346 
Notes  on  Pepsin,  Bismuth,  etc. 
{  Am.  Jour.  Pharm. 
I    Aug.  1,  1872. 
zine  ;  II,  crystallized  from  alcohol,  and,  III,  obtained  by  heating  the 
oily  compound  of  the  first  mother-liquor  to  260°  C.  and  crystallizing 
from  petroleum  benzine. 
NOTES  ON  PEPSIN,  BISMUTH,  AND  ELIXIR  OF  PEPSIN  AND 
BISMUTH. 
By  E.  Soheffer. 
Several  facts  which  I  published  in  my  essay  (Am.  Jour.  Phar.,  Feb., 
1872),  impressed  on  me  the  impossibility  of  a  preparation  such  as 
elixir  pepsin,  bismuth,  (and  strychnine.)  I  do  not  want  to  speak 
again  about  the  presence  of  alcohol  in  a  solution  containing  pepsin, 
as  I  have  repeatedly  given  the  results  of  my  experiments,  which 
prove  beyond  doubt  that  pepsin  and  alcohol,  particularly  when  the 
latter  amounts  to  a  certain  percentage,  are  incompatible. 
The  main  objection  I  intended  to  bring  against  such  an  elixir,  pre- 
pared with  ammonio-citrate  of  bismuth  in  a  neutral  or  alkaline  solu- 
tion, is  the  neutral  or  slightly  alkaline  state.  My  experiments  prove 
clearly  that  pepsin,  in  neutral  solution,  does  not  keep,  and  that  in 
alkaline  solution  it  loses  its  digestive  properties.  In  how  minute 
quantities  the  presence  of  an  alkali  destroys  the  digestive  properties 
of  pepsin,  will  be  shown  by  the  following  experiments,  quite  recently 
made. 
Having  once  taken,  instead  of  distilled  water,  of  our  well  water — 
which  contains  carbonate  of  lime  and  magnesia — to  swell  the  pepsin, 
before  the  acid  wa3  added,  I  was  astonished  to  find  that  the  pepsin 
did  not  act  on  albumen.  This  caused  me  to  repeat  the  experiment 
simultaneously  with  others  for  control. 
A.  Pepsin  swelled  in  distilled  water ;  the  acid  (6  drops  of  muriatic 
acid  to  the  fluid  ounce)  added  afterwards. 
B.  Pepsin  swelled  in  well-water,  and  6  drops  of  acid  added  to  1 
oz.  after  2  hours. 
C.  Pepsin  swelled  in  distilled  water,  which  was  before  shaken  with 
carbonate  of  magnesia,  for  two  days,  and  then  filtered ;  6  drops  of 
acid  added  after  two  hours. 
D.  Pepsin  dissolved  in  acidulated  well  water. 
Of  these  four  experiments  each  contained  the  same  amount  of  acid, 
the  same  amount  of  pepsin,  and  to  each  vial  the  same  amount  of  co- 
agulated albumen  was  given.  After  having  been  exposed  to  a  tem- 
perature of  105°  Eahr.  for  six  hours,  in  A  and  D  all  the  albumen 
