Am'M°aUyr;i903arru"}         Oils  of  Fireweed  and  Erigeron.  217 
surprising  that  very  little  genuine  oil  finds  its  way  into  the  channels 
of  trade.  This  condition,  however,  does  not  appear  to  worry  some 
oil  dealers,  for  they  boldly  fill  any  order  for  fireweed  oil  with  erigeron 
oil  and  label  it  fireweed  oil.  Such  fraudulent  transactions  cannot  be 
criticised  too  severely.  Let  everything  be  labelled  what  it  is.  In 
the  course  of  many  years  the  writers  have  met  with  but  two  con- 
signments that  complied  approximately  with  the  recognized  normal 
constants  of  oil  of  fireweed :  one,  a  limited  supply  at  a  high  price, 
from  a  large  grower  and  distiller,  and  the  other  from  a  small  distiller. 
In  1887  A.  M.  Todd1  made  a  careful  study  of  the  oil  known  to  be 
genuine,  and  a  few  years  later  F.  B.  Power2  went  over  the  oil  again. 
Their  results  were  as  follows: 
Source.  Specific  Gravity.  Opt.  Rot. 
Todd   0-845  —  0-855  —  4'  to  -f  40 
Power  0-838  at  18-5°  C.  —  20  to  +  2° 
The  two  oils  mentioned  above,  as  of  lairly  good  quality,  tested  as 
follows:  No.  1,  specific  gravity  0*8422,  opt.  rot.  -J-  i°  32',  soluble  in 
equal  volume  of  alcohol,  no  more ;  No.  2,  specific  gravity  0-8244, 
opt.  rot.  -}-  2°  I2r,  insoluble  in  alcohol. 
The  following  constants  are  typical  of  the  products  frequently 
supplied  for  oil  of  fireweed  :  Specific  gravity  0-859,  opt.  rot.  -f-  66°  48', 
soluble  in  an  equal  volume  of  alcohol.  The  above  data  indicate 
erigeron  oil,  which  has  been  found  to  possess  the  following  con- 
stants: Specific  gravity  0  850  to  0-870,  opt.  rot.  -f-  520,  soluble  in 
an  equal  volume  of  alcohol. 
We  desire  to  note  in  this  connection  that  either  the  commercial 
erigeron  oils  are  themselves  adulterated  or  they  vary  materially  in 
properties  (we  incline  toward  the  latter  view,  as  the  oil  readily  resini- 
fies),  as  the  following  results  show : 
Specific  Gravity.  Opt.  Rot. 
i   0-8904        +  +  280  48/ 
2  0-8629  +  84°  28' 
3  0*8963  +48° 
4  0-8604  +  830  427 
5  0-8551  +  720 
6  0-8549  4-  72° 
All  of  the  samples  examined  by  us  for  boiling-point  varied  from 
1720  to  1780  C,  uncorrected,  with  a  slight  residue. 
1  Am.  Jour.  Pharm.,  59,309. 
2  Pharm.  Rundschau^  5,  20J. 
