Story  of  the  Papaw. 
/Am.  Jour.  Pharm. 
I      August,  1901. 
might  bear  to  purified  pepsin.  Some  of  these  so  called  papains 
retain  the  waxy,  rubber-like  constituents  and  the  acrid,  irritating 
resins  of  the  milk. 
The  application  to  such  crude  material  of  the  term  "  papain,"  or 
any  similar  name  which  would  imply  the  isolated  ferment,  is  mis. 
leading  and  should  be  abandoned.  Tne  dried  juice  of  the  papaw,  or 
a  mixture  of  the  dried  juice  with  any  other  ferments,  should  be 
properly  labelled.  From  these  crude  preparations,  the  true  fer- 
ment can  be  separated  by  extraction  with  water  and  precipitation 
with  alcohol.  In  a  few  experiments  which  I  have  tried,  some  of 
the  crude  preparations  were  found  to  contain  about  twenty  per  cent, 
of  the  ferment-bearing  bodies  (albuminous). 
There  are,  however,  preparations  in  the  market  which  consist  of 
the  more  or  less  purified  and  separated  ferment,  or,  more  accurately 
speaking,  consisting  of  the  separated  proteids;  with  which  the 
ferments  are  associated. 
I  know  of  no  standard  by  which  these  market  preparations  can 
be  judged.  They  vary  greatly  in  their  proteolytic  action.  In  such 
as  may  be  prepared  by  simple  drying  of  the  milk,  no  two  lots  can 
be  alike.  These  will  be  found  to  vary  in  color,  to  emit  an  offensive 
odor  and  to  have  a  marked  acrid  disagreeable  taste,  producing,  in 
several  instances  in  my  experience,  quite  a  sharp  caustic  action. 
The  dried  papaw  juice  is  usually  the  more  energetic  in  the  begin- 
ning of  digestive  action  than  is  the  purified  ferment,  but  this  ener- 
getic action  of  the  dried  juice  apparently  soon  ceases,  while  the  pure 
ferment,  though  slower  in  immediate  action,  continues  its  activity 
for  many  hours.  Upon  treating  the  preparations  made  of  the  dried 
juice  with  ether,  chloroform,  benzine  or  alcohol,  evaporating  the 
solvent,  the  waxy  resinous  and  rubber-like  residue  elsewhere  spoken 
of  will  remain. 
The  amount  of  residue  left  after  extraction  with  water  may  be 
taken  as  a  rough  estimate  of  the  foreign  material  present,  the  fer- 
ment itself  being  associated  with  a  more  or  less  soluble  albumose. 
A  more  accurate  method  of  estimation  as  to  the  amount  of  ferment- 
bearing  bodies  is  as  follows : — Extract  a  weighed  portion  of  the 
powder  with  water  (two  or  three  successive  portions  with  tritura- 
tion) ;  combine  the  aqueous  solutions  and  saturate  with  crystals  of 
magnesium  sulphate  and  sodium  sulphate  in  about  equal  propor- 
tions.   If  the  solution  is  warmed  the  precipitate  will  be  quicker. 
