^pfembei^S.'  }  American  Pharmaceutical  Association. 
435 
observed  melting-points  of  the  soluble  portions.  The  resin  of 
P.  peltatum  lost  3.215  per  cent,  on  drying  at  ioo°  C,  and  that  of 
P.  emodi  3.25  per  cent. 
Solvent. 
P. 
peltatum  Resin. 
P.  EMODI 
Resin 
99-5  % 
98.01% 
2.41% 
1-94% 
Carbon  tetrachloride  
8.12% 
melting-point 
114- 
133 
6.85  %,  melting 
point 
168 
12.65% 
melting-point 
40- 
63 
6.95  %,  melting 
point 
40-46 
25.57  % 
melting-point 
80- 
129 
23.60  %,  melting 
point 
80-118 
32.40  % 
melting-point 
70- 
103 
18.50  %,  melting 
point 
75-103 
70.60  % 
melting-point 
86- 
1 20 
76.90  %,  melting- 
point 
92-120 
Ether  
89.00  % 
83.72% 
The  melting-points  in  all  of  the  above  simply  indicate  that  each 
solvent  extracts  a  mixture  of  bodies,  and  that  a  separation  of  the 
constituents  by  this  method  is  impracticable.  Petroleum  ether  is 
said  to  extract  mainly  fat,  and  benzol  appears  to  extract  the  color- 
ing matters  more  quickly  than  the  other  partial  solvents.  Carbon 
disulphide  solution  contains  a  considerable  proportion  of  resin. 
It  is  apparent  that  by  the  best  methods  of  estimation  at  present 
known  the  resin  from  the  Indian  drug  contains  about  twice  as  much 
podophyllotoxin  as  that  from  the  American  rhizome. 
Some  pure  podophyllotoxin  was  then  separated  from  each  resin 
for  comparison.  On  dissolving  the  resin  in  chloroform  and  pouring 
the  chloroformic  solution  into  twenty  times  its  volume  of  petroleum 
ether  (which  was  the  method  proposed  by  Kremel  and  used  by 
Umney  as  the  basis  of  his  judgment  concerning  the  relative  value 
of  the  two  resins),  it  was  noticed  that  the  resins  are  precipitated 
more  easily  and  completely  than  the  podophyllotoxin  by  the  petro- 
leum ether.  The  greater  portions  of  the  resins  and  coloring  matter 
were  separated  by  fractional  precipitation  in  this  way,  the  first  pre- 
cipitate being  rejected  and  the  second  reprecipitated  several  times. 
Finally  a  pure  product  was  obtained  by  fractional  crystallization 
from  benzol  solutions.  In  this  way  about  3  Gm.  of  pure  white  podo- 
phyllotoxin was  obtained  from  100  Gm.  of  resin  of  P.  peltatum,  and 
about  16  Gm.  having  a  faint  green  tint  from  the  resin  of  P.  emodi. 
The  first  melted  sharply  at  1170  C.  and  the  second  at  117.50  C., 
showing  that  both  are  practically  pure  products.  There  is  a  large 
loss  in  purifying,  yet  the  greater  yield  obtained  from  the  Indian 
resin  is  confirmatory  of  the  conclusions  reached  by  the  assay 
processes. 
