Am.  Jour.  Pharm.j        Rennet  Ferment  in  Withania  Coagulans.  163' 
March,  1884. 
coloring-matter  is  scarcely  soluble  in  either  ether  or  alcohol,  so  that  no 
advantage  is  gained  by  a  preliminary  treatment  with  these  before 
extraction  with  the  salt  solution.  I  have  also  endeavored  to  get  rid  of 
the  color  by  treating  the  seeds  as  rapidly  as  possible  with  successive 
quantities  of  water  before  making  the  final  extract.  By  using  a  cen- 
trifugal machine  I  was  able  to  wash  the  seeds  six  or  seven  times  with 
large  volumes  of  water  without  their  being  exposed  for  any  considera- 
ble time  to  the  action  of  the  water.  Each  portion  of  water  was  highly 
colored  and  the  seeds  were  thus  freed  from  adherent  coloring-matter. 
But,  apart  from  the  fact  that  some,  though  not  much,  ferment  is  thus 
lost,  no  special  advantage  is  obtained,  since  the  seeds  are  themselves 
colored,  and  even  after  prolonged  treatment  with  water  the  final  extract 
is  always  of  a  dark  brown  color. 
In  order  to  obviate  the  disadvantages  of  this  coloring  matter,  if 
disadvantage  it  is,  I  have  found  it  best  to  prepare  very  concentrated 
active  extracts  of  the  purified  seeds,  so  that  it  should  only  be  necessary 
to  add  a  very  small  quantity  of  the  extract  in  order  to  coagulate  the 
milk  and  obtain  a  colorless  curd.  This  I  have  done  by  grinding  the 
dry  seeds  very  finely  in  a  mill  and  extracting  them  for  twenty-four 
hours  with  such  a  volume  of  5  per  cent,  sodic  chlordide  solution  that 
the  mass  is  still  fluid  after  the  absorption  of  water  by  the  fragments 
of  the  seeds  as  they  swell  up.  From  this  mass  the  fluid  part  may  be 
readily  separated  by  using  a  centrifugal  machine  (such  as  is  used  in 
sugar  refining),  and  it  can  then  be  easily  filtered  through  filter-paper ; 
without  the  centrifugal  machine  the  separation  of  the  fluid  from  the 
residue  of  the  seeds  is  tedious  and  imperfect,  40  grams  of  the  seeds 
treated  as  above  with  150  cubic  centims.  of  5  per  cent,  sodic  chloride 
solution  gave  an  extract  of  which  0*25  cubic  centim.  clotted  20  cubic 
centims.  of  milk  in  twTenty  five  minutes,  and  0*1  cubic  centim.  clotted 
a  similar  portion  of  milk  in  one  hour.  When  added  in  these  propor- 
tions the  curd  formed  is  quite  white.  The  presence  of  the  coloring- 
matter  is  however,  perhaps  on  the  whole  unimportant,  since  even  if  a 
larger  quantity  of  the  ferment  extract  is  added  in  order  to  obtain  a 
very  rapid  coagulation  the  coloring  matter  is  obtained  chiefly  in  the 
whey,  the  curd  being  white.1 
1  It  is  extremely  probable  that  some  stage  in  the  growth  or  ripening  of 
the  seeds  of  Withania  might  be  found  at  which  the  development  of  color- 
ing-matter is  slight,  while  at  the  same  time  the  ferment  is  present  in  con- 
siderable quantity. 
