Am.  Jour.  Pharm. ) 
July,  1883.  i 
Madder  Colors. 
365 
identified,  attached  to  it.  Nos.  7  to  11  are  adulterated  with  chrome, 
from  3  per  cent,  to  nearly  6  per  cent.  No.  10  has  the  addition  of  a 
very  small  percentage  of  turmeric,  and  No.  12  quite  5  per  cent,  of  that 
root.  It  is  not  to  be  assumed  that  excepting  these  slight  admixtures 
these  powders  are  genuine ;  for  although  undoubtedly  it  is  bad  enough 
when  having  ordered  a  hundredweight  of  insect  powder  one  finds  5  to 
7  pounds  of  chrome  yellow,  costing  4d.  to  lOcT.  j)er  pound,  as  part  of 
the  delivery,  the  presence  of  such  extraneous  color  is  suggestive  of  its 
being  merely  a  •  cloak  for  a  more  weighty  adulteration,  such  as  Mr. 
Conroy  has  discovered,  or  as  that  referred  to  by  Mr.  E.  V.  Riley 
(^^  Pharm.  Journ."  |  3],  vol.  xii,  789),  who  says  that  the  stalks  and 
leaves  are  ground  with  the  flowers  in  the  proportion  of  one-third  of 
their  weight ; "  whilst  on  the  authority  H.  Kalbruner  Pharm. 
Journ.'^  [3],  vol.v,  305),  "  The  plant  itself  (minus  the  flowers)  pow- 
dered appears  to  be  quite  inactive," 
In  face  of  the  foregoing  facts  it  seems  advisable  that  purchasers 
should  avoid  the  foreign  powder,  which  seems  to  be  always  colored, 
and  not  too  trustingly  accept  any  guarantee,  even  of  professed  grinders, 
but  verify  for  themselves  each  purchase,  which  by  the  means  above 
stated  can  readily  be  done  in  a  few  minutes  even  by  a  junior  assistant. 
— Pharm,  Jour,  and  Trans.,  May  19,  1883. 
MADDER  COLORS. 
By  a.  Wurtz. 
This  paper  is  a  report  drawn  up  by  Wurtz  on  a  memoir  of  Rosen- 
stiehl  on  the  coloring  matters  of  the  madder  root.  From  this  root 
five  separate  coloring  substances  can  be  extracted :  alizarin,  purpurin, 
madder-orange,  pseudopurpurin,  and  purpuroxanthin.  The  researches 
of  Graebe  and  Liebermann  have  fixed  the  constitution  of  the  two 
former,  whilst  Rosenstiehl  has  studied  more  especially  the  three  latter 
substances.  He  has  shown  that  purpuroxanthin  is  isomeric  with 
alizarin,  and  can  be  converted  into  purpurin  by  fusion  with  potash ; 
and  inversely  purpurin  can  be  reconverted  into  purpuroxanthin  by 
the  action  of  reducing  agents,  but  if  the  action  be  prolonged,  hydro- 
purpuroxanthin  is  formed.  Rosenstiehl  has  also  devised  a  new  method 
of  formation  of  purpurin.  On  heating  the  madder  root  with  sul- 
phurous acid,  Kopp  obtained  a  product  known  as  commercial  purpurin  ; 
as  this  substance  is  useless  for  dyeing  purposes,  it  has  been  customary 
