37° 
The  Resin  of  Podophyllum. 
<  Am.  Jour.  Pharm. 
\      Aug.,  1878. 
treatment  with  large  amounts  of  water.  The  acid  resin  was  then 
further  examined,  as  detailed  in  my  previous  paper,1  by  exhaustion  with 
ether,  and  treating  the  portion  soluble  therein  (which  should  contain 
the  protocatechuic  acid  if  present,  associated  with  resin)  with  boiling 
water.  The  final  product,  thus  obtained,  consisted  chiefly  of  amor- 
phous resin,  and  all  efforts  to  isolate  a  crystalline  compound  therefrom, 
which  would  admit  of  a  more  minute  examination,  were  unsuccessful. 
Although  the  peculiar  character  of  the  resin  in  being  soluble  in  water 
presents  a  great  barrier  for  a  thorough  separation  and  examination  of 
its  constituents,  yet  from  the  amount  of  material  operated  upon,  and 
without  reliance  alone  upon  color  tests,  the  conclusion  must  be  drawn 
that  protocatechuic  acid  can  as  yet  only  be  obtained  as  a  decomposition 
product,  and  its  pre-existence  in  any  drug  must  still  remain  a  subject 
for  future  observation  and  discovery. 
In  the  course  of  this  investigation  notice  was  also  again  taken  of  the 
statement  of  Prof.  Mayer,  made  some  years  ago,2  in  regard  to  the  pres- 
ence of  a  colorless  alkaloid  in  the  rhizome,  which  may  be  precipitated 
by  lead  or  by  acids.  That  such  an  alkaloid  exists,  which  is  precipi- 
tated by  lead  salts,  seems  quite  improbable,  and  the  results  of  the 
present  investigation  have  also  failed  to  indicate  its  presence  ;  in  this 
respect  but  more  fully  confirming  the  results  of  my  previous  investiga- 
tion. That  the  alkaloid  Berberina  is  absent,  the  writer  believes  to 
have  quite  conclusively  proven,  and  may  be  supported  by  the  observa- 
tion of  Dr.  E.  R.  Squibb,  who  has  more  recently  subjected  a  liter  of 
the  filtered  liquid,  obtained  by  the  precipitation  of  the  resin,  to  the 
action  of  Mayer's  solution  of  mercurio-potassic  iodide,  but  with  nega- 
tive results.  It  may  not  be  inopportune,  in  this  connection,  to  call 
attention  to  the  fact  which,  if  generally  known,  is  not  always  considered, 
that  Mayer's  solution  of  mercurio-potassic  iodide,  as  well  as  other  com- 
monly-employed alkaloidal  reagents,  produce  precipitates  with  many 
other  substances  beside  alkaloids,  which  may  possibly  have  led  other 
investigators  astray  in  assuming  the  presence  of  an  alkaloid  in  the 
rhizome  of  podophyllum. 
u^In  view  of  this  fact,  we  can  only  be  justified  in  assuming  such 
reactions  as  simply  indicative,  but  by  no  means  as  furnishing  conclusive 
evidence  of  the  piesence  of  an  alkaloid  :  the  latter  only  to  be  estab- 
lished by  its  isolation  and  identification. 
1  Ibid. 
2  "Amer.  Jour.  Pharrr .,"  March,  1863,  vol.  >.xxv,  p.  98. 
