572 
Action  of  Papain. 
/Am.  Jour.  Pharm. 
I      Nov.,  1885. 
from  the  unsaturated  filtrate,  namely,  a  marked  biuret  reaction  with 
copper  sulphate  and  potash,  and  a  cloudiness  with  corrosive  sublimate, 
insoluble  in  excess ;  boiled  with  fresh  ferric  acetate  and  filtered,  no 
proteid  was  found  in  the  filtrate,  showing  the  absence  of  peptones. 
Hence  this  body,  which  is  soluble  in  saline  solutions,  and  precipitated 
from  these  by  saturation  with  sodium  chloride,  and  giving  a  biuret 
reaction,  is  a  hemialbumose. 
This  point  being  settled,  experiments  were  done  to  see  the  degree  of 
miction  of  the  ferment  in  the  milk.  In  the  following  experiment,  the 
digestion  of  the  curds  (casein  and  fat),  obtained  by  precipitating  200  cc. 
of  milk  diluted  with  glacial  acetic  acid,  was  compared  with  that  of 
the  same  quantity  of  milk.  The  curd  was  well  washed,  to  free  from 
iicid,  and  squeezed  as  dry  as  possible  before  weighing. 
A. 
Milk   200  cc. 
Soclic  carbonate   -5  gram  (7^  grains). 
Water   200  cc. 
Papain    -3  gram  (5  grains). 
The  water  and  sodic  carbonate  were  boiled  and  added  to  the  milk 
(which  was  at  10°C.);  resulting  tem23erature,  50°C.  The  papain  was 
then  stirred  in  the  beaker,  wrapped  up,  and  kept  in  a  warm  place. 
In  ten  minutes  the  mixture  began  to  curdle,  the  curds  gradually  dis- 
solving ;  in  forty-five  minutes,  a  slight  bitter  taste  was  developed ;  in 
fifty  minutes,  the  temperature  of  the  liquid  was  35°C.  It  was  then 
boiled,  causing  a  slight  precipitate.  The  filtered  liquids  gave  the  tests 
for  peptones. 
B. 
Curd  prepared  as  above  from  200  cc. 
of  milli  ;  weiglit   21-5  grams. 
Water   200  cc. 
Sodic  carbonate   "5  gram  (7^  grains). 
Papain   -5  gram  (7i  grains). 
Half  the  water  was  boiled  and  added  to  the  other  half,  containing 
the  curd  and  sodic  carbonate;  resulting  temperature  48 °C.  It  was 
placed  in  a  warm  place  under  cover  for  sixty-five  minutes,  when  the 
residue  of  curd  weighed  only  2*7  grams;  therefore  (21*5 — 2'7)=18*8 
grams  digested.  The  residue  was  chiefly  fat ;  it  dissolved  almost  com- 
pletely in  ether.  The  filtrate  after  digestion  gave  a  slight  precipitate 
W'ith  acetic  acid  in  the  cold,  soluble  in  excess;  none  on  boiling;  a 
jnarked  biuretic  reaction  with  copper  sulphate  and  potash. 
