398         NOTES  AND  QUERIES  ON  PRACTICAL  PHARMACY. 
was  obliged  after  a  two  days'  skirmish  with  four  ounces  of  them, 
to  put  them  into  the  menstruum  not  half  so  well  powdered  as  I 
could  wish. 
QWe  know  of  no  better  method  of  comminuting  these  seeds,  than  by 
first  drying  them  well  and  then  subjecting  them  in  small  quantities  at  a 
time  to  the  action  of  the  pestle  in  an  iron  mortar.  Every  thing  depends  on 
the  proper  relative  curves  of  the  pestle  and  mortar.  They  should  have 
nearly  the  same  radius. — Editor.]] 
Displacement  Process. — One  hint  to  beginners.  See  that  your 
lower  diaphragm  fits  well,  and  that  the  cloth  stretched  over  it  is 
equally  engaged  all  round  its  edge,  between  it  and  the  body  of 
the  instrument,  else  you  may  have  your  packing  to  do  all  over 
again  from  the  clogging  of  the  beak.  Another  thing,  you  can 
pack  arnica  and  chamomile,  and  substances  of  similar  texture, 
much  more  evenly  and  closely,  after  putting  them  through  Swift's 
drug  mill,  or  some  similar  machine,  than  you  can  without  so  doing, 
and  obtain  a  better  result. 
Tinctura  Ferri  Muriatis  I  have  noticed  one  or  two  articles 
upon  this  subject  in  recent  numbers  of  the  journal,  and  now  offer 
a  suggestion.  Is  not  the  difficulty  complained  of  and  often  ex- 
perienced in  dissolving  the  carbonate  of  iron  in  the  acid,  due  to 
the  careless  preparation  of  the  former  ?  I  am  induced  to  believe 
so,  from  a  recent  occurrence  in  my  establishment.  A  lady  to 
whom  I  had  sold  two  ounces  of  the  carbonate  of  iron,  returned 
it  on  account  of  the  difference  in  taste  and  therapeutical  effect 
from  what  she  had  experienced  from  other  samples  which  I  had 
sold  her.  I  immediately  examined  it  and  found  indeed  that  it 
was,  to  say  the  best,  a  very  carelessly  made  preparation.  There 
was  some  chalybeate  taste,  but  a  nauseous  saline  taste  was  the 
most  marked  feature.  It  was  not  subjected  to  analysis,  because 
a  notable  mixture  of  sulphate  of  soda  was  too  evident  to  be  mis- 
taken. This  occurrence  suggested  the  query  whether  the  diffi- 
culty of  dissolving  some  samples  of  carb.  ferri  in  muriatic  acid 
might  not  be  due  to  some  impurity  of  the  salt.  And  I  am  the 
more  disposed  to  think  so,  as  the  last  time  I  made  tinct.  ferri 
muriatis,  the  carbonate  of  iron  employed  was  entirely  dissolved 
by  the  acid,  without  the  aid  of  heat,  or  anything  else  but  stirring 
with  a  glass  rod.* 
*[Note. — The  difficulty  arises  most  frequently  where  the  acid  has  the 
proper  strength,  not  from  impurity  but  from  the  dehydration  of  the  subcar* 
