AniNo0vUri9Pisarni' }  Diphtheria  Antitoxin.  777 
alone.101  Chick  suggests  that  euglobulins  are  formed  by  associa- 
tion of  pseudoglobulin  with  a  lipoid.  Banzhaf  believes  a  separation 
of  the  serum  globulins  by  means  of  solubility  in  saturated  NaCl  is 
as  sharp  as  can  be  made  at  present.  The  euglobulins  precipitated 
from  horse  serum  by  saturation  with  NaCl  content  contain  no  anti- 
toxin.102 According  to  Dale  and  Hartley  the  purification  of  euglobu- 
lin  is  facilitated  by  its  insolubility  in  weakly  acidulated  water. 
Shaking  a  serum  with  air  is  said  to  produce  coagulation  and  de- 
naturation  of  the  euglobulin,  due  to  alteration  in  surface  energy, 
leading  to  absorption  of  albumin,  thus  rendering  the  euglobulins 
labile ;  they  then  coagulate  and  become  insoluble.  The  process  is 
not  due  to  oxidation.  Previous  heating  and  the  presence  of  a  hyper- 
tonic medium  tends  to  inhibit  the  effect  of  shaking,  but  dilution  with 
H20  or  storage,  rendering  the  euglobulins  labile,  favors  the  effect 
of  shaking.103  Fibrinoglobulin,  which  belongs  to  the  euglobulin 
fraction,  does  not  contain  the  antitoxin.104 
The  globulins  of  horse  serum  insoluble  in  water  (precipitating  on 
dialysis)  correspond  to  the  globulin  fraction  precipitated  by  28-36 
vol.  per  cent,  of  (NH4)2S04,  and  those  soluble  in  water  correspond 
to  the  fraction  precipitated  by  36-44  volume  per  cent.  (NH4)2S04.105 
According  to  Ide  and  Lemaire  the  antitoxin  is  all  precipitated  by 
from  26-44  per  cent.  (NH4)2S04.106 
Only  a  portion  of  the  globulins  seems  to  contain  or  carry  the  anti- 
toxin with  it.107  The  coagulation  temperature  for  the  "  soluble 
globulins  "  in  immune  serum  is  claimed  to  be  different  from  that 
in  non-immune;108  i.  e.,  in  normal  serum  it  ranges  from  65  to  71 0 
C,  but  in  immune  serum  it  begins  to  precipitate  at  71 0  C.  with  a 
maximal  coagulation  at  75 0  C.  According  to  Brunner  and  Pinkus109 
antitoxin  of  immune  serum  has  not  the  same  precipitation  limits  as 
the  globulins  of  normal  serum. 
101  Dale,  H.  H.,  and  Hartley,  P.,  Biochem.  Journ.,  Vol.  10,  p.  429,  1916. 
101a  Chick,  H.,  Biochem.  Journ.,  Vol.  8,  p.  404,  1914. 
102  Banzhaf,  E.  J.,  Johns  Hopkins  Hosp.  Bull.,  Vol.  22,  p.  106,  191 1; 
Banzhaf,  E.  J.,  and  Gibson,  R.  B.,  Journ.  Biol.  Chem.,  Vol.  3,  p.  253,  1907. 
103  Schmidt,  H.,  Journ.  Hyg.,  Vol.  14,  p.  399,  1914. 
104  pick. 
105  See  Ficker,  M.,  in  Kolle,  W.,  and  von  Wassermann,  A.,  "  Handb.  der 
path.  Mikro-organismen,"  Vol.  2,  part  1. 
106  Ide  and  Lemaire,  Arch,  internat.  Pharmacodyn.,  Vol.  6,  p.  477. 
1Q7  Belfanti,  S.,  and  Carbone,  T.,  Cent.  f.  Bakt.,  Vol.  23,  1898,  p.  907. 
108  Seng. 
109  Brunner,  J.,  and  Pinkus,  S.  N.,  Biochem.  Zeits.,  Vol.  5,  p.  381,  1907. 
