414  Insecticidal  Value  of  Larkspur  Seed.  {As™pteXerPi9iT' 
THE  INSECTICIDAL  VALUE  OF  FLUIDEXTRACT  OF 
LARKSPUR  SEED.* 
By  J.  B.  Williams. 
An  examination  of  several  samples  of  fluidextract  of  larkspur 
seed  on  the  market  at  the  present  time  showed  a  very  marked  dif- 
ference in  their  physical,  chemical,  and  insecticidal  properties.  The 
samples  examined  varied  in  color  from  a  dark  brown  to  a  very  light 
yellow ;  the  alcoholic  content  from  40  per  cent,  to  80  per  cent.,  the 
fixed  oil  content  from  less  than  0.2  per  cent,  to  nearly  20  per  cent., 
the  alkaloidal  strength  from  0.43  per  cent,  to  over  1  per  cent.,  while 
the  insecticidal  value  varied  500  per  cent.  (1  to  5). 
With  the  object  in  view  of  determining  if  possible  the  constit- 
uent of  larkspur  seed  to  which  it  owes  its  insecticidal  properties, 
and  the  best  means  of  extracting  the  same,  a  number  of  fluidextracts 
were  prepared,  using  various  menstrua.  The  resulting  fluidextracts 
were  assayed  for  alkaloidal  content  and  also  for  fixed  oil,  and  their 
insecticidal  value  was  determined  by  tests  on  living  insects  (bedbugs). 
The  seed  used  was  that  of  DeipJiiniuni  ajacis,  L.,  and  was  ground  to 
a  No.  30  powder.  The  methods  of  extraction  were  as  follows  : 
•No.  1. — Extracted  by  percolation  with  95  per  cent,  alcohol,  the 
strong  percolate  reserved  and  extraction  continued  until  the  drug  was 
practically  exhausted ;  the  weak  percolate  evaporated  to  a  soft  extract 
and  dissolved  in  the  reserved  portion,  and  sufficient  95  per  cent, 
alcohol  added  to  make  1  c.c.  for  each  gramme  of  drug  used.  Upon 
standing  this  fluid  separated  into  two  well-defined  layers,  the  upper 
oily  layer  equalling  about  45  per  cent,  and  the  lower  layer  about  55 
per  cent,  of  the  whole.  These  were  separated  and  each  made  up  to 
the  original  volume  with  95  per  cent,  alcohol  and,  for  purposes  of 
identification,  marked  i-A  for  the  upper  and  i-B  for  the  lower 
layer. 
No.  2. — Extracted  by  percolation  in  usual  manner  with  dilute 
alcohol. 
No.  3. — Extracted  with  30  per  cent,  alcohol. 
No.  4. — Extracted  with  petroleum  benzine,  the  benzine  removed 
*  Presented  at  the  meeting  of  the  American  Chemical  Society  at  Rochester, 
N.  Y.,  September,  1913. 
