ON  A  TEST  FOR  THE  RESIN  OF  CANNABIS  INDICA.  23 
It  is  questionable  whether  the  excitant  and  stimulant  action  of 
the  salt  in  its  therapeutic  uses  be  not  due,  in  part  at  least,  to 
the  small  proportion  of  free  potassa  always  present  or  formed 
in  the  solution. 
Brooklyn,  December  16,  1864. 
ON  A  TEST  FOR  THE  RESIN  OF  CANNABIS  INDICA. 
By  William  Procter,  Jr. 
Having  accepted  the  question,  "  Is  there  a  reliable  test  for  the 
active  resin  of  Cannabis  sativa  of  the  East  Indies,  whereby  the 
genuineness  of  4  Extract  of  Indian  Hemp '  may  be  satisfactorily 
and  easily  ascertained  by  the  pharmaceutist  ?"  the  following  paper 
is  offered  as  a  reply. 
It  need  hardly  be  said  that  extract  of  Indian  Hemp  is  a  valu- 
able medicine  in  the  opinion  of  many  practitioners,  when  pre- 
pared from  hemp  tops  that  have  had  their  virtues  developed  by 
growth  in  a  favorable  climate  and  soil.  In  East  Indian  com- 
merce there  are  three  substances  derived  from  the  hemp  plant, 
viz. ;  gunjah)  consisting  of  the  flowers  and  incipient  fruit,  with 
the  smaller  branches ;  hang  made  up  of  the  leaves  and  capsules 
without  the  stalks ;  and  churrus,  the  resinous  matter  secreted  by 
the  hemp  plant  under  favorable  circumstances.  These  have  been 
long  known  in  the  East,  but  the  form  in  which  it  has  been  chiefly 
employed  by  European  and  American  practitioners,  is  the  alco- 
holic extract  of  gunjah.  The  variableness  in  the  medicinal 
power  of  this  extract  has  been  the  cause  of  much  disappointment 
to  physicians ;  for  whilst  some  samples  prove  effective  in  half- 
grain  doses,  ten  or  even  twenty  grains  of  other  specimens  have 
failed  to  produce  its  peculiar  influence  on  the  nervous  system. 
The  extract  of  commerce  varies  in  consistence  and  color.  Its 
green  hue  is  sometimes  much  darker  than  at  others,  and  its  odor 
is  equally  variable  in  strength.  -Although  professedly  an  alco- 
holic extract,  much  of  it  is  but  partially  soluble  in  alcohol  of  90 
per  cent.  In  a  sample  of  extract,  that  had  been  imported  seve- 
ral years  ago  from  Mr.  Squire,  of  London,  in  bulk,  as  much  as 
40  per  cent,  of  the  preparation  was  insoluble  in  stronger  alcohol. 
The  undissolved  portion  was  brown,  and  readily  soluble  in  water. 
