Am.  Jour.  Pharm.  > 
Aug,  1, 1873.  ) 
Pepsin. 
S59 
the  back  of  a  knife  or  ivory  paper  knife,  the  surface  was  scraped  very 
hard  in  order  that  the  glands  might  be  squeezed,  and  their  contents 
pressed  out.  The  viscid  mucus  thus  obtained  contains  the  pure  gastric 
juice,  with  much  epithelium  from  the  glands  and  surface  of  the  mu- 
cous membrane.  It  is  to  be  spread  out  on  a  piece  of  glass,  so  as  to 
form  a  very  thin  layer,  which  is  to  be  dried  at  a  temperature  of  100° 
over  hot  water  or  in  vacuo  over  sulphuric  acid.  Care  must  be  taken 
that  the  temperature  does  not  rise  much  above  100°,  because  the  ac- 
tion of  the  solvent  would  be  completely  destroyed.  When  dry,  the 
mucus  is  scraped  from  the  glass,  powdered  in  a  mortar,  and  trans- 
ferred to  a  well-stoppered  bottle." 
Several  persons  who  have  performed  experiments  with  this  (so 
called)  pure  digestive  powder,  including  Dr.  Beale  himself,  have  spoken 
highly  of  its  peptic  properties ;  and  from  their  position  we  cannot 
doubt  the  accuracy  of  their  experiments  and  statements.  In  my  own 
hands,  however,  I  cannot  say  the  results  were  so  satisfactory  as  1  had 
anticipated.  The  process,  too,  if  carried  out  strictly  according  to  Dr. 
Beale's  instructions,  is  a  very  wasteful  one,  more  pepsin  being  lost 
than  is  obtained ;  if,  on  the  other  hand,  it  is  attempted  to  obtain  a 
larger  quantity,  the  quality  is  reduced.  The  mucus  which  is  directed 
to  be  sponged  off,  and  which  is  usually  considerable  in  quantity,  pos- 
sesses about  one-third  to  one-half  the  activity  of  the  mucus  which  is 
afterwards  directed  to  be  scraped  off ;  then,  after  this  scraping,  a  con- 
siderable amount  of  pepsin  remains,  which  can  be  demonstrated  by  dis- 
solving it  out. 
Lastly,  we  have  the  process  of  Mr.  E.  Scheffer,  the  most  satisfac- 
tory as  regards  uniformity  of  excellence  and  economy  in  working  of 
any  I  have  tried.  It  has  been  detailed  in  this  Journal  so  recently*  I 
need  not  therefore  even  recapitulate  here.  It  can  be  made  to  answer 
strictly  to  the  tests  given;  it  keeps  well;  is  soluble  in  an  acidulated 
fluid,  and  hence  might  be  prescribed  in  solution  of  almost  any  strength. 
Amongst  other  experiments  one  was  performed  in  which  a  given  quan- 
tity of  the  moist  mucus  scraped  from  fresh,  cleansed  pigs'  stomachs, 
was  divided  into  equal  portions,  one  of  which  was  retained  moist,  ano- 
ther dried  in  a  thin  layer  at  a  temperature  not  exceeding  100°;  from 
a  third  portion  the  pure  pepsin  was  separated  by  Mr.  Scheffer's  pro- 
cess, but  adding  sufficient  sugar  of  milk  to  bring  it  to  the  exact  weight 
•of  the  portion  simply  dried. 
*See  American  Journal  of  Pharmacy,  Feb.  1872. 
