68 
Medicated  Waters. 
Am.  Jour.  Pharm. 
Feb.,  1884. 
inodorous  bodies,  which  ma)'  or  may  not  be  soluble.  This  view  is  a 
plausible  one  when  we  consider  the  delicate  chemical  constitution  of  the 
oils  in  general,  especially  those  containing  the  previously  mentioned 
compounds.  Upon  this  fact  may  be  based  the  superiority  of  "  Dis- 
tilled" over  "Triturated"  waters,  as  in  distillation  the  water  is  impreg- 
nated with  the  oil  direct  and  unchanged ;  while  in  trituration,  if 
performed  with  carbonates,  some  changes  undoubtedly  ensue,  since  the 
products  from  the-  latter  process  are  of  less  fine  qualities  than  those  of 
the  former;  although  both  may  be  made  from  the  same  oil.  It  is 
absolutely  necessary  on  this  account,  to  use  a  body  free  from  these 
objectionable  features  and  one  which  has  all  the  essential  requisites  in 
the  greatest  degree.  After  numerous  trials  I  have  found  precipitated 
calcium  phosphate  to  possess  all  the  desired  properties  and  to  yield 
products  that  were  in  all  respects  the  equal  of  those  obtained  by  dis- 
tillation. 
This  lime  salt  is  a  neutral,  impalpable  solid,  wholly  insoluble  in 
water,  neutral  or  carbonated,  and  when  used  permits  filtration  much 
more  readily  and  effectively  than  any  other  medium.  In  diffusive 
power  it  is  fully  the  equal  of  any  of  the  bodies  previously  mentioned ; 
leaving  nothing  to  be  desired.  Before  its  use,  although  generally  very 
pure,  tests  should  be  always  applied  to  determine  that  fact.  It  should 
be  wholly  soluble  in  dilute  hydrochloric  acid  without  effervescence 
(absence  of  carbonates).  Its  washings  with  distilled  water  should 
yield  no  opalescence  or  precipitate  with  test  solutions  of  silver  nitrate 
(absence  of  chlorides),  barium  chloride  (absence  of  sulphates)  or  ammo- 
nium oxalate  (absence  of  soluble  lime  salts). 
When  diffusive  agents  are  used,  they  require  long  and  persistent 
trituration  with  the  oil  to  effect  thorough  and  minute  subdivision.  In 
order  to  promote  this  diffusion,  a  plan  of  diluting  the  oil  with  a  small 
quantity  of  alcohol  was  tried  and  found  to  work  admirably.  The 
presumed  presence  of  alcohol  in  medicated  waters  thus  made,  has  no 
foundation  in  fact,  if  the  directions  in  the  general  formula,  hereinafter 
given,  are  followed,  as  the  rubbing  to  dryness,  necessarily  volatilizes 
the  whole  of  it. 
General  Formula. — "Triturate,  in  a  mortar  of  broad  surface,  the  oil 
dissolved  in  the  alcohol,  with  the  precipitated  calcium  phosphate,  until 
a  dry  powder  is  secured  and  all  the  alcohol  has  volatilized,  then  add 
the  water  in  small  portions  at  a  time,  stirring  after  each  addition,  until 
the  intended  quantity  to  be  made  is  completed.  Lastly,  filter ;  return- 
ing to  the  filter  the  first  portions,  if  cloudy." 
