ON  THE  SO-CALLED  ALIZARIN  INK. 
445 
Instead  of  using  carbonate  of  soda,  very  likely  the  oxides  may 
be  precipitated  from  a  hot  solution  by  potassa  and  reduced  as  above 
stated. 
This  process  is  a  simple  one,  and  the  operation  takes  but  little 
time.—  Ibid.  p.  144.  J.  M.  M. 
PREPARATION  OF  CUMARIN. 
By  Prof.  "Woehler. 
According  to  Dr.  Goessmann,  the  best  way  to  obtain  cumarin 
is  by  the  following  process  :  Tonka  beans  are  cut  finely,  and  with 
about  their  volume  of  80  per  cent,  alcohol  heated  to  near  the 
boiling  point ;  after  filtering,  the  residue  is  again  treated  in  the 
same  manner.  Of  the  mixed  liquors,  alcohol  is  distilled  off  until 
they  become  turbid,  and  are  then  mixed  with  about  four  times 
the  volume  of  distilled  water,  by  which  a  crystalline  precipitate 
of  cumarin  is  produced.  The  mixture  is  boiled  and  run  through 
a  filter  moistened  with  water,  which  keeps  the  precipitated  fat 
back  ;  pure  cumarin  crystallizes  from  the  solution  on  cooling.  By 
concentration  of  the  mother  liquor,  the  balance  may  be  obtained, 
which,  if  not  quite  colorless,  must  be  purified  by  animal  charcoal. 
By  this  process  Mr.  Eastwick,  Jr.,  obtained  over  8  grammes  of 
cumarin  from  one  pound  of  tonka  beans. — Ibid.  p.  66. 
J.  M.  M. 
ON  THE  SO-CALLED  ALIZARIN  INK. 
By  J.  WlNTERNITZ, 
Every  one  who  knows  alizarin,  the  red  coloring  principle  of 
dyer's  madder,  will  expect  a  red  ink  to  which  the  name  of  aliza- 
rin ink  is  applied,  and  he  cannot  fail  to  be  astonished  to  find  it, 
instead  of  a  red,  of  a  dark  green  color,  and  the  writings  with  it 
soon  change  to  dark  blue  and  black.  The  above  name,  therefore, 
is  a  mystification,  invented  to  conceal  its  ingredients  and  mode 
of  preparation,  and  to  mislead  an  attempted  analysis.  No  doubt 
many  have  tried  in  vain  to  prepare  such  an  article  as  it  has  ap- 
peared in  commerce  a  short  time  since,  from  madder,  but  ob- 
tained an  entirely  different  product. 
The  author  has  made  an  analysis  of  alizarin  ink  of  commerce, 
