^""jiiy'iss^s^™'}      Arbutin  the  Bitter  Principle  of  Cowberry.  823 
with  ammonia  and  phosphomolybdic  acid  the  above  described  blue 
color.  Crystals  of  arbutin,  however,  could  not  be  obtained,  which 
was  probably  due  to  the  very  small  amount  of  it  present  in  the  small 
sample  of  berries.  If  the  blue  color  formed  in  liquids  by  ammonia 
and  phosphomolybdic  acid  is,  as  is  suggested  in  this  Journal,  character- 
istic for  the  presence  of  arbutin,  there  can  be  no  doubt  that  the  for- 
mation of  it  in  the  filtered  juice  of  the  American  cranberries  proves 
the  presence  in  them  of  this  bitter  principle. 
Note  by  the  Editor. — The  above  paper  is  an  interesting  and  important 
one,  on  a  subject  of  phytochemistry  which  has  received  considerable  atten- 
tion in  previous  vohniies  of  this  Journal.  Thus  far  the  existence  of  arbutin 
has  been  proven  for  the  leaves  of  a  number  of  sempervirent  species  of  the 
groups  Ericineie  and  Pyrolese,  of  the  natural  order  of  Ericaceae ;  Mr. 
CJaassen's  paper  shows  the  same  principle  also  to  exist  in  the  leathery 
leaves  of  a  plant  of  the  group  Vaccineae,  thus  rendering  it  more  probable 
that  arbutin  may  be  found  in  all  ericaceous  plants,  at  least  in  those  with 
leathery  leaves.  In  1871  ("Am.  Jour.  Phar.,"  1871,  p.  235)  we  pointed  out 
the  possibility  of  the  identity  of  vacciniin  with  arbutin.  When,  in  1874 
{Ibid.^  1874,  p.  315),  we  thought  the  former  might  possibly  be  calcium 
kinate,  we  overlooked  Mr.  Claassen's  statement  [Ibid.,  1870,  p.  208),  that 
the  principle  is  not  precipitated  by  subacetate  of  lead  ;  moreover,  calcium 
kinate  crystallizes  in  a  difTerent  form  (four-sided  scalesj,  is  insoluble  in 
alcohol,  and  is  tasteless.  We  are  indebted  to  Mr.  Claassen  for  specimens 
of  both  principles. 
The  results  obtained  as  above  make  it  of  interest  to  ascertain  the  beha- 
vior of  the  leaves  of  the  American  cranberry,  an  investigation  which  Mr. 
Claassen  informs  us  he  will  soon  undertake. 
Choline  in  Hops. — Drs.  Griess  and  G.  H.  Harrow  have  separated 
choline,  C2H4(OH).NMe3.0H,  from  hops  by  adding  to  a  concentrated 
extract,  acidified  with  chlorhydric  acid,  a  solution  of  iodine  in  iodhy- 
dric  acid.  The  semi-solid  precipitate  obtained,  a  choline  periodide 
was  boiled  with  water  to  expel  iodine,  and  the  resulting  solution  of 
choline  iodide  treated  with  silver  oxide ;  the  impure  choline  in  the 
solution  was  then  converted  into  the  auro-chloride,  which  was  recrys- 
tallized.  In  this  manner  they  have  not  been  able  to  obtain  more  than 
^\j-th  per  cent,  of  choline  from  hops.  They  consider  it  not  improbable 
that  it  exists  in  loose  combination  with  resin,  as  they  find  that  a  very 
dilute  aqueous  solution  is  capable  of  dissolving  comparatively  large 
quantities  of  hop  resin,  the  liquid  being  then  of  an  intensely  bitter 
taste.  Employing  the  same  method,  they  have  also  extracted  choline 
from  beer.  — C/iem.  News,  March  27,  1885,  p.  149. 
