464  Noie.^  on  Alnmoi,  B.  P.  / Am  jour  pi.ami. 
'  (      Sept.,  1882. 
that  even  in  this  respect  it  will  resemble  the  latter  much  more  chisel v 
if  permitted  to  remain  in  the  ground  for  5  or  6  years.  The  commer- 
cial article  is  said  to  yield  extracts,  tinctures  and  infusions  which,  not 
only  in  color,  odor  and  taste,  but  likewise  in  activity,  compare  favor- 
ably with  the  corresponding  preparations  of  Chinese  rhubarb.  The 
author  urges  the  employment  of  this  rhubarb,  partly  for  patriotic  rea- 
sons as  far  as  Austria-Hungary  is  concerned,  but  chiefly  on  account  of 
its  low  price  and  its  good  effects,  these  being  fully  secured  if  5  parts  of 
Moravian  rhubarb  be  used  in  place  of  4  parls  of  the  Chinese  root, 
as  was  pointed  out  already,  in  1808,  by  Trommsdorff. — Phar.  Post,, 
June  16,  1882,  p.  206—209. 
NOTES  ON  ALUMEN,  B.  P. 
By  W.  Watson  Wilt.. 
Ammonio-aluminic  sulphate  manufacture  seems  to  have  become  a 
thing  of  the  past,  and  great  difficulty  is  now  experienced  by  pharma- 
cists in  obtaining  it,  the  potassic  salt  having  entirely  taken  its  plac(>. 
No  doubt  the  consumption  of  alum  from  a  pharmaceutical  point  of 
view  is  small  in  comparison  to  the  enormous  quantities  used  in  the  arts 
and  manufactures  of  this  country,  but  I  think  if  there  had  been  a  per- 
sistent demand,  however  small,  for  ammonia  alum,  its  manufacture- 
would  not  have  become  obsolete.  In  a  communication  I  had  from 
Mr.  R.  King,  of  Glasgow,  some  time  ago,  he  assured  me  there  was  no 
demand  for  ammonia  alum,  a  statement  fully  endorsed  by  Mr.  P^Spenee^ 
of  Pendleton,  in  a  note  I  had  from  him  regarding  this  subject.  Vari- 
ous have  been  the  processes  employed  in  tlie  preparation  of  ammonia 
alum,  some  makers  pre])aring  the  aluminum  sulphate  from  aluminous 
schist  or  shale,  others  using  clay  or  kaolin.  The  following  is  a  brief" 
resume  of  one  of  the  ])rocesses :  Shale  of  coal  measures,  previously 
calcined,  is  placed  in  iron  vessels  lined  with  lead,  and  sulphuric  acid 
from  an  adjoining  receiver  is  poured  over  it ;  the  mass  then  allowed 
to  digest  at  a  temperature  of  240°r.,  this  degree  of  temperature  being- 
sustained  by  a  fire  underneath  the  vessels  and  also  by  steam  and 
ammonia  vapor  being  blown  into  the  paii.  The  solution,  after  evapo- 
rating for  some  time,  is  poured  into  large  coolers  and  strongly  agitated 
to  prevent  formation  of  large  crystals.  The  deposit  of  fine  crystals,, 
commonly  called  "  flour  alum,"  is  now  washed  and  redissolved  by 
steam,  and  the  solution  run  ofl*  into  large  vessels,  called  "  reaching 
