ArebruYryTi902m'}  Animal  Digestive  Ferments.  65 
the  ordinary  conditions  of  manufacture,  without  decomposition,  until 
reduced  to  dryness. 
It  is  to  be  noted  in  this  connection  that  the  sodium  chloride  and 
the  other  salts  suggested  by  SchefTer  threw  out  of  solution  a  very 
large  proportion  of  the  soluble  proteid  bodies  formed  in  the  macer- 
ation of  the  stomach,  or  the  stomach  membrane,  in  the  diluted 
hydrochloric  acid  at  ordinary  temperatures  ;  the  viscid  solution  thus 
formed  containing  the  proteids  very  largely  in  the  form  of  albumose, 
this  giving  an  exceedingly  copious,  light,  flocculent  precipitate, 
which  has  the  advantageous  property  of  rising  to  the  surface  and 
of  carrying  the  ferment  embedded,  so  to  speak,  with  the  proteids  in 
which  it  is  associated. 
By  re-solution,  clarification  and  re-precipitation,  the  product 
obtained  could  be  purified  to  a  considerable  degree  from  the  pre- 
cipitant and  associated  proteids  and  salts  of  the  gastric  infusion,  and 
a  pepsin  thus  of  great  activity  resulted.  This  Scheffer's  "  purified 
pepsin,"  however,  did  not  come  into  general  use  in  medicine,  and 
was  especially  offered  as  a  means  of  preparing  saccharated. 
SchefTer  himself,  although,  as  he  remarked,  confining  himself 
specifically  to  the  production  of  a  pepsin,  leaving  its  virtue  to  be 
established  by  physicians,  nevertheless  expressed  the  opinion  that 
the  "  purified  "  (undiluted)  pepsin  might  produce  undesirable  results. 
He  considered  the  milk  sugar  desirable,  therefore,  in  addition  to  its 
specific  utility,  as  a  means  of  reducing  the  pepsin  to  a  pulverulent 
form,  overcoming  the  obstacle  inherent  in  the  extremely  tough  and 
insoluble  nature  of  the  precipitated  pepsin  when  reduced  to  dryness 
without  some  suitable  absorbent. 
Saccharated  pepsin  by  the  SchefTer  process  soon  became  very 
generally  manufactured  in  commerce,  but  its  very  advantages,  the 
facilities  with  which  the  raw  material  could  be  treated  and  the 
product  obtained,  may  account  for  the  appearance  in  commerce  of 
pepsin  which  obviously  could  not  have  been  produced  by  any  means 
in  accordance  with  Scheffer's  methods,  namely,  the  clarification  of 
the  acidulated  solution,  assay  of  the  precipitated  pepsin  and  incor- 
poration of  the  diluent  milk  sugar  to  a  definite  standard  of  digestion 
test.  Much  saccharated  pepsin  of  commerce  was  greatly  deficient 
and  feeble  in  action,  so  much  so  as  to  be  of  trifling  value. 
About  ten  years  subsequent  to  the  introduction  of  Scheffer's  pro- 
cess there  appeared  a  method,  patented  by  Jensen,  based  upon  the 
