Am.  Jour.  Pbarm. 
April,  1897. 
Parthenium  Hysterophorous. 
177 
The  following  figures  were  obtained  : 
Month  of 
Collection. 
Weight  in 
Grammes. 
Weight  in 
Grammes. 
Percentage 
April 
May 
June 
July 
August  . 
September 
Fresh . 
I34'66 
737" 
552-8 
885-9 
680-4 
538-65 
Dried. 
3°'3 
150-5 
I2y6 
177-2 
106-3 
i55"9 
of  Loss. 
77-49 
79"5 
76-91 
79*99 
84-37 
7i'5o 
In  each  case  the  sample  was  dried  by  hanging  in  a  room  ac- 
cessible to  draughts  of  air  for  six  to  eight  weeks.  While,  of 
course,  owing  to  the  complex  structure  of  the  drug  and  the  vary- 
ing proportion  of  cellular  and  ligneous  tissue,  such  data  cannot 
be  exact,  it  is,  nevertheless,  useful  in  establishing  the  fact  that 
the  amount  of  water  in  the  fresh  herb  is  somewhere  between  70  and 
80  per  cent. 
The  average  percentage  of  active  principle  was  the  next  problem, 
and  its  extraction  was  performed  by  exhausting  the  drug  with 
diluted  alcohol ;  distilling  off  the  alcohol ;  filtering  the  aqueous 
residue ;  washing  the  filter  with  water  until  the  filtrate  was  tasteless, 
and  extracting  the  aqueous  liquid  by  agitation  with  chloroform.  In 
this  way  a  slightly  impure  yellow  amorphous  mass  was  obtained, 
and  the  yield  was  as  follows  : 
Per  Cent. 
25  grammes  air-dried  drug,  collected  in  April,       yielded  .  .  .  0-31 
100       "         "     "        "  "        "  May,  w      ...  0*84 
100       "         "     "        "  "        "  June,  "      ...  1-03 
100       "         "     "  f        "        "July,  "      ...  1*13 
75       "         "     "        "  "        "  August,  -■      ...  o'66 
100       "         "     "        "  "        "  September,     "     ...  0-53 
It  will  be  seen  that  the  quantity  of  active  principle  in  the  plant 
gradually  increases  to  the  maximum  in  July,  when  it  diminishes 
with  the  length  of  days  until  in  October  the  plant  is  almost  free 
from  bitterness. 
The  process  of  extraction  described  above  was  not  satisfactory, 
as  the  product  was  invariably  contaminated  with  coloring  matter  ; 
so  other  methods  were  tried.  That  used  in  the  preparation  of 
salicin — treatment  of  a  decoction  with  lead  oxide,  removal  of  excess 
with  sulphuric  acid  and  neutralization  of  free  acid  with  barium  sul- 
phide— did  not  prove  satisfactory,  as  the  lead  oxide  failed  to  remove 
all  the  coloring  matter. 
