^■"pJ^b^iSo^"^}  ^^^^  Coloring  Principle  of  Frasera  Walteri,  73 
phuric  acid,  a  yellow  oily  substance  rose  upon  the  surface  and  the 
crystals  disappeared.  Upon  cooling,  this  substance  solidified  to  a  waxy 
consistence  and  sunk  to  the  bottom  of  the  tube.  The  supernatant 
colorless  liquid  was  filtered,  neutralized  with  carbonate  of  calcium, 
filtered  again  and  the  filtrate  tested  with  Fehling's  solution  ;  no  pre- 
cipitate. 
The  crystals  change  cold  ammonia  water  to  yellow,  but  do  not  neu- 
tralize it.  With  cold  concentrated  solution  of  caustic  potash  or  caustic 
soda  no  change  is  apparent  ;  upon  boiling,  the  crystals  turn  orange-red. 
Dilute  solution  of  caustic  potash  turns  yellow,  but  is  not  neutralized. 
Upon  heating  them  with  caustic  potash,  no  evolution  of  ammonia 
resulted. 
All  attempts  to  obtain  the  reaction  of  an  alkaloid  or  an  acid  with  the 
ordinary  reagents  from  any  solution  of  the  crystals  resulted  in  failure. 
These  crystals  are  those  of  an  indifferent  organic  body  differing 
from  any  heretofore  examined  by  the  writer.  The  process  em- 
ployed in  obtaining  it  is  so  simple  as  to  forbid  the  idea  that  the  crys- 
tals are  a  product  of  manipulation  and  the  result  of  a  splitting  up  of 
some  natural  compound,  which  might  result  when  excessive  or  long- 
continued  heat  is  resorted  to,  or  the  use  of  chemicals.  It  may  be  safelv 
accepted  that  this  substance  is  ^,  perhaps  the^  principal  coloring  matter 
of  the  root. 
Reasoning  from  the  foregoing,  and  comparing  the  process  employed 
bv  mvself  with  those  of  preceding  investigators,  I  think  it  may  safely 
be  supposed  that  the  same  substance,  in  a  more  or  less  impure  state, 
was  previously  obtained.  To  the  first  investigator,  Mr.  Douglass,  may 
well  be  ascribed  the  credit  of  the  discovery,  since  he  concluded  the 
substance  obtained  by  himself  to  be  a  yellow  coloring  principle  mixed 
with  gallic  acid.  Again,  others  state  that  as  obtained  by  themselves  it 
was  partially  soluble  in  chloroform,  and  we  may  well  infer  the  insoluble 
matter  to  have  been  impurities. 
Adhering  to  the  crude  crystalline  masses  of  mixed  crystals  I  founds 
as  might  be  supposed,  a  small  amount  of  grape  sugar.  Accompanying 
this  paper  I  send  an  ample  quantity  of  the  mixed  crystalline  matters 
obtained  by  myself.  They  have  been  washed  with  cold  alcohol  to 
separate  the  adhering  bitter  substance.  Also  a  supply  of  the  purified 
yellow  crystalline  substance  [A). 
