114 
Animal  Digestive  Ferments. 
Am.  Jour.  Pharm. 
March,  1902. 
tions.  And  it  has  been  even  possible  now  for  the  assertion  to 
receive  publication  that  hydrochloric  acid  is  the  real  digestant  of 
albumen  in  the  pepsin  test. 
Alcohol  and  glycerin  in  relation  to  the  ferments  are  so  important 
that  they  should  receive  attention. 
In  order  to  preserve  the  enzymes  in  solution,  some  antiseptic 
must  be  employed,  and  alcohol  and  glycerin  prove  the  most  desir- 
able for  pharmaceutical  preparations  of  the  enzymes,  as  they  are  in 
galenical  preparations  in  general.  The  value  of  glycerin  in  the 
extraction  and  preservation  of  the  enzymes  is  well  known;  we  would 
say,  however,  that  we  cannot  regard  concentrated  glycerin  as  being 
favorable  for  direct  gland  extraction  ;  dilution  with  water  is  advan- 
tageous. 
A  great  deal  of  misconception  has  existed  regarding  the  relation 
of  alcohol  to  the  digestive  ferments,  especially  as  to  the  pharma- 
ceutical and  therapeutic  significance  of  the  facts,  that  strong  alcohol 
precipitates  pepsin ;  that  pepsin  does  not  digest  well  in  the  presence 
of  diluted  alcohol. 
The  writer,  in  his  "  Hand-Book  of  the  Digestive  Ferments,"  pub- 
lished in  1892,  pointed  out  that  alcohol  retarded  digestion  in  vitro 
simply  for  the  reason  that  alcohol  is  not  a  media  either  for  the 
activity  of  pepsin  or  for  the  solution  of  the  products  of  digestion ; 
that  water  is  the  prrysiological  media  in  which  the  ferment  performs 
its  functions  and  by  which  the  products  of  digestion  are  taken  up  as 
they  are  formed.  And  in  his  experiments  with  the  influence  of 
various  agents  upon  digestion,  he  showed  that  glycerin,  peptone, 
sugar,  and  other  substances,  likewise  retarded  digestion,  not  because 
they  exerted  in  themselves  any  injurious  influence  whatever  upon 
the  ferments,  but  simply  in  the  degree  to  which  they  diminished  the 
proportion  of  water  and  its  consequent  capacity  as  a  media. 
The  products  of  digestion  all  clog  the  action  of  the  enzyme  by 
which  they  are  formed  simply  to  the  degree  to  which  the  media 
becomes  saturated  with  them,  not  because  they  **  paralyze  "  or  injure 
the  ferment.  For  upon  the  removal  of  these  products  by  dialysis, 
and  the  addition  of  a  fresh  quantity  of  albumen,  or  by  the  addition 
of  a  fresh  volume  of  the  acidulated  water  and  the  addition  of  albu- 
men, the  ferment  will  exhibit  its  digestive  action ;  and  repeatedly, 
to  such  an  extent  that  we  do  not  really  know  the  limits  of  its  action 
— the  life  of  the  enzyme. 
