272 
REMARKS  ON  SENNA. 
The  liquid  thus  prepared  gave  us  the  means  of  obtaining  the 
compound  above  referred  to,  which  is  composed  of  a  mixture  of 
acids  and  other  substances  combined  with  lime,  and  free  lime. 
So  far  as  it  could  be  tested  by  its  action  on  the  human  frame,  it 
contained  all  the  active  principle  of  the  quantity  of  senna  from 
which  it  was  obtained.  To  prepare  it,  slacked  lime  was  made  into  a 
milk  and  added  to  the  spirituous  solution  of  the  extract  of  senna 
above  mentioned,  and  the  resulting  precipitate  on  being  collected 
by  filtration,  washed  with  strong  spirit,  and  dried  as  much  as 
possible  by  strong  pressure  between  folds  of  blotting-paper,  was 
found,  as  already  mentioned,  to  be  a  powerful  cathartic  in  the 
dose  of  4  or  5  grains. 
The  denial  of  the  solubility  of  the  active  principle  of  senna 
in  strong  spirit,  made  by  Mr.  Groves,  is  in  part  correct,  but 
cannot  apply  to  the  tincture  of  senna  of  the  British  Pharma- 
copoeia, as  the  spirituous  solution  which  gave  us  the  cathartic 
compound  waB,  at  the  least,  above  proof,  and  was  found  by  our- 
selves in  experiments  on  our  own  persons,  to  have  the  full 
strength  of  its  equivalent  of  senna  leaves. 
After  reaching  the  length  we  have  indicated  in  our  researches, 
we  were  reluctantly  compelled  to  desist  making  any  further 
attempts  to  arrive  at  the  end  we  had  in  view,  at  least  for  the 
time,  but  we  never  lost  the  hope  of  resuming  our  investigation 
under  more  favorable  circumstances.  In  an  investigation  of  the 
nature  of  the  present,  it  is  evident  that  wrong  steps  must  be 
checked  by  using  the  human  frame  as  a  medium  for  testing  the 
existence  of  a  cathartic  power  in  any  product.  In  consequence 
of  this  constantly  recurring  necessity  and  the  difiiculty  of  getting 
or  asking  another  person  to  submit  to  the  at  least  disagreeable 
ordeal,  we  were  led  to  dose  ourselves  to  such  an  extent  as  to 
bring  on,  in  one  of  us,  a  state  of  irritation  of  the  whole  mucous 
membrane  of  the  alimentary  canal,  extending  even  to  the  nos- 
trils, and  the  effects  of  which  have  not  disappeared  even  to  this 
day,  so  that  we  were  compelled  to  throw  aside  the  whole  inves- 
tigation, and  it  affords  us  much  pleasure  to  see  that  it  has  been 
taken  up  and  so  well  wrought  out  by  others. — Lond.  Pharm. 
Jour.,  Nov.,  1868. 
