^bemb^iS?!0'}     Coloring  of  Various  Tannin  Matters.  623 
principle  as  one  of  the  products.  The  acetyl  derivative  of  this 
crystallized  from  alcohol  in  colorless  needles  melting  at  1890  to 
191  °.  By  fusion  with  alkali  two  crystalline  decomposition  products, 
namely,  phloroglucinol  and  protocatechuic  acid,  were  obtained.  These 
properties,  together  with  an  examination  of  its  dyeing  and  other 
properties,  clearly  showed  the  coloring  principle  resulting  from  the 
decomposition  of  the  foregoing  glucoside  to  be  quercetin. 
To  ascertain  the  nature  of  the  sugar  liberated  in  the  above  action, 
the  osazone  derivative  was  prepared.  This  consisted  of  glistening 
yellow  needles  melting  at  205  °,  and  was  apparently  dextr osazone. 
Of  the  three  distinct  glucosides  of  quercetin  which  have  been 
described,  the  one  under  consideration  was  found  to  resemble 
viola-quercitrin,  in  that  it  yielded  quercetin  and  glucose  on  decompo- 
sition. The  author  proved,  however,  that  they  were  not  identical, 
and  proposed  to  name  the  substance  obtained  by  him  Osyritin  from 
Osyris  compressa,  another  name  for  Cape  sumach. 
The  tannin  obtained  from  the  filtrate,  from  which  the  osyritin  had 
been  separated,  was  examined  to  determine  its  general  characters. 
It  was  found  to  be  a  tannin  glucoside,  and  to  closely  resemble  quino- 
tannic  acid  and  quinovatannic  acid,  which  are  decomposed  by  acid 
into  a  sugar  and  an  anhydride,  and  yield  protocatechuic  acid  on 
fusion  with  alkali. 
A  study  was  mide  of  the  coloring  principles  of  the  two  varieties 
of  commercial  catechu,  namely,  gambier  and  acacia  catechus.  The 
identity  of  the  coloring  principle  of  the  former  variety  with  quercitin, 
as  reported  by  Lowe  {Zeit.  anal.  Chem,,  1 874, 12,  1 27),  was  confirmed, 
and  while  the  properties  of  the  principle  from  the  latter  variety  in- 
dicated that  it  was  also  identical,  it  was  not  obtained  in  sufficient 
quantity  for  ultimate  analysis,  400  grammes  of  catechu  yielding  only 
0-05  grammes  of  coloring  matter. 
Rhus  cotinus,  the  Venetian  variety  of  sumach,  next  received  at- 
tention, and  the  coloring  principle,  determined  to  be  myricetin  in- 
stead of  quercetin,  as  reported  by  Lowe.  It  yielded,  with  dilute 
alkalies,  a  deep  green  solution,  and  its  acetyl  derivative  crystallized 
in  colorless  needles,  melting  at  203°-204°.  Owing  to  the  excessive 
adulteration  which  is  practised  with  this  product,  the  author  does 
not  consider  his  results  in  this  case  as  final,  but,  nevertheless,  regards 
them  as  extremely  suggestive. 
Of  other  tannin  matters,  the  following  fruits  and  seeds  were  ex- 
