Am.  Joub.  Pharm.  ) 
.May  1,1871.  / 
Uva  ursi. 
203 
■ficult  to  remove  on  account  of  the  large  amount  of  black,  gummy  ex- 
tractive adhering  to  it.  The  crystals  contained  in  this  mass  could  only 
he  obtained  after  long  and  repeated  treatment  with  animal  charcoal; 
to  remove  coloring  matter  and  other  impurities,  it  might  be  purified 
\)j  precipitating  the  coloring  matter  by  a  solution  of  alum,  but  this 
■mode  of  proceeding  can  only  be  recommended  when  arhutin  is  the 
only  object  in  view,  otherwise  it  is  objectionable,  as  it  complicates  the 
process.  A  quicker  wa3%  however,  to  obtain  the  crystals,  I  found  to  be 
"by  treating  the  extractive  mixture  with  a  mixture  of  alcohol  and 
ether,  in  which  they  readily  dissolve,  leaving  behind  nearly  all  the 
impurities  ;  as  thus  obtained  the  crystals  have,  in  their  moist  condi- 
tion, a  yellowish  color,  becoming  nearly  white  when  dried;  they  pos- 
sessed the  same  properties  as  those  obtained  previously. 
All  the  crystals  obtained  by  these  different  processes  proved  to  be 
m^hutin,  the  discovery  of  which  was  first  announced  by  Kawalier  in 
1852. 
A  second  quantity  of  leaves  was  reduced  to  a  coarse  powder, 
decocted  with  water,  the  decoction'  strained  and  precipitated  with 
neutral  acetate  of  lead,  the  precipitated  lead  salt  was  filtered  off 
and  the  filtrate  was  treated  with  basic  acetate  of  lead,  until  a  precipi- 
tate was  no  longer  produced,  this  being  filtered  out.  Sulphuretted 
hydrogen  gas  was  passed  in  the  filtrate  until  all  the  lead  was  precipi- 
tated ;  the  sulphuret  of  lead  was  then  removed  by  a  filter,  and  the  excess 
•of  hj^drosulphuric  acid  by  heating  the  filtrate  ;  this  was  evaporated  to 
a  soft  extract,  redissolved  in  water,  treated  with  animal  charcoal,  then 
again  filtered  and  evaporated  and,  while  hot,  set  aside.  After  about  24 
hours  standing  the  bottom  of  the  vessel  was  covered  with  bunches  of 
small  crystalline  needles  of  arbutin  ;  these  were  pressed  and  dried 
between  filtering  paper  and  purified  by -redissolving  them  in  a  small 
quantity  of  boiling  water,  and  again  allowing  the  crystals  to  separate; 
these  when  pressed  and  dried,  consisted  of  small  prismatic  needles 
having  a  silvery  lustre.  This  second  process  for  obtaining  the  arbu- 
tin is  in  the  main  points  the  original  one  of  Kawalier,  except  that  he 
does  not  precipitate  with  basic  acetate  of  lead,  which,  however,  re- 
moves nearly  all  the  gum  and  coloring  matter,  and  thereby  facilitates 
the  crystallization  to  some  extent. 
Arbutin  generally  crystalizes  from  ether  in  prismatic  needles  of 
"Considerable  size  and  perfectly  colorless  from  an  alcoholic  solution,  in 
.small  acicular  crystals  of  a  white  color,  and  in  small  bunches  of  needles 
