DISTILLED  WATERS  OF  THE  PHARMACOPCEIAS.      ,  437 
arrangement  should  be  adopted,  wherever  practicable,  for  having 
it  condensed  by  a  condenser,  used  for  no  other  purpose,  from  a 
source  of  steam  constantly  in  operation. 
"X  now  turn  to  the  other  waters,  which  seem  hitherto  to  have 
enjoyed  the  larger  share  of  attention,  and  these  for  the  sake  of 
convenience,  and  not  to  occupy  too  much  time,  by  considering 
each  separately,  I  have  arranged  in  three  divisions,  as  my  expe- 
rience has  led  me  to  consider  most  appropriate.  In  the  first 
division  I  have  placed  dill-seed,  caraway,  fennel,  cinnamon,  and 
pimento  waters,  in  the  preparation  of  which  I  am  of  opinion  that 
the  process  of  distillation  is  preferable  to  any  other,  as  they  are 
not  likely  to  be  contaminated  with  much  mucilaginous  matter, 
which  might  render  them  particularly  liable  to  become  sour  ;  of 
these  five,  the  fennel  and  pimento  give  the  most  trouble,  the  pi- 
mento continually  depositing,  for  which  I  have  found  no  better 
remedy  than  filtration  ;  the  fennel,  if  kept  long,  and  there  is 
not  a  large  demand  for  it,  becoming  ropy,  for  which  I  believe  a 
little  spirit  to  be  the  best  preventive. 
"  The  excess  of  oil  which  generally  passes  over  in  distilling 
these  waters,  where  the  material  acted  upon  is  good,  should  be 
shaken  well  up  with  the  water  and  transferred  to  the  stock  ves- 
sel, allowing  it  afterwards  to  separate,  and  when  required,  run- 
ning it  semi-opaque  as  it  may  be  into  the  ordinary  bottles  in 
daily  use  ;  the  oil  being  left  in  the  stock  vessel  assists  in  pre- 
serving the  water,  and  keeps  it  the  full  strength  to  the  last* 
Occasionally  remove  the  surplus  oil  when  a  fresh  supply  of  wa- 
ter is  put  in,  and  the  oil  so  collected  will  be  found  pure  and  fit 
for  every  purpose  for  which  it  may  be  required. 
"  In  the  second  division  I  place  peppermint,  spearmint,  and 
pennyroyal  waters,  and  in  preparing  these  I  consider  that  tritu- 
ration with  magnesia  or  fine  sand,  always  supposing  that  genuine 
oil  is  used,  answers  extremely  well ;  but,  as  with  the  former, 
they  should  be  kept  in  quantity,  made  some  days  before  required 
for  use,  allowed  to  settle,  and  drawn  off  as  wanted  without  being 
filtered.  I  can  see  no  objection  to  the  employment  of  magnesia, 
as  ordered  in  the  Pharmacopoeia  of  1836  ;  the  impression  held 
by  some  that  it  absorbs  the  oil,  and  reduces  the  strength  of  the 
water,  appears  to  me  an  erroneous  one.  Volatile  oils  are  not 
given  to  saponification. 
