^™NoT^i882™'}  Action  of  Digestive  Ferments  upon  Drugs.  575 
pared,  and  as  soon  as  the  infusion  had  cooled  to  50°C.,  some  of  the 
acid  solution  of  pepsin  was  added  and  the  temperature  maintained  by 
means  of  the  incubator  for  two  hours ;  47  jier  cent,  of  the  rhubarb 
was  thus  rendered  soluble.  The  mixture  was  then  neutralized  by 
sodium  carbonate,  the  alkaline  solution  of  pancreatin  added,  and  the 
temperature  sustained  for  two  hours  longer.  The  insoluble  portion 
was  then  found  to  consist  of  cellulose  and  earthy  salts,  retaining  a 
small  quantity  of  coloring  matter.  The  240  grains  of  rhubarb  left  an 
insoluble  residue  of  96  grains. 
Infusion  of  calumba,  prepared  with  boiling  water,  and  passed  through 
the  same  processes  of  digestion,  gave  somewhat  similar  results.  The 
spongy  cellulose  was  associated  with  a  trace  of  berberia  ;  500  grains 
of  calumba  left  an.  insoluble  residue  of  172  grains. 
Cinchona  and  opium,  upon  the  other  hand,  behaved  somewhat  dif- 
ferently ;  the  gummy  and  extractive  matters  were  dissolved  and 
retained  in  solution,  but  a  considerable  portion  of  the  alkaloids  was 
left  in  the  insoluble  marc.  Cinchona  was  about  half  soluble  (48  per 
cent.),  and  opium  about  two-thirds,  or  68  j^er  cent.  Quinine  and  mor- 
phia could  be  detected  in  the  respective  solutions  and  were  also  readily 
found  and  extracted  from  the  insoluble  residues.  The  cinchona  tannin 
was  destroyed  in  the  digestive  process  and  failed  to  precipitate  gelatin, 
but  this  peculiarity  will  be  noticed  when  we  come  to  the  action  upon 
definite  substances. 
The  possibility  of  the  digestive  ferments  attacking  gum  acacia  was 
deemed  of  some  importance,  in  consequence  of  gum  being  used  in  a 
test  demonstrating  the  acidification  of  fat  by  the  emulsive  ferment  of 
the  pancreas.  Strong  solutions  of  white  gum  arable  were  therefore 
prepared  and  submitted  in  the  incubator  to  the  action  of  the  gastric 
and  pancreatic  solutions.  The  feebly  acid  solution  containing  the  gas- 
tric ferment  remained  clear  even  after  several  hours'  digestion.  A 
slight  change,  however,  had  occurred  in  the  mixture,  as  a  portion 
removed,  neutralized  with  Svoda  and  boiled  with  Fehling's  sugar  test, 
showed  a  slight  reduction  to  cuprous  oxide,  whereas  a  portion  of  the 
original  solution  undigested,  but  kept  at  the  same  temperature  and 
under  similar  conditions,  was  not  affected  by  the  glucose  test. 
The  nmcilage  digested  with  the  alkaline  pancreatin  solution  soon 
became  cloudy,  and  ultimately  a  white  precipitate  was  formed.  The 
mixture  seemed  less  viscid  than  that  containing  the  gastric  ferment, 
and  a  portion  of  the  solution  gave  the  violet  reaction  of  pe])tone.  Tlie 
