Am,  Jour.  Pharm.  1 
Feb.,  1881.  1 
Papaine. 
77 
furnished  a  papaine  containing  C  49*8,  50*3,  H  7*3,  7*4.  At  100°C., 
the  action  of  water  on  the  papaine  is  still  more  pronounced.  4  grams 
of  papaine^  dissolved  in  45  cubic  centimeters  of  water,  were  heated  in 
a  closed  vessel  for  ten  days  at  lOO^C,  the  liquid  depositing  0'084 
gram  of  a  precipitate  which  contained  but  0*0015  of  ash.  Precipi- 
tated by  alcohol,  this  solution  gave  a  brown  deposit  containing,  a  deduc- 
tion being  made  for  the  ash,  C  47'66,  H  8'14,  and  the  mother  liquor 
left  on  evaporation  an  amorphous  residue  weighing  1'114  gram.  Some 
experiments  may  be  finally  mentioned,  which  will,  perhaps,  throw 
some  light  on  the  mode  of  action  of  the  papaine. 
0*3  gram  of  papaine  was  dissolved  in  50  cubic  centimeters  of  water^ 
and  10  grams  of  fibrin  digested  with  this  solution ;  at  the  end  of  20 
minutes  the  liquid  was  expressed  and  the  fibrin  subjected  to  prolonged 
washing  with  cold  water.  In  the  liquid  obtained  by  the  expression  of 
the  fibrin  a  new  portion  of  15  grams  was  digested,  and  at  the  expira- 
tion of  half  an  hour  this  second  portion  of  fibrin  was  ex23ressed,  and 
washed  as  the  first.  Both  portions  (the  first  reduced  to  7  grams  bv 
the  commencement  of  digestion,  the  second  to  14  grams)  were  digested 
at  40°C.  with  pure  water,  when  both  became  dissolved,  the  second 
leaving  a  residue  of  4  grams  of  moist  dyspeptone. 
In  these  two  experiments  the  washings  had  certainly  removed  the 
dissolved  ferment,  and  the  washed  fibrin  would  not  have  been  able  to 
dissolve  except  by  the  action  of  a  portion  of  ferment  fixed  upon  it,  or 
perhaps  combined  with  it ;  the  ferment  fixed  upon  the  fibrin  in  an 
insoluble  state  had  then  redissolved  it  in  consequence  of  the  hydration 
of  the  fibrin. 
The  objection  could  be  made  that  the  ferment  is  retained  by  the 
fibrin  in  consequence  of  the  difficulty  of  causing  the  water  to  penetrate 
in  the  flocks,  and  in  response  to  this  objection  the  following  experi- 
ment has  been  made. 
Seventeen  grams  of  fibrin  were  cut  as  finely  as  possible  with  the 
scissors,  then  put  in  contact  with  a  weak  solution  of  papaine  for  ten 
minutes  at  ordinary  temperatures,  then  expressed  and  washed  for  half 
an  hour  under  a  strong  stream  of  water ;  finally,  ten  times  in  succes- 
sion, and  with  expression,  with  distilled  water.  The  last  wash  water, 
put  in  contact  at  40°C.  with  the  fibrin,  did  not  dissolve  from  one  day 
to  the  next  the  least  trace  of  these  substances.  The  fibrin  thus  treated 
and  washed  was  digested  at  40°C.  with  75  cubic  centimeters  of  pure 
water,  when  the  following  day  the  solution  was  complete,  with  the 
exception  of  a  residue  of  0*17  gram  of  dry  dyspeptone. 
