Am. Jour.  Pharm. 
July,  1897. 
Insect  Powders  of  Commerce. 
363 
folium,  it  is  very  important  to  mention  the  fact  that  chlorophyll,  in 
its  green  unchanged  form,  is  not  found  in  selected  dried,  closed 
insect  flowers,  as  this  fact  has  an  important  bearing  on  one  (and  I 
think  the  most  prevalent)  form  of  sophistication  to  be  found  in  the 
present  insect  powders  of  commerce.  I  cannot  fully  explain  why  it 
is  that  insect  powder  from  half-open,  and  from  flowers  that  are  fully 
developed,  should  show  a  certain  amount  of  chlorophyll  coloring  in 
the  ether  extract,  but  it  may  possibly  be  that  less  care  is  taken  in 
collection  of  these  than  is  the  case  with  the  more  valuable  closed 
flowers.  But  whatever  may  be  the  cause,  the  fact  remains  that 
insect  powder  ground  from  selected  closed  flowers  is  sensibly  free 
from  chlorophyll,  whereas  traces  of  it  (less  than  0-5  per  cent.)  will  be 
found  in  powders  prepared  from  mixed  and  half-open  flowers,  and 
in  the  foreign-ground  insect  powders  it  often  amounts  to  from  50  to 
80  per  cent,  of  the  total  ether  extract.  Samples  have  been  recently 
examined  by  me  yielding  6  per  cent,  of  ether  extract,  of  which 
more  than  two-thirds  was  owing  to  chlorophyll.  It  will  therefore 
be  seen  that  any  estimate  of  the  value  of  insect  powder  based  upon 
the  percentage  of  ether  extract  would  be  quite  fallacious  unless  the 
chlorophyll  be  also  determined  and  deducted  from  the  total. 
Microscopical  examination  is  useful  in  distinguishing  the  grosser 
forms  of  admixture,  such  as  powdered  quassia  and  the  woody  tissue 
of  the  leaves  and  stems  of  the  plant,  but  this  latter  form  of  sophisti- 
cation can  be  determined  by  the  method  given  further  on.  [For 
full  particulars  of  the  microscopical  appearance  of  true  insect 
flowers,  the  reader  is  referred  to  the  paper  by  Mr.  William  Kirkby, 
F.R.M.S.  (Proc.  Brit.  Pharm.  Con/.,  1888).] 
Adulterants. — In  using  the  term  adulterants  as  applied  to  our  sub- 
ject, it  is  intended  to  imply  the  presence  in  insect  powder  of  any- 
thing but  the  flowers  of  C.  cinerariaefolium.  Adulterators  of  insect 
powder  have  for  their  first  object  the  cheapening  of  the  article  sold, 
and  occasionally  they  have  a  second  object,  i.  e.,  to  improve  its  color. 
The  first  object  has  been  achieved  in  the  past  by  the  addition  of 
powder  of  quassia,  aloes,  senna  and  Hungarian  daisy,  and  the  artistic, 
eye  of  the  ignorant  buyer  has  been  satisfied  by  the  addition  of  the 
powder  of  fustic,  turmeric  and  chrome-yellow.  The  presence  of 
quassia,  fustic  and  turmeric  may  be  detected  by  the  aid  of  the 
microscope,  and  chrome-yellow  (salt  of  lead)  chemically.  The  pres- 
ence of  the  powder  of  Hungarian  daisy  is   more  difficult  to  detect 
