Animal  Digestive  Ferments. 
( Am.  Jour.  Pharm. 
I      March,  1902. 
The  hydrochloric  acid  of  the  gastric  juice  we  know  does  not  exist 
as  free  acid,  but  is  in  some  way  bound  up  to  the  proteids,  this  acid 
again  uniting  with  the  proteids  and  bases  of  foods  and  displacing 
organic  acids.  So  that  we  must  be  mindful  of  the  distinction  exist- 
ing between  the  acid  of  pure  gastric  juice  and  the  acid  contents  of 
the  digesting  mass. 
Seeing  that  the  gastric  juice  is  essentially  an  acid-pepsin  secre- 
tion, it  might  be,  and  indeed  it  generally  has  been  presumed,  that 
solutions  containing  hydrochloric  acid  of  the  percentage  of  gastric 
juice  would  constitute  favorable  vehicles  for  the  peptic  ferment,  as 
pharmaceutical  products.  But  a  mixture  of  pepsin,  hydrochloric 
acid  and  water  has  not  the  stability  of  gastric  juice ;  it  differs  there- 
Irom  in  important  particulars- — in  the  absence  of  proteids  associated 
with  pepsin  and  united  with  the  acid,  and  in  the  absence  of  inor- 
ganic constituents  of  the  gastric  juice;  and  we  must  consider  gastric 
juice  in  its  entity  as  being  of  a  peculiar  composition,  essential  and 
indispensable  to  the  complete  exhibition  of  its  function. 
Pepsin  in  solution  with  hydrochloric  acid  of  the  percentage  of 
normal  gastric  juice,  if  brought  in  contact  with  albumen,  digests  it 
with  facility,  but  here  a  portion  of  the  acid  is  immediately  united 
with  the  albumen  and  with  the  alkali  of  the  albumen.  If,  however, 
we  submit  pepsin  to  long-continued  contact  simply  in  this  dilute 
hydrochloric  acid  we  find  the  pepsin  to  progressively  deteriorate 
in  activity.  Therefore,  acid  cannot  with  impunity  be  added  to  pep- 
sin in  solution  in  the  manufacture  of  products  necessarily  to  be  sub- 
mitted to  conditions  of  commerce. 
The  pancreas  gland  contains  four  distinct  ferments.  Its  proteo- 
lytic enzyme  is  probably  not  elaborated  in  an  active  form,  but 
becomes  endowed  with  vitality  by  contact  of  the  pancreas  juice 
with  the  acids  of  the  chyme,  which  are  undoubtedly  organic  in  a 
very  considerable  degree,  and  are  known  to  be  powerful  developers 
of  the  latent  energy  or  vitality  of  the  pancreas  trypsinogen. 
The  diastasic  ferment  undoubtedly  exists  pre  formed,  and  we 
know  of  no  reason  to  assume  that  it  requires  to  be  developed,  nor 
of  any  chemical  or  physiological  data  which  would  indicate  this 
view. 
The  fat-digesting  ferment  varies  greatly  in  the  glands  of  different 
animals,  and  its  action  upon  fat  in  reducing  fat  globules  to  a  minute 
form  is  difficult  to  account  for,  especially  as  the  ferment  is  not  in 
