Am.  Jour.  Pharm. 
Aug.,  1892. 
Proteids  of  Maize. 
431 
any  proteid  matter  to  boiling  water ;  possibly  it  was  formed  by  the 
hydrolysis  of  one  of  the  less  stable  globulins. 
Another  substance,  precipitated  by  the  addition  of  a  slight  excess 
of  very  dilute  hydrochloric  acid  to  the  sodium  chloride  solution  of 
the  undifferentiated  proteid  matter,  was  possibly  an  acid  globulin. 
It  contained  17-39  per  cent,  of  nitrogen. 
The  most  prominent  of  these  secondary  products,  however,  are 
certain  substances  insoluble  in  aqueous  sodium  chloride,  which  are 
invariably  formed  during  the  dialysing  operations  by  the  prolonged 
action  of  the  water  or  sodium  chloride  on  the  myosin  or  vitellin, 
which  in  this  respect  resemble  animal  myosin  and  certain  vegetable 
globulins.  When,  for  instance,  the  clear  sodium  chloride  extract  of 
maize  meal  is  dialysed,  the  precipitated  globulins  are  no  longer  com- 
pletely soluble  in  sodium  chloride  solution  ;  and  the  same  thing 
happens  when  the  globulins  are  precipitated  by  the  addition  of 
ammonium  sulphate  to  the  solution,  especially  if  the  sulphate  is 
somewhat  acid,  although  in  the  latter  case  the  insoluble  portion  of 
the  precipitate  may  contain  the  acid  globulin  mentioned  above.  In 
the  early  stages  of  transformation,  these  insoluble  substances 
resemble  the  alkali  albuminates,  for  they  dissolve  in  dilute  aqueous 
sodium  carbonate,  and  are  reprecipitated  on  neutralizing  the  solution  ; 
but  after  more  prolonged  action  they  seem  rather  to  resemble 
coagulated  proteid  matters.  Their  composition  is  fairly  uniform  ; 
the  mean  percentage  composition,  for  instance,  of  the  products 
formed  by  the  action  of  aqueous  ammonium  sulphate  or  water  on 
the  sodium  chloride  or  aqueous  extracts  of  maize  meal  and  subse- 
quent purification  was:  C,  5  3*45  ;  H,  6-99  ;  N,  1 6- 1 1  ;  S,  1-14;  so 
that  if  these  substances  are  formed  from  the  globulin,  the  latter 
must  undergo  considerable  modification.  The  change  is  not  due  to 
the  alkali  used  in  the  purification,  since  a  specimen  which  had  not 
been  purified  in  this  manner  was  found  to  contain  the  same  percent- 
age of  nitrogen.  Since  this  percentage  is  low,  it  is  probable  that 
the  insoluble  substances  are  formed  from  the  myosin  and  the  soluble 
globulin,  and  not  from  the  vitellin,  and  it  is  probably  this  tendency 
of  the  first  two  to  pass  into  such  insoluble  modifications  which 
facilitates  the  purification  of  the  vitellin. 
An  aqueous  or  sodium  chloride  extract  of  maize  meal  yields,  after  the 
three  globulins  and  the  soluble  salts  have  been  removed  by  dialysis, 
two  albumins  and  a  proteid  soluble  in  alcohol  (proteose).    The  solu- 
