772 
Diphtheria  Antitoxin. 
Am.  Jour.  Pharm. 
Nov.,  1918. 
antitoxin.68  Aluminium  sulphate  and  ammonia  precipitate  about 
95  per  cent,  of  the  antitoxin  from  serum.69  We  have  no  published 
data  as  to  the  action  of  uranyl  acetate  or  of  phosphotungstic  acid 
on  antitoxin.  The  former  has  been  used  by  Brieger  in  attempts  to 
isolate  tetanus  toxin. 
Brieger  and  Boer  have  used  heavy  metals  in  their  work  on  the 
isolation  of  diphtheria  antitoxin.  Neutral  lead  acetate  with  a  trace 
of  NH4HO  precipitates  albumin  from  serum,  but  the  antitoxin  re- 
mains in  the  filtrate.  This  can  then  be  precipitated  by  shaking  with 
(NH4)2S04,  but  the  results  are  variable,  owing  to  the  solubility  of 
the  Pb  combination.  Brieger  and  Boer  believe  that  antitoxin  forms 
some  combination  with  certain  heavy  metals  and  that  this  combina- 
tion is  soluble  in  alkalies.  HgCl2  will  precipitate  it  if  Nad  has 
been  added  to  the  solution.70  CdS04  precipitates  50  per  cent,  anti- 
toxin, and  CuS04  has  also  been  used  as  a  precipitant. 
Platinum  chloride  precipitates  it.71 
A  solution  of  copper  acetate  (1  per  cent.)  causes  a  precipitate 
from  antitoxic  serum.  This  when  dissolved  by  means  of  Na2C03 
and  treated  with  C02  to  remove  Cu,  is  found  to  have  antitoxic 
properties.  However,  the  filtrate  also  contains  some  of  the  ac- 
tivity.72 
Nucleohiston  precipitates  antitoxin.73 
Nucleoproteins  from  various  tissues  possess  antigenic  proper- 
ties.74 
It  has  been  suggested  that  there  was  some  connection  between  the 
specific  ferments  of  the  blood  and  antibodies,  but  according  to  Bron- 
fenbrenner — "  No  definite  proof,  however,  of  such  an  identifica- 
tion has  been  offered."75 
Some  of  the  work,  which  has  been  done  on  the  chemistry  of  the 
diphtheria  antitoxin,  would  suggest  that  this  antitoxin  is  not 
a  protein,  thus  Proscher  thought  he  could  obtain  an  antitoxin  free 
68  Aronson. 
69  Brieger  and  Boer,  also  Aronson. 
70  Brieger  and  Boer. 
71  Belfanti,  S.,  and  Carbone,  T. 
72  Nikanorow,  P.  J.,  in  Jahresber.  u.  d.  Fort.  d.  Tier-chemie  t  Vol.  26,  p. 
983,  1897. 
73  Freund,  E.,  Grosz,  S.,  and  Jelinck,  O.,  Cent.  f.  inn.  Med.,  Vol.  16,  pp. 
913,  937>  1895 ;  Tichomiroff,  M.,  Zeits.  f.  Physiol.  Chem.,  Vol.  21,  p.  90. 
74  Wells,  H.  G.,  Joum.  Biol.  Chem.,  1916,  28,  p.  11. 
75  Bronfenbrenner,  J.,  Joum.  Exper.  Med.,  Vol.  21,  p.  222,  1915. 
