196  Commercial  Extract  of  Calabar  Bean.        { ^'^Apri^'iSs*'''"' 
If  it  were  found  that  extract  B,  contained  sufficient  alkaloid  for 
therapeutical  purposes,  the  compilers  of  our  Pharmacopceia  might  con- 
sider whether  they  should  not  allow  it  to  take  the  place  of  the  present 
€!Xtract ;  but  apart  from  this,  it  is  worthy  of  note  that  66  per  cent* 
alcohol  is  of  all  alcoholic  menstrua  the  best  suited  for  the  full  extrac- 
tion of  the  alkaloid,  while  those  of  a  lower  percentage  appear  to  be  in- 
admissible on  account  of  the  large  quantity  of  extractive  matter  dis- 
solved by  them. — Pharm.  Jour,  and  Trans.,  January  24, 1885,  p.  593. 
NOTE  OX  COMMERCIAL  EXTRACT  OF  CALABAR  BEAN.^ 
By  Peter  Mac  Ewen. 
Secretary  in  Scotland  to  the  Pharmaceutical  Society. 
It  is  evident  from  Mr.  Gibson's  communication  that  a  slight  varia- 
tion in  the  alcoholic  strength  of  the  menstruum  used  in  the  preparation 
of  this  extract  may  cause  considerable  ditference  in  its  character  and 
alkaloidal  strength,  and  some  diiference  may  also  arise  from  variation 
in  the  quality  of  the  drug.  Indeed,  we  may  surmise  indefinitely 
regarding  variation  in  the  strength  of  this  and  other  purely  galenical 
preparations.  We  do  not  expect,  under  our  present  system,  to  find 
them  uniform,  but  rather  live  in  the  hope  of  the  replacement  of  them 
by  standard ''  preparations  or  by  proximate  principles  when  these 
answer  therapeutical  requirements  and  can  be  economically  obtained. 
Fortunately,  in  the  case  of  Calabar  bean,  the  antagonism  between  its 
two  alkaloids,  physostigmine  (or  eserine)  and  calabarine,  has  lead  to  an 
extensive  use  of  the  former  alkaloid  in  preference  to  the  alcoholic 
extract,  which  has  repeatedly  proved  to  be  untrustworthy,  owdng  to 
the  conflicting  action  and  sometimes  preponderance  of  calabarine,  and 
also  owing  to  variations  in  alkaloidal  content.  But  the  extract  has 
not  fallen  into  disuse,  and  although  the  pharmacist  is  seldom  called 
upon  to  dispense  it,  the  cases  in  which  it  is  used  are  of  so  serious  a 
nature  that  it  is  most  important  that  it  should  be  of  good  quality 
and  that  diflerent  samples  should  at  least  approach  to  uniformity.  In 
order  to  ascertain  how  far  this  is  the  case  with  the  extracts  at  present 
supplied  to  the  pharmacist,  I  have  obtained  eight  samples  from  well- 
known  wholesale  houses  and  dispensing  establishments,  and  have  sub- 
1  Read  at  a  Meeting  of  the  North  British  Branch  of  the  Pharmaceutical 
Society,  January  14,  1885. 
