Am.  Jour.  Pharm. 
July.  1897. 
Insect  Powders  of  Commerce. 
361 
It  will  be  found  that  the  literature  of  the  subject  divides  itself 
into  the  following  sections  : 
(a)  Toxic  constituents. 
(b)  Microscopic  appearance. 
(c)  Adulterations. 
It  is  intended  to  keep  this  division  of  the  subject  so  far  as  may  be 
possible  and  convenient. 
So  far  back  as  1863,  Hanaman  Roch  (National  Dispensatory) 
attributed  the  insecticidal  value  of  the  powdered  flowers  of  Crys. 
caucasicum  to  a  volatile  oil.  Some  years  after,  in  the  seventies, 
Semenoff  appeared  to  be  practically  in  agreement  with  this  state- 
ment, but  treated  the  matter  more  broadly,  if  less  definitely,  by 
substituting  "  volatile  substance  "  for  the  more  definite,  if  less  ac- 
curate, "volatile  oil."  Immediately  after  in  (1876),  Jousset  de 
Bellesme  stated  that,  in  his  opinion,  the  active  toxic  principle  was  a 
crystalline  alkaloid.  In  1877  this  la<t  statement  was  corrected  by 
R.  Rother  (Druggists'  Circular  and  Chem.  Gazette),  in  a  paper  giv- 
ing the  results  of  a  very  systematic  and  practical  investigation  ;  the 
conclusions  at  which  this  writer  arrived  are  as  follows  :  There  is 
no  crystalline  alkaloid  ;  there  are  (a)  an  oleoresinous  greenish-yel- 
low acid,  u  persicein  ;"  (b)  another  acid  body,  "  persiretin,"  both 
inactive  ;  (c)  active  principle,  a  glucoside  converted  by  boiling  into 
"  persiretin  "  and  glucose.  These  constituents  are  all  soluble  in 
ether  alcohol,  benzine  and  petroleum  ether,  and  insoluble  in  chloro- 
form. With  the  latter  part  of  the  statement,  referring  to  the  solu- 
bility of  all  the  constituents  of  any  value  in  ether,  etc.,  I  can  cor- 
dially agree.  Very  shortly  after  the  appearance  of  this  article  by 
Rother,  a  notice  appeared  in  the  Bulletin  Soc.  Chitn.  by  G.  Dal  Sie, 
in  which  he  claims  that  the  active  toxic  principle  is  to  be  found  in 
a  volatile  acid  existing  in  the  flowers  in  a  free  state.  M.  Finzelberg 
[Pharm,  Centralhalle,  1880)  proved  that  a  concentrated  tincture  of 
the  flowers  had  definite  insecticidal  properties,  and  this  statement 
has  been  confirmed  by  my  own  experiments  on  flies.  O.  Tester 
[Pharm.  Journ.  [3],  XII,  359),  states  that  the  active  principle  is  a 
soft  resin.  At  the  British  Pharmaceutical  Conference,  1888,  a  paper 
was  read  by  William  Kirkby  on  the  microscopical  characteristics  of 
the  flowers  of  C.  caucasicum  and  C.  cinerariaefolium.  The  paper 
was  valuable  so  far  as  the  subject  was  treated,  but  it  was  less  com- 
plete than  the  author  intended,  inasmuch  as  sophistications  were  net 
