Am.  Jour.  Pharm, 
June,  1887. 
Oil  of  Erigeron  and  Fireweed. 
307 
light  straw  color.  Upon  submitting  the  different  fractions  to  the  sp. 
gr.  and  polarizing  test,  the  following  results  were  obtained: 
ERIGERON. 
FIREWEED. 
No.  of 
Sp.  Gr. 
No.  of 
Sp.  Gr. 
fraction. 
at 15°C. 
Polarization. 
fraction. 
at  15°c. 
Polariz 
1  
•8598 
+10 
1  
•825 
—4 
2  
.  '860 
+13 
2  
  -82575 
—4 
3  
.  "862 
+15- 
3   
,  -8263 
—4 
4  
•862 
+15 
4  
•8268 
+1 
5  
.  -86225 
+15 
5 
  -827 
+5 
6  
,  -86225 
+15 
6  
....  -8273 
+4 
7  
.  -86225 
+15 
7  
....  -8275 
+4 
8  
.  -86225 
+15 
8  
  -8255 
—2 
9  
.  '86225 
+14-5 
9  
....  -8267 
0 
10   
.  -86225 
+14 
10  
  -8269 
+  1 
11  
.  '86275 
+12-5 
11  .... 
 6277 
+  1 
.  -8628 
+12 
12.. 
....  '8282 
+1 
13  
.  -8629 
+11 
+8 
13 
 8292 
+4 
14  
.  -8635 
14  
...  -831 
-1-5 
15  
.  -865 
0 
15  
,,  ,  -840 
+  2 
16  
•8672 
—3 
16  
....  -8568 
—9 
17  
•8684 
—35 
17  
....  -888 
—53 
18  
•9169 
—435 
18  
....  -919 
—85 
19.  3  lbs. 
.  -9388 
19 
  Resin 
20.  7  lbs. 
Resin 
20  
....  Resin 
It  will  be  noticed  that  the  same  phenomenon  occurs  in  the  fractional 
distillation  of  fireweed,  as  that  which  the  writer  discovered  in  oil  of 
peppermint,  recorded  in  the  Proceedings  of  the  American  Pharmaceut- 
ical Association  for  1885,  vol.  33,  page  579,  and  farther  mentioned  in 
vol.  34,  page  129),  viz :  That  after  several  fractions  have  been  re- 
covered in  which  the  sp.  gr.  constantly  increases,  there  is  a  point  found 
near  the  middle  of  the  distillate  (which  in  this  case  occurs  in  the  8th 
fraction)  where  the  direction  is  changed  to  a  decreasing  one.  In  the 
case  of  fireweed,  however,  there  was  but  one  fraction  which  showed  the 
decreasing  tendency,  although  fraction  9  as  well  was  lighter  than  frac- 
tion 7.  When  peppermint  is  divided  in  the  same  manner,  there  is  a 
greater  number  of  fractions  showing  this  phenomenon.  It  is  also  a 
remarkable  fact  that  the  polarizing  test  is  similarly  affected  at  this 
stage,  as  the  polarization  is  also  changed  from  +  4  to  —  2. 
None  of  the  fractions  of  erigeron  show  this  change  from  rising  to 
falling  gravity ;  but  it  will  be  noticed  that  there  is  a  tendency  in  that 
direction,  as  the  fractions  from  5  to  9  inclusive  remain  stationary  rather 
than  rising,  while  in  both  there  is  a  rapid  increase  in  the  last  fractions. 
