420 
So dio- Bismuth  Tartrate  and  Pepsin. 
j  Am.  Jour.  Phaim. 
\      Sept.,  1885. 
and  its  odor  and  taste  are  therefore  comparably  bad.  A  solution  of 
pepsin  is  also  official,  but,  in  the  writer's  opinion,  this  is  too  acid  and 
too  dilute.  The  proportion  of  glycerin,  when  a  full  dose  is  given,  is 
so  great  that  it  cannot  fail  to  cause  gastric  distress.  The  proportion 
of  pepsin  can  easily  be  tripled  or  quadrupled  so  that  then  a  maximum 
dose  will  not  contain  an  excesssive  amount  of  glycerin.  All  indica- 
tions tend  to  show  that  pepsin  in  very  acid  solutions  soon  deteriorates. 
It  has  been  asserted  with  much  stress  that  alkalies  destroy  pepsin. 
This  is  true  only  of  very  concentrated  alkali ;  weak  alkali,  under  a 
moderate  period  of  exposure,  does  not  perceptibly  injure  pepsin. 
The  pepsin  whilst  in  the  gastric  glands  is  neutral,  and  possibly  alka- 
line. It  becomes  acid  only  as  it  emerges  from  the  ducts.  Further- 
nlore,  the  chief  activity  of  the  natural  pepsin  is  exerted  on  the  par- 
tially digested  proteids  after  their  entry  into  the  alkaline  intestinal 
fluids.  In  many  cases  of  gastric  disturbance  the  cause  is  said  to  be 
an  excess  of  the  natural  acidity.  On  such  occasions,  an  additional 
increment  introduced  Avith  the  pepsin  must  be  prejudicial  than  other- 
wise. Hence,  for  these  various  reasons,  the  writer  believes  that,  in 
addition  to  enhanced  concentration,  the  solution  should  contain  a  mini- 
mum pro|)ortion  of  acid,  consistent  with  complete  solution  of  the 
pepsin. 
The  Pharmacopoeia  allows  only  24  hours  for  the  solution  of  the 
pepsin,  which  time  appears  insufficient.  The  writer,  however,  pro- 
poses an  entirely  new  method,  by  means  of  the  agency  of  heat.  Under 
this  new  procedure  one  part  of  saccharated  pepsin  will  perfectly  dis- 
solve during  less  than  one  hour's  time  in  four  parts  of  water  contain- 
ing one-eighth  part  of  diluted  chlorhydric  acid,  at  a  temperature  not 
materially  exceeding  40°C.  The  resulting  solution  obtained  with  a 
pepsin  practically  free  from  mucus  will  be  void  of  sediment  and  but 
slightly  opalescent.  It  will  filter  with  uniform  but  only  moderate 
speed  to  the  end,  and  better  without  than  with  glycerin.  The  first 
portions  passing  through  the  filter  are  always  turbid,  and  must  be 
returned  until  the  liquid  drops  perfectly  clear.  The  glycerin  is  added 
to  the  filtrate  in  the  j^roportion  of  a  third  or  not  less  than  three-tenths 
of  the  whole  volume  after  mixture.  The  solution  should  represent  one 
gram  of  saccharated  pepsin  in  eight  cc.  or  fluid  grams.  The  prepa- 
ration is  much  improved  by  employing  orange  flower  water  in  the 
proportion  of  one-fourth  of  the  finished  volume.  When  a  pepsin 
containing  an  admixture  of  mucus  is  used  this  impurity  settles  rather 
