A^vfmbei%Pi9iT  }        Prescription  Kinks  and  Hints.  505 
The  well  trained  pharmacist  is  exceedingly  careful,  when 
triturating  two  powders,  to  add  very  slowly  and  cautiously  the 
diluent  powder  to  the  more  active ;  yet,  very  often,  the  same  person 
fails  to  realize  the  importance  of  observing  the  same  procedure 
when  triturating  an  insoluble  powder  with  a  liquid.  Two  samples 
of  the  following  prescription  illustrate  the  importance  of  this : 
3 
Calaminse    gr.  40. 
Zinci  Oxidi    dr.  2. 
Liquor  Calcis   ■  .  . .  .fl.  oz.  4. 
M 
A  sample,  prepared  by  adding  the  lime  water  in  considerable 
quantities  at  the  start,  although  triturated  for  a  fairly  long  time, 
commenced  to  subside  immediately  after  being  shaken  up.  Coarse 
particles  could  be  readily  seen  in  the  mixture. 
A  second  sample,  prepared  by  adding  the  lime  water  in  small 
amounts  and  triturating  after  each  addition  till  a  perfect  magma 
was  formed,  had  scarcely  commenced  to  precipitate  five  minutes 
after  being  shaken.  The  particles  were  apparently  evenly  divided, 
and  after  final  separation,  on  long  standing,  the  precipitate  was 
twice  as  bulky  as  that  in  the  first  specimen.  It  is  easy  to  imagine 
which  sample  could  be  most  evenly  applied  and  would  give  the 
most  benefit  when  applied  to  the  skin. 
The  following  formula  presents  a  unique  difficulty : 
$ 
Kaolini   .   oz.  4. 
Glycerini   fl.  oz.  1. 
Sod  Salicylatis    dr.  2. 
Ol.   Eucalypti   fl.  dr.  4. 
Ac.  Borici   gr.  50. 
01.  Gaultherias   fl.  dr.  2. 
Mentholis    gr.  40. 
Lanolmi    oz.  2. 
M 
This  was  prepared  by  rubbing  the  Kaolin,  Boric  Acid,  Sodium 
Salicylate  and  Lanolin  together  in  a  mortar,  incorporating  the 
Oils  in  which  the  Menthol  had  been  dissolved,  and,  finally,  adding 
the  Glycerin.  The  result  was  a  granular  mass  mixed  with  what 
appeared  to  be  streaks  of  oil.    However,  the  oils  had  been  per- 
