622      %  Coloring  of  Various  Tannin  Matters.  {ABeclmbefhm^: 
some  purposes,  among  which  may  be  mentioned  its  use  in  litho- 
graphic work. 
Such  a  slight  contamination  should  be  looked  upon  as  accidental, 
rather  than  wilful  adulteration,  and  those  who  buy  the  wax  from 
the  producer  should  carefully  examine  it  before  refining,  as  it  is  pos- 
sible for  it  to  have  its  origin  in  a  manner  which  is  very  well  known 
to  those  who  are  acquainted  with  the  details  of  apiculture,  namely, 
in  the  use  of  artificial  comb  foundation,  which  is  purchased  by 
many  bee-keepers  to  save  part  of  the  labor  of  the  colony  and  insure 
regularity  in  the  building  of  the  comb. 
Contaminations  originating  in  this  manner  are  frequent,  and  the 
blame  rests  upon  the  manufacturer  of  the  artificial  comb  foundation. 
305  Cherry  Street,  Philadelphia. 
THE  YELLOW  COLORING  PRINCIPLES  OF  VARIOUS 
TANNIN  MATTERS.1 
By  A.  G.  Perkin. 
The  author  continues  his  investigation  of  tanning  materials,  with 
the  object  of  studying  the  yellow  coloring  principle  which  is  so 
often  found  associated  with  the  tannin  in  plants,  and  also  for  the 
purpose  of  determining  the  relationship  between  the  coloring  matter 
and  tannin,  by  the  character  of  their  decomposition  products. 
Cape  sumach,  Colpoon  compressum,  was  first  examined.  The 
leaves  (which  constitute  the  part  utilized),  roughly  broken,  were 
extracted  in  a  Soxhlet's  apparatus,  first  with  ether  to  remove  wax 
and  chlorophyll,  and  then  with  alcohol,  which  dissolved  both  color- 
ing matter  and  tannin.  The  alcoholic  extract,  after  being  evaporated 
to'a  small  bulk,  was  poured  into  water,  and  the  mixture  extracted 
with  ether.  The  aqueous  liquid  was  freed  from  the  small  amount 
of  alcohol  remaining  by  distillation,  and  on  cooling  became  semi- 
solid, owing  to  the  production  of  crystals.  These  were  collected  and 
washed  with  ether,  chloroform,  and  dilute  alcohol  until  the  washings 
were  colorless.  The  yellow  product  obtained  was  further  purified 
by  crystallizations  from  dilute  alcohol  and  a  final  crystallization 
from  boiling  water. 
Experiments  showed  this  substance  to  be  a  glucoside,  which,  on 
decomposition  with  dilute  sulphuric  acid,  yielded  a  yellow  coloring 
1  Abstracted  from  the  Journal  of  the  Chemical  Society,  London,  October,  1897. 
