  Ely 
  mines. 
  Specimens 
  of 
  " 
  ce- 
  

  

  