446      PREPARATION  OF  THE  OIL  OF  CROTON  TIGLIUM,  ETC. 
and  found  it  to  consist  of  ordinary  black  nutgall  ink,  with  an 
admixture  of  crude  wood  vinegar  and  solution  of  indigo.  He 
gives  the  following  formula  for  preparing  such  an  ink,  which,  in 
all  its  properties,  is  identical  with  the  commercial  article  : — 
100  parts  of  powdered  nutgalls  are  digested  with  1200  parts, 
by  weight,  of  crude  wood  vinegar  at  a  moderate  heat  for  several 
days,  then  transferred  to  a  filter,  and  washed  with  crude  vinegar 
until  the  nitrate  weighs  1200  parts.  In  this  clear  brown  liquor, 
12  parts  of  green  vitriol  and  50  parts  of  gum  arabic  are  dissolved, 
this  solution,  under  frequent  agitation,  set  aside  for  several  days, 
and  at  last  so  much  solution  of  indigo  added  to  make  the  whole 
1500  parts,  when  immediately  the  ink  assumes  that  peculiar 
dark  green  tint.  The  solution  of  indigo  was  made  by  dissolving 
one  part  of  indigo  in  4  parts  of  Nordhausen  oil  of  vitriol,  dilut- 
ing with  water,  precipitating  with  carbonate  of  potassa,  filtering, 
and  washing  the  precipitate  with  water.  When  the  sulphate  of 
potassa  is  nearly  washed  away,  the  blue  precipitate  commences 
to  dissolve  ;  and  this  solution  of  the  precipitate — the  so-called 
indigocarmine — was  used. — ( Wittstein  s  Vierteljahrsschrift,  v. 
225.)  J.  M.  M. 
PREPARATION  OF  THE  OILS  OF  CROTON  TIGLIUM,  NUTMEGS, 
AND  LAUREL  BERRIES  BY  MEANS  OF  SULPHURET  OF  CAR- 
BON. 
By  M.  Lepage,  of  Gisors. 
M.  Lepage,  taking  advantage  of  the  great  solvent  power  of 
bi-sulphuret  of  carbon,  in  view  of  the  low  price  at  which  it  can 
now  be  had  in  France,  has  prepared  it  as  a  means  of  extracting 
medicinal  fixed  oils  from  the  tissues  of  plants  containing  them. 
Croton  Oil — The  croton  seeds,  well  divided  by  grinding,  are 
introduced  into  a  bottle  with  three  times  their  weight  of  sulphu-1 
ret  of  carbon,  which  has  been  carefully  rectified ;  allow  it  to  stand 
twenty-four  hours,  with  occasional  agitation,  and  then  express 
rapidly  in  a  cloth.  The  dregs  are  mixed  again  with  two  parts 
of  that  solvent  in  the  bottle,  macerated  again  for  twenty-four 
hours  and  again  expressed  strongly.  The  two  products  are  united, 
filtered  in  a  covered  funnel,  and  then  subjected  to  distillation  in 
a  glass  retort  with  a  water  bath  heat,  with  a  good  condensing 
