Am.  Jour.  Pharm. 
March,  1884. 
|        Rennet  Ferment  in  Withania  Coagulans.  161 
A  "  RENNET "  FERMENT  CONTAINED  IN  THE  SEEDS 
OF  WITHANIA  COAGULANS.1 
By  Sheridan  Lea,  M.A.,  Trinity  College,  Cambridge. 
The  Report  of  the  Royal  Gardens  at  Kew  for  1881  contains  abstracts 
of  correspondence  in  which  it  was  pointed  out  that,  in  order  to  intro- 
duce a  cheese-making  industry  in  India,  some  vegetable  substitute 
must  be  found  for  the  ordinary  animal  rennet,  since  cheese  made  with 
•the  latter  is  unsaleable  among  the  natives.  In  response  to  the  above 
a  Surgeon-Major  Aitchison  brought  to  the  notice  of  the  authorities  at 
Kew  that  the  fruit  of  Puneeria 2  coagulans,  a  shrub  common  in 
Afghanistan  and  Northern  India,  possesses  the  properties  of  coagulating 
milk;"  and  experiments  showed  that  an  aqueous  extract  of  the  seed- 
capsules  of  the  above  plant  does  somewhat  rapidly  coagulate  milk. 
I  was  recently  requested  to  make  some  eperiments  on  the  seeds  of 
Withania  to  determine  whether  they  contain  a  definite  ferment  with 
the  properties  of  ordinary  rennet,  and  the  applicability  of  such  a  fer- 
ment to  cheese-making  purposes. 
The  material  supplied  to  me  consisted  of  an  agglomerated  dry  mass 
of  seed-capsules  and  fragments  of  the  stalks  of  the  plant.  When 
crushed  in  a  mortar  the  whole  crumbled  down  into  a  coarse  powder, 
in  which  the  seeds  were  for  the  most  part  liberated  from  the  capsules. 
I  picked  out  the  larger  pieces  of  stalk,  sifted  out  the  finer  particles, 
chiefly  earth  and  fragments  of  the  capsules,  and  then  by  a  further 
sifting  I  separated  the  seeds  from  the  other  larger  particles.  The  seeds 
appeared  to  be  each  enveloped  in  a  coating  of  resinous  material,  pre- 
sumably the  dried  juice  of  the  capsules  in  which  they  had  ripened. 
Taking  equal  weights  of  the  seeds,  I  extracted  them  for  twenty-four 
hours  with  equal  volumes  of  (i)  water,  (ii)  5  per  cent,  sodic  chloride, 
(iii)  2  per  cent,  hydrochloric  acid,  (iv)  3  per  cent,  sodic  carbonate. 
Equal  volumes  of  each  of  the  above  were  added  in  an  acid,  alkaline, 
and  neutral  condition  to  equal  volumes  of  milk,  and  heated  in  a  water- 
bath  at  38°C.  The  milk  was  rapidly  coagulated  by  the  salt  and  sodic 
carbonate  extracts,  much  less  rapidly  by  the  other  two ;  of  the  four, 
the  salt  extract  was  far  the  most  rapid  in  its  action.    All  subsequent 
•   1  Communicated  by  Professor  M.  Foster,  Sec.  U.S.— From  the  "  Proceed- 
ings of  the  Royal  Society." 
2  The  genus  Puneeria  is  now  reduced  by  botanists  to  Withania. 
11 
