162 
Villosin  and  Villosic  Acid. 
/Am.  Jour.  Pharm. 
\      April,  1890. 
concentrated  H2S04  -f  2  drops  HN03,  a  deep  blood  red  color 
appears,  which  fades  in  not  less  than  8  hours,  but  disappears 
entirely  on  the  addition  of  water,  with  the  formation  of  a  precipi- 
tate. (2)  Treated  with  concentrated  H2S04  and  2  drops  H20,  aided 
with  a  little  heat,  a  blue  color  appears,  similar  to  the  one  obtained 
by  strychnine  with  H2S04  +  K2Cr2CL 
To  obtain  crystallized  villosin,  I  endeavored  to  improve  my  pre- 
vious method,  but  have  not  as  yet  succeeded.  A  weaker  menstruum 
than  alcohol,  sp.  gr.  0  820,  is  objectionable  as  the  extraction  is  not 
fully  accomplished.  The  lime  method  is  also  to  be  abandoned. 
Although  the  exhaustion  may  have  been  perfect  enough,  the  lime 
appears  to  decompose  the  villosin.  The  latter  is  precipitated  largely 
as  villosic  acid,  on  treating  the  last  filtrate  with  HC1. 
Now  regarding  the  glucoside  itself  I  have  already  shown  its 
nature  and  behavior  to  reagents,  and  although  there  is  no  doubt  to 
its  being  a  glucoside,  I  wish  to  mention  a  few  observations.  But 
before  so  doing  I  feel  obliged  to  correct  the  statement,  made  in  my 
thesis,  that  the  glucoside  itself  reduces  Fehling's  solution.  This  is 
an  error.  When  perfectly  pure,  villosin  does  not  reduce  Fehling, 
but  it  does  it  very  distinctly  after  having  been  boiled  with  dilute 
HQ. 
You  are  aware  that  the  washing  of  the  ferric  hydrate,  in  order  to 
remove  (NH4)2  S04  appears  to  be  an  essential  part  in  the  process, 
the  Fe2  (OH)6  being  employed  to  precipitate  the  tannin.  It  is  diffi- 
cult to  obtain  the  hydrate  perfectly  pure.  I  have  always  found 
indications  of  (NH4)2  S04  in  that  part  of  the  solution,  which  was 
ready  to  be  treated  with  ether.  However,  it  did  not  interfere  with 
the  process. 
This  last-named  solution  contains  a  large  amount  of  glucose, 
which,  according  to  my  dissertation,  could  not  have  existed  as  such 
in  the  original  alcoholic  extract.  It  again  shows  the  large  amount 
of  decomposed  glucoside,  and  through  the  presence  of  some  of  this 
glucose,  the  error  was  made  that  villosin  reduces  Fehling. 
Enclosed  you  will  find  a  sample  of  villosin,  about  4  grains  being 
the  entire  product  of  3  pounds  of  bark,  and  also  the  decomposition 
product  which  separated  out  during  its  preparation. 
According  to  this,  villosin  would  only  be  present  in  the  bark  to 
the  amount  of  0-019  per  cent.,  and  not  0-8  per  cent,  as  was  stated 
in  my  thesis.    Whether  I  had  been  working  at  that  time  with  a 
