Am.  Tour.  Pharm. 
Nov.,  19 18. 
Diph th eria  Antitoxin. 
767 
molecules  or  particles.  Antitoxin,  at  least  under  the  condition  as  we 
know  it,  does  not  dialyze  through  parchment  paper.15  We  have  no 
data  as  to  whether  certain  membranes  react  with  antitoxins  or  absorb 
them.16 
There  is  a  variable  loss  of  antitoxin  when  drawn  through  a 
Berkefeld  or  Chamberland  filter.  According  to  Dziergowski,  it 
passes  through  uninjured.17  Diphtheria  antitoxin  does  not  pass 
through  a  Chamberland  filter,  if  the  pores  are  closed  by  gelatin  and 
the  fluid  is  not  forced.18    It  is  held  back  by  gelatin  filters.19 
Diphtheria  antitoxin  is  retained  by  collodion  filters.20  The  dif- 
fusion constant  of  diphtheria  antitoxin  against  gelatin  at  +  6°  C. 
is  0.0015,  that  of  the  toxin  is  0.014,  and  of  NaCl  is  0.94,21  and  hence 
is  a  colloid,  at  least  in  the  form  we  meet  it,  or  so  intimately  asso- 
ciated with  colloids  as  to  react  with  them.  Taylor  believes  it  has 
more  colloidal  properties  than  its  toxin,  but  no  conclusions  regard- 
ing molecular  weight  by  the  use  of  Thovert's  relation  are  permis- 
sible.22 
According  to  Zunz,  charcoal  absorbs  as  much  toxin  as  antitoxin, 
but  not  the  combination  of  the  two.  Proteins  interfere  with  this 
absorption  and  BaS04  absorbs  the  toxin  to  a  slight  extent,  but  not 
the  antitoxin,  nor  their  combination,23  while  kaolin,  argile,  talc,r 
kieselguhr,  and  wood  charcoal  absorb  neither  diphtheria  toxin,  nor 
its  antitoxin,  nor  their  combination.  V.  Groer  and  Kassowitz  claiimi 
that  antitoxin  is  absorbed  by  a  kieselguhr  filter.24    Aluminium  sili- 
15  For  methods,  see  Gibson,  R.  B.,  Journ.  Biol.  Chem.,  Vol.  1,  p.  161, 
1905 ;  Pick,  E.  P.,  in  Krause,  R.,  and  Levaditi,  C,  "  Handbuch  d.  Immunitats- 
forschung,"  Vol.  1,  p.  534;  Seng,  W.,  Zeits.  f.  Hyg.,  Vol.  31,  p.  516,  1899; 
Welker,  W.  H.,  Biochem.  Bull.,  Vol.  2,  p.  70,  1912-13. 
16  See  Tschirch,  A.,  Arch.  Pharm.,  Vol.  252,  p.  537,  1914. 
17  Dziergowski,  J.,  Cent.  f.  Bakter.,  Vol.  21,  p.  333,  1897;  Di  Martini,  L., 
Cent.  f.  Bak.,  Vol.  24,  p.  360,  1898. 
18  Corbett,  L.,  Cent.  f.  Bakter.,  Vol.  24,  pp.  386,  415,  1898. 
19  Brodie,  T.  G.,  Journ.  Path.,  1897,  Vol.  4,  p.  464. 
20  Goucher,  L.,  Bull.  Sci.  Pharm.,  Vol.  19,  p.  129,  1913 ;  also  Bechhold, 
Biochem.  Zeits.,  p.  401,  Vol.  6,  1907;  Glenny,  A.  T.,  and  Walpole,  G.  S., 
Biochem.  Journ.,  Vol.  9,  p.  299,  191 5. 
21  Arrhenius,  A.,  "  Immuno-chemistry,"  p.  25,  1907. 
22  Taylor,  W.  W.,  "  Chemistry  of  Colloids,"  p.  309. 
23  Zunz,  E.,  Arch  Internat,  de  Physiol.,  Vol.  8,  p;  227,  1909. 
24  v.  Groer,  F.,  u.  Kassowitz,  K.,  Zeits.  f.  Immunitats.,  Vol.  22,  p.  447, 
1914. 
