ON  PEPSINE. 
263 
ON  PEPSINE, 
By  W.  Stevens  Squire,  Ph.  D. 
Some  time  since  a  new  medicine,  under  the  name  of  pepsine, 
was  introduced  in  Paris,  and  was  extensively  used  there  by  Dr. 
Corvisart  and  others,  apparently  with  considerable  success  in 
dyspepsia  and  certain  cases  of  consumption.  This  preparation 
consists  principally  of  a  substance  well  known  to  Chemists  and 
Physiologists,  the  nature  and  composition  of  which,  however,  is 
but  imperfectly  made  out.  It  is,  in  fact,  to  a  principle  termed 
pepsine  that  the  gastric  juice  chiefly  owes  its  property  of  con- 
verting meat  and  other  matters  received  into  the  stomach,  into  a 
form  in  which  they  can  be  readily  assimilated. 
By  the  term  gastric  juice  is  understood  a  fluid  secreted  by  the 
stomach,  and  poured  into  it  through  a  number  of  minute  tubes, 
situated  in  the  mucous  membrane  which  forms  the  interior  coat. 
These  tubes  are,  during  fasting,  plugged  up  by  a  mass  of  epithelial 
cells  ;  but  when  the  mucous  membrane  is  irritated  by  food  or  by 
certain  other  stimulants — pepper,  for  example— the  secretion  of 
gastric  juice  commences,  the  plugs  of  epithelium  are  expelled, 
and  the  juice  distils  into  the  cavity  of  the  stomach. 
Gastric  juice  contains  about  97  per  cent,  water,  1.25  per  cent, 
pepsine,  and  1.75  per  cent,  salts,  consisting  of  carbonate  and 
phosphate  of  lime,  chloride  of  sodium,  minute  traces  of  sulphates, 
and  sometimes  a  trace  of  ammoniacal  salts.  The  proportions, 
however,  in  which  these  inorganic  constituents  are  present,  vary 
considerably.  Lastly,  the  gastric  juice  contains  a  free  acid, 
which  is  one  of  the  most  important  components. 
As  it  would  be  impossible  to  obtain  a  sufficient  quantity  of 
gastric  juice  for  medicinal  purposes  from  living  animals,  either 
by  fistulous  openings  or  any  other  method,  we  seek  to  intercept 
the  pepsine  before  it  passes  into  the  stomach,  and  to  extract  it 
from  the  little  tubes  in  which  it  is  secreted,  or  at  all  events  along 
which  it  passes  on  its  way.  For  this  purpose  the  rennet-bags 
of  sheep  are  the  most  convenient,  on  account  of  the  large  supply 
which  is  always  at  hand ;  and  the  following  process  has  been  pro- 
posed by  M.  Boudault : — The  rennet-bags  are  opened  and  re- 
versed, and  washed  under  a  thin  stream  of  water,  to  free  them 
from  alimentary  matters,  &c.    The  mucous  membrane  is  then 
