Am.  Jour.  Pharm.  ) 
May  1,1871.  / 
TJva  ursi. 
205 
of  arbutin,  I  was  led  to  suppose  that  the  two  might  perhaps  be  identi- 
cal ;  to  satisfy  myself,  I  prepared  some  ursin  according  to  Hughes' 
method^  which  consists  in  maceration  and  percolation  of  the  leaves 
with  cold  water,  precipitating  the  tannin  by  a  solution  of  gelatin,  fil- 
tering and  evaporating  to  dryness,  treating  the  remaining  extract 
by  strong  alcohol,  the  alcoholic  solution  with  animal  charcoal, 
filtering  and  evaporating  spontaneously.  By  this  process  an  acicular 
crystalline  mass,  to  which  a  small  quantity  of  resin  adhered,  was  ob- 
tained having  nearly  all  the  properties  of  arbutin  ;  the  solution  ren- 
dered alkaline,  produced  a  blue  color  with  phosphosmolybdic  acid, 
and  it  yielded,  when  boiled  with  dilute  sulphuric  acid,  the  same  pro- 
duct of  decomposition,  hydrokinone,  besides  separating  ericolin. 
Hughes  states,  however,  that  his  ursin  was  precipitated  by  carbon- 
ate of  potassa  and  by  the  solution  of  subacetate  of  lead,  while  it  was 
not  afiected  by  the  tincture  of  chloride  of  iron  ;  but  as  he  uses  a  solu- 
tion of  gelatin  to  precipitate  the  infusion  of  the  leaves,  he  only  gets 
rid  of  the  tannic  acid  while  the  gallic  acid  remains  in  solution,  and  is 
afterwards  obtained  together  with  the  arbutin,  (his  ursin).  A  solu- 
tion of  this  mixture,  then,  of  course  precipitates  with  basic  acetate  of 
lead,  but  then  it  ought  to  be  affected  by  the  salts  of  iron  ;  but  the  tincture 
which  he  used  is  a  very  uncertain  test,  owing  to  the  free  acid  it  con- 
tains, which  does  not  indicate  small  quantities,  as  in  this  case,  while 
the  solution  of  subacetate  of  lead  precipitates  even  the  smallest  trace 
of  gallic  acid.  Carbonate  of  potassa  would  produce  a  slight  change 
in  the  color,  but  an  actual  precipitation  did  not  take  place.  The  ursin 
of  Hughes  must  therefore  be  considered  as  an  impure  arbutin. 
[The  author  then  minutely  describes  the  action  of  nitric  acid  on 
arbutin  and  the  production  of  binitro-arbutin,  discovered  byStrecker; 
also,  the  decomposition  of  this  compound  into  sugar  and  binitro- 
hydrokinone,  after  which  the  effect  of  chlorine  upon  arbutin  is  con- 
sidered.] 
Arbutin  has  also  been  found  abundantly  in  Chimapliila  umhelJata^ 
and  it  probably  exists  in  a  number  of  ericaceous  plants.  Its  medical 
properties  have  never  been  practically  applied  ;  it  was  at  one  time  be- 
lieved to  represent  the  diuretic  properties  of  Uva  ursi,  and  Hughes 
states  that  one  grain  of  his  ursin  proved  a  powerful  diuretic.  The 
celebrated  pharmocologist,  Dr.  Schrofi"  of  Vienna,  who  experimented 
with  pure  arbutin,  states,  however,  that  it  possesses  no  diuretic  pro- 
