232  Remarks  on  Resin  of  Podophyllum.  {^gft^KP 
yellow  powder,  which  was  at  first  supposed  to  be  the  native  berberina 
salt,  but  was  found  to  be  entirely  free  from  this  alkaloid.  On  con- 
tinuing the  treatment  of  the  undissolved  residue  with  boiling  water, 
the  filtrate,  on  cooling,  continued  to  deposit  a  powder,  at  first  of  the 
same  color  as  that  previously  obtained  ;  but  subsequent  portions  of 
the  clear  filtrate  separated  a  much  darker  colored  powder.  A  com- 
paratively small  amount  only  of  the  officinal  resin  appeared  to  be  in- 
soluble in  the  hot  water,  but  its  percentage  was  not  ascertained. 
This  observation  was  conclusive  proof  that  the  term  resin  is  a  mis- 
nomer for  this  officinal  preparation,  although  it  is  the  best  descriptive 
|term  that,  in  our  present  state  of  knowledge,  can  be  applied.  But 
the  behaviour  to  water,  as  indicated  above,  appears  also  to  point  to 
a  method  whereby  the  constituents  of  this  so-called  resin  may  be 
separated  from  each  other,  or  their  complete  separation  be  verified. 
To  the  above  facts  I  have  since  called  attention  in  my  lectures,  en- 
deavoring to  induce  some  one  having  sufficient  time  at  command  to 
investigate  the  true  chemical  nature  of  this  preparation.  It  is  to  be 
regretted  that  Mr.  Power's  time  did  not  permit  him  to  pursue  the 
subject  further. 
The  complete  solubility  of  the  active  portion  of  resin  of  podophyl- 
I  lum  in  water  being  conclusively  proven,  it  may  perhaps  be  taken  ad- 
vantage of  in  such  cases  where  it  is  to  be  given  in  very  small  doses, 
and  in  a  pleasant  liquid  form.  But  the  precise  extent  of  this  solo^ 
bility  in  water  of  different  temperatures  requires  to  be  ascertained. 
In  a  paper  by  Mr.  C.  Bullock  (see  American  Journal  of  Pharmacy y 
1862,  p.  114,)  it  is  stated,  upon  the  authority  of  the  "Journal  of 
Materia  Medica,"  that  the  resin  soluble  in  ether  varies  considerably 
with  the  season  in  which  the  officinal  rhizome  is  collected  ;  careful 
assays  of  the  latter  as  collected  monthly,  (in  the  Middle  States)  from 
April  to  October,  can  alone  determine  the  extent  of  this  variation, 
and  may  then,  perhaps,  also  clear  up  the  contradictory  statements  re- 
lating to  the  activity  of  the  portion  insoluble  in  ether;  of  this  solvent 
not  only  the  commercial  name  (washed  or  concentrated  ether)  should 
be  given,  but  its  correct  specific  gravity  at  60°  F.  should  always  be 
ascertained.  Those  interested  in  this  investigation  are  referred  also 
to  a  note  by  Prof.  Procter,  in  the  American  Journal  of  Pharmacy y 
1860,  p.  210. 
