'^""sS"?im'"''}    Relative  Value  of  Different  Pepsin  Tests.  469 
sion  for  the  proportion  of  acidulated  water  to  be  used  with  a  pure 
pepsin. 
^'  On  the  basis  that  1  part  of  a  pure  pepsin  is  capable  of  dissolving 
1,000  times  its  weight  of  coagulated  egg  albumen  in  6  hours,  a  sac- 
charated pepsin  made  with  a  pure  pepsin  of  U.  S.  P.  strength  would 
contain  5  per  cent,  of  pure  pepsin  ;  therefore  if  1  grain  of  a  U.  S.  P. 
saccharated  pepsin  is  to  be  tested  in  the  presence  of  500  grains  of  acid- 
ulated water,  then  1  grain  of  a  pure  pepsin  should  be  tested  in  the 
presence  of  10,000  grains  acidulated  water,  to  equal  the  same  propor- 
tion of  water  and  acid  used  for  the  actual  quantity  of  pure  pepsin  con- 
tained in  a  U.  S.  P.  saccharated  pepsin  when  tested  according  to  the 
U.  S.  P." 
In  order  to  render  the  weighing  of  small  quantities  of  pure  pepsin 
as  easy  as  possible  to  the  pharmacist,  Manwaring  recommends  that  it 
should  be  saccharated,  and  for  this  purpose  he  gives  the  following 
recipe : 
Saccharated  pepsin  consisting  of: 
Pure  pepsin   1  gm. 
Milk  sugar  19  gm. 
To  make  the  test  take  of  the  above  saccharated  pepsin  0.3  gm. 
(=0.015  gm.  pure  pepsin). 
Coagulated  egg  albumen  22.5  gm. 
Acidulated  water  consisting  of : 
Distilled  water  100  cc. 
} 
Hydrochloric  acid  U.  S.  P.  1.25  ' 
The  eggs  are  to  be  boiled  for  15  minutes  and  the  whites  pressed  (by 
means  of  a  spatula)  through  a  (preferably  flat)  30  mesh  sieve.  For 
the  sake  of  uniformity,  the  egg  whites  should  be  cut  into  small  pieces 
and  thoroughly  mixed  before  being  passed  through  the  sieve. 
The  mixture  should  be  maintained  at  100-105°  F.  for  six  hours, 
and  agitated  thoroughly  about  every  half-hour. 
At  the  end  of  six  hours  the  temperature  of  the  bath  should  be 
quickly  run  up  above  145°  F.  to  destroy  the  pepsin,  then  the  bath 
with  contained  bottles  allowed  to  remain  undisturbed  over  night,  that 
the  undissolved  albumen  may  settle. 
If  the  test  bottle  has  been  kept  securely  corked  during  the  test,  or 
