58 
Animal  Digestive  Ferments. 
f  Am.  Jour.  Pharm. 
1    February,  1902. 
saccharifying  power  of  the  pancreas,  although  in  1833  Eberle  found 
his  artificial  pancreatic  juice  to  convert  starch  into  sugar.  French 
gives  the  credit  to  Professor  Valentin,  of  Bera,  although  Gamgee 
in  his  history  now  objects  to  this. 
Bernard,  in  1845,  states  that  the  whole  function  of  the  pancreas 
;is  its  power  to  emulsify  fat  ;  this  function  was  first  noted  by  Eberle. 
Frerich,  in  1846,  reviews  the  whole  subject  of  digestive  ferments, 
stating  that  the  pancreatic  juice  changes  starch  to  sugar,  decom- 
poses bile  into  insoluble  substances  for  excretion,  and,  with  the 
assistance  of  the  bile,  emulsifies  fats.  He  argues  in  favor  of  an 
analogy  between  digestion  and  fermentation,  combating^the  pepsin- 
hydrochloric  acid  and  "contact"  theories;  assails  Bernard  for 
assuming  that  all  of  the  various  phenomena  of  digestion  are  pro- 
duced by  one  and  the  same  ferment,  insisting  upon  the  existence  of 
independent  ferments  possessing  specific  powers,  grouping  them  as 
digestive  ferments. 
In  1849  Bernard  reports  success  in  establishing  pancreatic  fistulae 
in  dogs,  thereby  opening  up  the  field  for  accurate  investigations  of 
this  gland.    He  failed  to  note  its  proteolytic  function. 
Bidder  and  Schmidt,  in  1852,  contribute  a  paper  on  the  digestive 
fluids  of  dogs  and  cats,  giving  an  analysis  of  gastric  and  pancreatic 
juices.  With  the  latter  they  fail  to  obtain  proteolytic  action  on  coagu- 
lated egg  albumen,  but  obtain  marked  action  on  starch.  Their 
remarks  on  pepsin  contain  nothing  noteworthy. 
Although  there  is  some  dispute  whether  Eberle  or  Purkinji  and 
Pappenheim  should  be  given  the  priority  of  discovering  the  proteo- 
lytic power  of  the  pancreas,  Corvisart,  in  1857,  removed  all  doubt 
concerning  the  existence  of  the  proteolytic  power  by  careful  sys- 
tematic investigation.  He  pointed  out  that  the  activity  of  the  juice 
varied  with  the  time  elapsed  since  feeding,  and  believed  the  failure 
of  others  to  note  this  function  of  the  gland  due  to  killing  the  animal 
at  the  most  unfavorable  period  of  digestion,  the  most  active  being 
between  the  sixth  and  ninth  hour  after  a  full  meal. 
In  1858  Dr.  Lionel  Beale  published  a  method  of  preparing  pepsin 
by  scraping  the  mucous  membrane  of  the  stomach  and  drying  the 
viscid  fluid  so  obtained  on  glass  at  a  low  temperature.  He  and 
Corvisart  appear  the  first  to  suggest  the  use  of  "  pepsin  "  in  medi- 
cine. 
Meissner,  in  1859  and  i860,  made  an  exhaustive  study  of  both 
