344  Strophanthus  Seed  of  Commerce.  {Amiuiy,'mi:rm' 
features  and  chemical  constituents.  The  difficulty  attending  the 
separation  of  genuine  or  official  seed  from  that  of  other  species  has 
recently  to  a  great  extent  been  overcome  by  a  very  careful  exami- 
nation of  the  seeds  of  commerce  by  Herr  C.  Hartwich  [Arch,  der 
Pharm.,  Bd.  231,  Heft  vi,  pp.  401-433). 
It  has  already  been  shown  by  Professor  T.  R.  Fraser  that  the 
seeds  investigated  by  him,  and  which  are  now  the  official  kind,  con- 
tain a  glucoside,  strophanthin,  which  gives  a  marked  green  reaction 
with  concentrated  sulphuric  acid  ( "  Trans.  Roy.  Soc.  Edinb.,"  vol. 
xxxv,  pt.  iv,  p.  ion),  and  this  fact  was  turned  to  account  by 
Hanausek  {Pharm.  Jonrn.  [3],  xvii,  p.  973)  as  a  means  of  ascer- 
taining the  genuine  character  of  the  seeds.  Blondel  (  "  Les  Stro- 
phantus du  Commerce,"  Paris,  1888,  p.  55)  examined  the  structure 
of  the  follicles  and  seeds  and  showed  that  several  of  the  commercial 
kinds  exhibited  histological  differences.  Herr  C.  Hartwich,  in  the 
paper  already  alluded  to,  has  carried  these  investigations  a  step 
further  by  making  a  careful  microchemical  examination  of  the  cell 
contents  of  the  seeds,  and  has  arrived  at  the  following  conclusions  : 
(1)  That  the  presence  of  strophanthin  can  be  detected  only  in  a 
few  of  the  commercial  varieties. 
(2)  That  several  kinds  contain  crystals  of  oxalate  of  calcium  in 
the  cotyledons,  and  that  the  presence  of  this  constituent  is,  as  a 
rule,  indicative  of  the  absence  of  strophanthin,  such  seeds  giving 
no  green  reaction  with  concentrated  sulphuric  acid  ;  the  only  excep- 
tion known  being  the  seed  from  the  Island  of  Los,  which  contains 
oxalate  of  calcium  as  well  as  a  trace  of  strophanthin.  The  absence 
of  the  calcium  oxalate  does  not,  however,  necessarily  indicate  the 
presence  of  strophanthin,  since  the  seeds  of  5.  Fischeri,  and  of  the 
glabrous  seed  from  Lagos,  contain  neither  raphides  nor  stro- 
phanthin. 
(3)  Starch  is  constantly  present  in  some  species,  but  not  in 
others ;  even  when  present  it  is  not  always  easily  detected,  unless 
the  seeds  be  first  treated  with  ether  to  remove  the  fatty  oil. 
The  presence  of  oxalate  of  calcium  and  of  starch,  therefore,  can 
be  used  only  as  confirmatory  evidence  where  necessary  to  discrimi- 
nate between  the  sorts  which  do  not  give  the  strophanthin  reaction. 
As  at  present,  however,  the  pharmacist  is  only  concerned  to  ascer- 
tain the  genuineness  of  the  seeds  containing  strophanthin,  the  sul- 
phuric acid  test  is,  for  practical  purposes,  quite  sufficient.    The  most 
