508 
Soluble  and  Insoluble  Pepsin. 
Am.  Jour.  Pharm. 
Oct.,  1882. 
SOLUBLE  AND  INSOLUBLE  MODIFICATIONS  OF  THE 
GASTRIC  FERMENT. 
By  a.  Gautier. 
Solution  of  pepsin  from  the  slieep,  filtered  twice  through  paper,  and 
then  throngh  biscuit  porcelain,  still  retains  the  property  of  rapidly  dis- 
solving fibrin,  and  converting  it  completely  into  peptone.  It  has,  how- 
ever, only  about  half  the  digestive  power  of  the  unfiltered  liquid. 
This  soluble  pepsin  has  also  the  property  of  fixing  itself  on  fibrin  in 
an  insoluble  form,  as  recently  observed  by  Wurtz.  The  portion  left 
on  the  filter,  after  prolonged  washing,  consists  mainly  of  rounded  or 
ovoid  refractive  corpuscles,  about  one-tenth  or  one-twelfth  the  diameter 
of  the  globules  of  beer  yeast.  They  have  a  somewhat  slow,  non- 
brownian  motion,  and  are  frequently  associated  in  pairs,  in  which  con- 
dition they  appear  to  be  more  mobile.  They  are  accompanied  by 
numerous  agglomerations  of  brilliant  immobile  corpuscles,  together 
with  crystals  of  ammonium  magnesium  phosphate,  fatty  globules,  and 
liere  and  there  very  small  bacteria :  0*086  gram  of  the  dry  insoluble 
matter  was  obtained  from  4  grams  of  pepsin.  This  insoluble  portion, 
in  presence  of  dilute  hydrochloric  acid,  has  a  power  of  dissolving  fibrin 
six  times  greater  than  that  of  the  unfiltered  pepsin,  but  the  process  of 
digestion  is  not  complete,  even  after  a  long  time,  the  fibrin  being  con- 
verted into  intermediate  products,  which  are  precipitated  by  nitric 
acid.  The  insoluble  particles  are  probably  protoplasmic  granules  from 
the  peptogenic  cells.  The  insoluble  granules  obtained  from  pepsin  are 
gradually  but  slowly  converted  into  the  soluble  modification  in  pres- 
ence of  pure  water.  This  affords  proof  of  Bechamp's  supposition 
("Compt.  rend."  94,  p.  582)  that  pepsin  is  a  product  of  these  gastric  mi- 
crozymas,  as  he  terms  the  insoluble  granules.  The  author  is,  however, 
unable  to  agree  with  Bechamp  that  these  granules  are  living  organisms 
w^hich  have  the  power  of  secreting  pepsin.  He  regards  them  as  a 
purely  chemical  ferment,  without  organization  and  without  life,  and 
bases  this  conclusion  on  the  following  facts.  The  granules  show  no 
signs  of  organized  structure  under  the  highest  magnifying  power;  they 
do  not  propagate  even  under  most  favorable  conditions;  they  digest 
albuminoids  in  presence  of  poisons  which  completely  check  the  activity 
of  organized  ferments,  especially  such  as  are  of  the  nature  of  vibrioles, 
and  they  act  only  in  presence  of  free  acids,  whereas  bacteria  and  their 
germs  require  a  neutral  or  alkaline  medium. 
