6  Arbutin  in  Kalmia  Latifolia,  Lin.  {^"^■^^^'iS^"""^ 
of  the  fresh  leaves  were  collected  by  the  writer  and  carefully  dried  in  a 
room,  when  they  were  found,  upon  reweighing,  to  have  lost  sixty-three 
per  cent.  The  dried  leaves  were  coarsely  powdered  and  treated  with 
boiling  water  for  several  hours,  strained  and  expressed,  and  again  treated 
in  a  similar  manner.  The  mixed  decoctions  were  precipitated  with 
acetate  of  lead  and  filtered,  the  filtrate  was  then  submitted  to  the  action 
of  sulphuretted  hydrogen  to  remove  all  the  lead  ;  the  liquid  is  again 
filtered  and  evaporated  to  the  consistence  of  a  soft  extract.  The  evapo- 
ration in  the  first  experiment  was  carried  too  far,  leaving  a  viscid^ 
reddish-colored  mass,  in  which,  after  standing  several  days,  no  crystals 
of  arbutin  were  perceptible.  Another  lot  of  the  leaves  was  gathered,  a 
strong  infusion  was  made,  filtered  and  evaporated  to  a  solid  consistence. 
The  aqueous  extract  thus  obtained  was  treated  with  alcohol,  the  residue 
was  a  viscid  mass  containing  the  kinic  acid,  if  present,  perhaps  in  com- 
bination with  calcium,  this  being  insoluble  in  alcohol.  An  aqueous 
solution  was  next  formed  of  this  substance  and  allowed  to  evaporate  at 
a  gentle  heat,  when  crystals  of  the  kinate,  if  present,  should  have  been 
deposited  ;  but,  as  in  the  preceding  examination,  I  was  disappointed. 
Another  experiment  was  made  similar  to  the  first,  with  the  exception 
that  the  liquid,  after  being  treated  with  acetate  of  lead  and  sulphuretted 
hydrogen,  was  not  evaporated,  so  much  and  I  was  this  time  rewarded 
with  the  separation  of  arbutin  in  crystals,  repeated  experiments  giving 
the  same  satisfactory  results.  A  few  crystals  were  separated  from  the 
mass  to  which  they  were  adhering  and  dissolved  in  water.  The  solu- 
tion was  made  alkaline  by  ammonia  as  directed  by  Jungmann,  and 
phosphomolybdic  acid  added,  when  immediately  the  beautiful  blue  color 
characteristic  of  arbutin  was  produced.  Quite  a  weak  infusion  of  IJva 
ursi  was  at  the  same  time  made  and  tested  as  above,  which  gave  the 
same  blue  color.  If  an  impure  solution  is  examined,  which  with  am- 
monia will  make  an  orange  color,  the  phosphomolybdic  acid  added  to 
this  will  change  it  to  a  bluish  green.  Kalmia  latifoUa  does  not  contain 
arbutin  so  largely  as  IJva  ursi;  the  yield  from  the  mountain  laurel  was 
so  small  that  I  did  not  separate  it  from  the  adhering  mass.  The  process 
of  Kawalier  is  certainly  a  very  good  one  as  to  simplicity  of  extraction^ 
with  the  exception  of  acetate  of  lead,  for  which  the  basic  salt  may  be 
substituted  with  advantage,  to  separate  gum  and  coloring  principles,  the 
presence  of  which  will  retard  the  crystallization  of  the  arbutin. 
Besides  arbutin,  the  presence  of  gum,  tannin,  lime  and  iron  were 
noticed  incidentally. 
Potts'ville,  Pa,,  December  5,  1874. 
