METHODS  OF  MAKING  MEDICINES  AGREEABLE,  ETC. 
525 
that  they  contain  no  air  bubbles,  and  the  empty  capsules  weigh 
only  from  1J  to  2|  grains,  whereas  the  gelatin  capsule  weighs 
nearer  10  grains. 
The  empty  capsule,  another  French  idea,  although  now  made 
largely  in  this  country,  consists  of  two  short,  thin  cylinders  of 
gelatin,  closed  at  one  end,  and  sliding  one  over  the  other  at 
their  open  ends.  These  are  made  of  several  sizes,  and  all  that  is 
required  in  order  to  use  them  is  to  fill  the  smaller  cylinder  with 
the  medicine,  whether  solid  or  liquid,  place  the  other  over  it,  and 
having  allowed  it  to  soften  in  the  saliva,  it  is  as  easily  swallowed 
as  a  morsel  of  bread. 
The  tasteless  French  wafer  is  another  method  of  taking 
powders  ;  they  are  made  white  and  tasteless,  diameter  about  3j 
inches,  and  are  used  by  moistening  the  edges  of  the  wafer  with 
saliva,  placing  the  powder  in  the  center ;  and  folding  the  edges 
over  the  center  thus  enveloped,  the  medicine  is  taken  without 
being  tasted. 
Numberless  methods  are  proposed  for  covering  the  taste  of 
cod  liver  oil,  none  of  which  are  so  simple  and  free  from  ob- 
jections as  that  of  chewing  some  bitter  substance,  as  orange 
peel,  previous  to  taking  the  dose.  Emulsions  of  cod  liver  oil 
are  elegantly  prepared  by  means  of  carbonate  of  potassa,  orange 
flower  water  and  syrup.  Many  physicians  prescribe  cod  liver 
oil  in  brandy,  which  tends  to  cover  its  taste  and  aids  its  medi- 
cinal action. 
Castor  oil  is  not  improved  in  medicinal  action  by  most  of  the 
methods  used  to  disguise  it,  and  the  method  of  giving  it  float- 
ing  between  spirit  and  water  is  doubtless  the  best,  which  is  as 
follows:  in  a  proper  cup  place  an  ounce  or  two  of  mint  water, 
milk  or  cold  infusion  of  coffee,  and  having  thoroughly  wet  the 
sides  of  the  cup  with  it,  pour  the  dose  of  oil  carefully  into  the 
center  of  it,  pour  upon  this  a  little  brandy  or  any  agreeable 
alcoholic  tincture ;  the  oil  thus  prepared  can  be  swallowed  with- 
out its  touching  the  mouth  at  all,  being  completely  enveloped  by 
its  aqueous  and  alcoholic  vehicle.  The  essential  oil  of  spear- 
mint possesses  the  power  of  covering  the  taste  of  copaiba,  in 
emulsions  of  that  substance,  in  a  remarkable  degree. 
Since  fluid  extracts  were  made  officinal  by  the  last  revision  of 
the  United  States  Pharmacopoeia,  the  number  of  plants  which 
