358 
.Pepsin. 
5  Am.  Jour.  Phabm. 
I     Aug.  1,  1873. 
tive  results  ;  and  certain  is  it  that  wine  or  any  alcoholic  fluid  is  a  most 
unsatisfactory  vehicle  for  pepsin,  also,  that,  when  taken  with  food,  it 
unquestionably  retards  digestion.  The  above  experiment  was  several 
times  repeated,  first  with  portions  of  precisely  the  same  samples,  and 
also  with  samples  by  the  same  makers,  but  obtained  from  different 
sources ;  the  results  varied  slightly,  but  bore  the  same  relation  to 
each  other.  It  was  thought  desirable  not  to  obtain  the  samples  from 
the  manufacturers  direct,-  informing  them  of  the  purpose  for  which 
they  were  required,  but  all  were  obtained  from  authentic  sources. 
The  pepsin  Nos.  1  and  2  were  both  by  the  same  manufacturer,  and, 
as  it  will  be  seen,  were  of  good  quality,  but  it  is  somewhat  anomalous 
that  according  to  the  dose  given  the  former  should  have  been  about 
five  times  the  strength  of  the  latter,  whereas  it  would  appear  that 
there  is  little  difference  between  them.  The  catalytic  action  seems  to 
be  much  more  vigorous  in  the  early  part  of  the  process  of  digestion 
than  towards  the  end;  therefore,  had  a  larger  amount  of  albumen 
been  present  in  the  vial  No.  1,  it  is  possible  a  larger  amount  might 
have  been  dissolved,  and  the  residue  have  been  but  slightly  greater 
than  it  actually  was.  Nevertheless,  this  could  not  have  been  sufficient 
to  account  for  the  great  similarity  in  activity  of  the  two  specimens. 
Of  the  processes  for  its  preparation  as  a  medicinal  agent,  that  of 
precipitating  its  solution  by  acetate  of  lead,  and  subsequent  separa- 
tion of  the  lead  by  hydrosulphuric  acid,  has  probably  been  longest  in 
use,  but  its  activity  appears  to  be  more  or  less  injured  by  the  chemical 
treatment.  The  process  of  M.  Brucke,  consisting  of  solution  in  dilute 
phosphoric  acid,  neutralization  with  lime-water,  re-solution  in  dilute 
hydrochloric  acid,  and  final  treatment  with  cholesterin,  rectified 
spirit,  and  ether,  yields  a  product  possessing  active  peptic  properties, 
but  is  more  suitable  as  a  laboratory  experiment  than  for  the  purpose 
of  manufacture  on  a  commercial  scale.  Tannin  and  alcohol  have  both 
been  proposed  as  precipitants  for  pepsin,  but  I  am  not  aware  of  any 
definite  process  in  which  these  are  used  for  its  preparation  on  a  large 
scale.  Next  in  order  is  the  somewhat  primitive  process  of  Dr.  Beale. 
It  is  given  in  the  Pha7*maceutical  Journal,  N.  S.,  Yol.  II,  p.  684,  and 
is  as  follows  :— 
"  The  mucous  membrane  of  a  perfectly  fresh  pig's  stomach  was 
carefully  dissected  from  the  muscular  coat,  and  placed  on  a  flat  board. 
It  was  then  lightly  cleansed  with  a  sponge  and  a  little  water,  and 
much  of  the  mucus,  remains  of  food,  etc.,  carefully  removed.  With 
