Am.  Jour.  Pharm.  \ 
March,  1902.  J 
Animal  Digestive  Ferments. 
ii3 
destroyed  when  prepared  with  the  best  of  purpose ;  and  this  in  a 
way  which  does  not  at  all  exist  as  regards  chemical  preparations, 
simply  from  the  universally  recognized  facts  as  to  the  compatibility 
and  reactions  of  chemicals.  It  will  be  interesting  to  mention  a  few 
instances  for  their  present  practical  importance  : 
It  happened  that  Scheffer's  interest  in  the  subject  was  co-existent 
with  the  "  elixir "  mania,  when  the  tendency  was  to  produce  as 
many  combinations  as  possible,  rather  than  to  ascertain  those  most 
eligible  for  this  form  of  exhibition.  Naturally,  pepsin  and  pan- 
creatine did  not  escape. 
SchefTer  insisted  on  the  incompatibility  of  bismuth  in  solution 
with  pepsin.  The  writer  has  without  success  endeavored  to  pre- 
pare a  solution  which  should  retain  pepsin  in  a  vital  form  in  con- 
tact with  bismuth  in  solution  for  a  sufficient  length  of  time  to 
justify  its  issuance  as  a  pharmaceutical  product.  Compounds  of 
pepsin  and  bismuth  in  solution  are  yet  in  commerce,  and  have  a 
place  in  formularies. 
That  the  ferments  combined  in  solution  are  antagonistic  to  each 
other  has  often  been  pointed  out.  SchefTer  early  called  attention 
to  the  incompatibility  of  pepsin  and  pancreatine,  and  pepsin  and 
diastase  in  elixirs.  It  is  impossible  to  prepare  any  media  suitable  for 
the  preparation  of  the  enzymes  of  the  stomach  and  pancreas  in  com- 
bination in  solution ;  for  whether  the  reaction  of  the  preparation  be 
neutral,  alkaline,  or  acid,  there  will  be  a  gradual,  sure,  progressive 
deterioration  of  the  product  under  the  commercial  conditions  to 
which  the  preparation  must  be  submitted.  If  the  liquid  preparation 
of  the  mixed  peptic  and  pancreatic  ferments  be  neutral  or  alkaline, 
the  pepsin  becomes  destroyed  ;  if  acid,  all  but  the  pepsin  perish,  and 
the  acid  compound  will  therefore  be  found  to  be  devoid  of  any  pan- 
creatic activity — capacity  to  convert  starch,  or  to  convert  proteids 
in  neutral  or  alkaline  media. 
On  the  other  hand,  it  is  a  fact  that  suitable  solutions  of  peptic  and 
pancreatic  ferments  can  be  mixed  extemporaneously  and  found  to 
retain  the  virtues  of  the  component  ferments  for  a  sufficient  length 
of  time  for  their  use  in  the  ordinary  method  of  prescribing. 
The  role  of  hydrochloric  acid,  since  Schwann's  time  (both  its 
normal  function  and  the  limitations  of  its  compatible  percentage) 
has  become  thoroughly  known;  yet  free  mineral  acids  in  destructive 
degree  to  the  enzymes  are  often  used  in  pharmaceutical  prepara- 
