46 
Essence  of  Senna  Pods. 
Am.  Jour.  Pharm. 
Jan.,  1890. 
two  and  one-half  per  cent,  of  cathartin  as  compared  with  two  per  cent, 
only  in  the  leaves.  But  he  does  not  say  if  this  substance  was  purified 
further  than  by  precipitation  with  alcohol ;  if  not,  it  may  contain 
some  little  mucilaginous  and  albuminous  matter.  Two  samples  of 
pods  examined  by  myself  contained  0'72  and  0'8  per  cent,  of  pure 
cathartic  acid,  obtained  by  precipitating  a  fluid  extract  with  an  equal 
bulk  of  absolute  alcohol ;  the  liquid  filtered  from  the  precipitated  mu- 
cilage and  salts  was  mixed  with  more  absolute  alcohol,  as  long  as 
a  precipitate  was  produced.  This  precipitate  was  washed  with  alcohol, 
dissolved  in  a  little  water,  freed  from  albumen  by  a  few  drops  of 
hydrochloric  acid,  and  the  filtrate  completely  precipitated  by  the  addi- 
tion of  more  hydrochloric  acid  ;  the  impure  cathartic  acid  thus  obtained 
was  purified  by  dissolving  in  60  per  cent,  alcohol  and  precipitating  by 
ether.  My  object  has  not  been  to  make  an  exhaustive  inquiry  into 
the  relative  merits  of  senna  leaves  and  pods,  but  to  propound  on  a 
knowledge  of  the  foregoing  what  appears  to  me  a  rational  formula  for 
the  fluid  extract  or  essence. 
Although  hydraulic  pressure  is  undoubtedly  the  best  for  the  pur- 
pose, a  good  screw-press  answers  fairly  well,  and  the  "  Enterprise " 
press  is  still  better.  Operating  then  on  1  lb.  of  pods,  the  formula  I 
would  suggest  is  as  follows : 
Senna  pods,  slighly  bruised  .  1  lb. 
Rectified  spirit  5  oz. 
Distilled  water  12  oz. 
Press  the  pods  well  down  in  the  containing  vessel  and  pour  on  the 
mixed  spirit  and  water;  in  twenty-four  hours  reverse  the  position  of 
the  pods  and  allow  to  stand  a  further  period  of  four  to  five  hours, 
subject  to  strong  pressure;  set  aside  the  liquid  in  a  bottle,  break  up 
the  marc,  and  pour  on  this  the  following  previously  mixed: — 
Glycerin   1  oz. 
Liquid  ammonia  20  minims. 
Distilled  water  19  oz. 
Allow  to  stand  four  hours,  press  strongly,  strain  and  evaporate  the 
liquid  so  obtained,  until  when  well  mixed  with  the  first  liquor  and 
filtered  16  fluidounces  will  be  produced.  The  addition  of  one  drop 
each  of  oil  of  caraway  and  essence  oil  of  almonds,  with  two  drops  of 
essence  of  lemon,  makes  it  really  palatable.  The  medium  adult  dose 
is  one  fluidrachm. 
