﻿130 
  

  

  Dr. 
  H. 
  H. 
  Dale. 
  

  

  Now, 
  in 
  the 
  nature 
  of 
  the 
  substances 
  which 
  produce 
  it, 
  in 
  the 
  conditions 
  

   which 
  destroy, 
  weaken 
  or 
  modify 
  their 
  action 
  as 
  antigens, 
  and 
  in 
  the 
  limits 
  

   of 
  its 
  specific 
  discrimination, 
  anaphylaxis 
  shows 
  a 
  remarkable 
  and 
  suggestive 
  

   similarity 
  to 
  the 
  well-known 
  type 
  of 
  immunity 
  dependent 
  on 
  the 
  so-called 
  

   " 
  precipitin 
  " 
  reaction.* 
  If 
  any 
  of 
  the 
  proteins 
  which 
  typically 
  produce 
  

   anaphylaxis 
  is 
  injected 
  in 
  suitably 
  large 
  doses 
  into 
  an 
  animal, 
  at 
  intervals 
  

   too 
  short 
  to 
  allow 
  the 
  appearance 
  of 
  a 
  definite 
  anaphylaxis, 
  the 
  injections 
  

   evoke 
  a 
  change 
  in 
  the 
  blood 
  serum 
  and 
  body 
  fluids 
  of 
  such 
  a 
  nature 
  that, 
  

   when 
  the 
  serum 
  or 
  other 
  fluid 
  is 
  mixed 
  with 
  a 
  solution 
  of 
  the 
  immunising 
  

   antigen, 
  often 
  in 
  very 
  high 
  dilutions, 
  a 
  mutual 
  precipitation 
  of 
  the 
  proteins 
  

   occurs. 
  The 
  precipitin 
  reaction 
  discriminates 
  between 
  individual 
  proteins, 
  

   such 
  as 
  those 
  from 
  a 
  serum, 
  just 
  as 
  the 
  anaphylactic 
  reaction 
  does. 
  One 
  other 
  

   example, 
  out 
  of 
  a 
  vast 
  number 
  available, 
  must 
  suffice 
  to 
  illustrate 
  the 
  close 
  

   correspondence 
  in 
  specificity 
  between 
  the 
  two 
  types 
  of 
  reaction. 
  Among 
  

   body 
  proteins, 
  that 
  of 
  the 
  crystalline 
  lens 
  occupies 
  a 
  peculiar 
  position 
  as 
  an 
  

   antigen. 
  Through 
  a 
  large 
  range 
  of 
  species 
  this 
  protein 
  acts 
  as 
  a 
  common 
  

   precipitating 
  antigen. 
  A 
  precipitating 
  serum, 
  prepared 
  by 
  immunising 
  an 
  

   animal 
  with 
  lens 
  proteins 
  from 
  the 
  eyes 
  of 
  horses, 
  will 
  form 
  precipitates 
  

   equally 
  well 
  with 
  lens 
  protein 
  from 
  ox, 
  cat, 
  man, 
  or 
  other 
  species, 
  including 
  

   even 
  that 
  to 
  which 
  the 
  animal 
  furnishing 
  the 
  serum 
  belongs. 
  The 
  lens, 
  cut 
  

   off 
  completely 
  from 
  the 
  circulation, 
  seems 
  to 
  behave 
  in 
  this 
  respect 
  as 
  

   though 
  its 
  constituents 
  were 
  alien 
  to 
  the 
  species. 
  As 
  an 
  anaphylactic 
  

   antigen 
  the 
  behaviour 
  of 
  the 
  lens 
  protein 
  is 
  exactly 
  similar 
  ;f 
  it 
  is 
  even 
  on 
  

   record 
  that 
  a 
  guinea-pig 
  has 
  been 
  rendered 
  anaphylactic 
  by 
  an 
  injection 
  of 
  

   protein 
  from 
  one 
  of 
  its 
  own 
  lenses, 
  and 
  subsequently 
  poisoned 
  by 
  injecting 
  

   protein 
  from 
  the 
  other. 
  

  

  A 
  large 
  volume 
  of 
  indirect 
  evidence 
  of 
  this 
  kind 
  strongly 
  suggests 
  that 
  the 
  

   antibody 
  causing 
  anaphylaxis 
  is 
  identical 
  with 
  the 
  so-called 
  precipitin. 
  

   But 
  there 
  is 
  one 
  obvious 
  and 
  apparently 
  fundamental 
  difficulty 
  in 
  the 
  way 
  

   of 
  assuming 
  their 
  identity. 
  The 
  serum 
  of 
  the 
  anaphylactic 
  guinea-pig 
  

   contains 
  no 
  demonstrable 
  precipitin 
  ; 
  that 
  is 
  to 
  say, 
  it 
  forms 
  no 
  visible 
  

   precipitate 
  when 
  mixed 
  with 
  the 
  sensitizing 
  antigen. 
  On 
  the 
  other 
  hand 
  

   the 
  animal 
  in 
  which, 
  as 
  the 
  result 
  of 
  repeated 
  injections, 
  a 
  strong 
  pre- 
  

   cipitating 
  quality 
  has 
  been 
  acquired 
  by 
  the 
  serum, 
  is 
  not 
  anaphylactic 
  but 
  

   immune. 
  

  

  The 
  difficulty, 
  however, 
  is 
  not 
  so 
  fatal 
  as 
  it 
  appears. 
  We 
  have 
  seen 
  that 
  

  

  * 
  Of. 
  Friedberger, 
  ' 
  Zeitschr. 
  f. 
  Immun.,' 
  vol. 
  2, 
  p. 
  208 
  (1909) 
  ; 
  Doerr 
  and 
  Buss, 
  

   ibid., 
  vol. 
  3, 
  p. 
  706 
  (1909). 
  

  

  f 
  Uhlenhuth 
  and 
  Andrejew, 
  ' 
  Arb. 
  aus 
  d. 
  k. 
  Gesundheitsanit,' 
  vol. 
  30, 
  No. 
  2 
  ; 
  Kraus, 
  

   Doerr, 
  and 
  Sohma, 
  ' 
  Wien. 
  klin. 
  Wochenschr.,' 
  vol. 
  21, 
  p. 
  1084 
  (1908). 
  

  

  