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AmjS^iSLarm'}  Paraffin  as  an  Excipient  339 
In  making  the  pill-mass,  the  question  of  doses  (l-30th  to  l-10th  of 
a  grain,  U.S.P.)  had  to  be  considered  in  framing  a  working  formula 
which  would  approximately  represent  what  would  actually  occur  in 
the  pharmacy  if  a  prescription  containing  the  remedy  were  required 
to  be  dispensed.  The  following  formula?  were  adopted  : — 
(Hypothetical  Prescription.) 
R  Auri  et  sodii  chloridi  ....  gr. 
Excipientis  (Martindale)..  q.  s. 
Fiat  pilula  secundum  artem.    Mitte,  30. 
( Working  Formula.) 
Chloride  of  gold  and  sodium  1  part. 
Paraffin  wax  2  parts. 
White  vaseline  4  parts. 
Washed  kaolin   6  parts. 
The  wax  and  vaseline  were  melted  together,  and  the  gold  salt  rub- 
bed down  with  the  kaolin  till  it  was  thoroughly  divided,  then  the 
whole  was  beaten  up  into  a  pill-mass  with  the  requisite  quantity  of 
wax  and  vaseline  mixture.  One  part  of  salt  is  contained  in  every  13 
of  mass,  and  to  dispense  the  above  prescription,  26  grains  of  mass 
would  be  required  for  the  thirty  pills  ordered,  thus  making  each  pill 
weigh  just  under  1  grain.  The  pill-mass  was  made  May  22,  1885, 
according  to  the  above  working  formula,  and  estimated  November  18, 
1885,  consequently  it  had  been  kept  nearly  six  months  (one  hundred 
and  eighty  days).  7*83  gm.  were  weighed  oif  for  estimation,  equal- 
ling -6023  of  incorporated  gold  salt.  The  mass  was  carefully  rubbed 
down  with  distilled  water  at  the  ordinary  laboratory  temperature,  and 
the  resulting  solution  filtered  through  a  long  column  of  moist 
asbestos,  which  had  previously  been  washed  with  HNOs  and  dis- 
tilled water  till  free  from  any  traces  of  chlorine.  By  this  means  all 
the  finely  suspended  kaolin  was  removed  and  the  clear  solution  made 
fit  for  gravimetric  estimation.  The  debris  of  the  pill-mass  (kaolin, 
vaseline,  etc.),  together  with  the  asbestos  filter,  were  washed  with  dis- 
tilled water  till  chlorine  ceased  to  be  detected  in  the  liquid  which 
passed  through.  The  filtrate  was  evaporated  to  a  low  bulk,  and  \ 
gm.  of  oxalic  acid  dissolved  in  a  little  distilled  water  added.  After 
standing  a  few  days,  the  precipitated  metallic  gold  was  collected  on  a 
quantitative  filter,  washed,  dried  and  incinerated.  It  weighed  (less 
ash)  *105  gm.  This  is  equivalent  to  *2205  gm.  of  the  sample  of 
NaAuCl42H20  used,  or  36 '6  per  cent,  of  the  gold  salt,  which  was 
originally  incorporated  in  the  mass.    A  reduction  equal  to  63*4  per 
