41 6  Alkaloids  of  Pomegranate  Bark.  {^""InZS^^ 
is  again  resorted  to,  wnich  continues  for  three  or  four  hours,  when  the 
boiling  mass  is  poured  ofF  and  strained  through  a  filter.  This  filter  is 
composed  of  a  brick  vat  covered  with  stucco,  i8  to  20  feet  long,  6  feet 
wide,  and  about  3  feet  deep  ;  it  is  covered  with  bamboos,  on  which 
are  spread  rush  mats,  and  over  these  a  strong,  well  stretched  linen 
cloth.  On  this  cloth,  after  the  liquid  has  been  strained  through,  there 
remains  a  thick,  deep  blue  paste,  almost  black. 
The  water  which  was  in  the  vat,  in  flowing  through  the  filter,  leaves 
this  deposit  of  indigo.  The  paste  is  then  placed  in  small,  solidly  con- 
structed wooden  cases,  perforated  with  small  holes,  and  with  a  very 
strong  linen  cloth  at  the  bottom  ;  the  cases  are  then  covered  with 
cloth,  and  a  wooden  lid  perforated  also  with  small  holes  ;  they  are 
then  pressed  in  a  vise  to  extract  every  particle  of  moisture.  When 
this  operation  is  completed,  the  indigo  is  found  in  a  large  thick  block, 
the  cutting  of  which  demands  careful  attention,  and  must  be  done  very' 
slowly.  The  blocks  are  then  submitted  to  the  action  of  the  drying- 
ground,  which  consists  of  a  large  brick  building  of  a  good  height,  with 
windows  furnished  with  closed  lattices  to  exclude  the  rays  of  the  sun, 
even  thick  bushy  trees  being  planted  all  round  the  buildings  to  assist  in 
keeping  out  the  light.  The  cakes  occupy  from  three  to  five  days  in 
drying,  and  are  then  sent  to  Calcutta.  It  is  m  this  state  that  indigo  is 
delivered  into  the  market;  its  quality  may  be  tested  by  its  lightness  or 
small  specific  gravity,  and  its  bright  color  when  rubbed  with  the  nail. 
— Pharm.  Jour,  and  Trans. ^  May  15,  1880. 
THE  ALKALOIDS  OF  POMEGRANATE  BARK.' 
By  C.  Tanret. 
In  March,  1879,"  the  author  announced  that  in  pursuing  his  chemi- 
cal investigation  of  pomegranate  bark  he  had  established  the  fact  that 
pelletierine,  the  alkaloid  previously  isolated  by  him,  is  accompanied  in 
the  bark  by  three  other  alkaloids,  two  of  which,  like  pelletierine,  are 
liquid  and  one  is  crystallizable,  all  four  being  volatile.  In  the  present 
communication  the  author  describes  the  principal  properties  of  these 
alkaloids  and  the  method  adopted  by  him  for  their  separation. 
In  the  first  place  a  mixture  of  the  salts  of  the  alkaloids  is  prepared, 
'    Comptes  Rendus,"  vol.  xc,  p.  695. 
^♦'Comptes  Rendus,"  vol.  Ixxxviii,  p.  716. 
