340 
Paraffin  as  an  Excipient 
/  Am.  Jour.  Phaim. 
\       July,  1886. 
cent,  had  therefore  taken  place.  Owing  to  an  accident  to  the  filtrate 
the  chlorine  was  not  estimated. 
Estimation  of  unreduced  salt  in  a  pill-mass  containing  acid  chloride 
of  gold  (hydrogen  chlor-aurate). — In  the  gold  and  chlorine  estimation, 
•3605  gm.  of  salt  was  used.  The  modus  operandi  in  this  case  was 
similar  to  the  preceding  estimation  of  the  sodium  chlor-aurate,  and  a 
total  yield  of  "174  gm.  metallic  gold  and  '503  gm.  argentic  chloride 
was  obtained.  The  percentage  results  calculated  for  HAuCl4.4H20 
agree  well  with  theory  : — 
Calculated.  Found. 
H=  -24 
Au  =  47'8   48-266 
01  =  34-46  345 
4(H20)=17-5 
100-00 
In  making  the  pill-mass,  the  following  formulae  were  used,  having 
regard  to  the  probable  dose  (l-30th  to  l-20th  of  a  grain): — 
(Hypothetical  Prescription.) 
R  Auri  perchloridi  (acidi)  gr.  4$. 
Excipientis  (Martindale)  q.  s. 
Fiat  pilula  secundum  artem.    Mitte  20. 
( Working  Formula.) 
Acid  chloride  of  gold  1  part. 
Paraffin  wax  3  parts. 
White  vaseline  6  parts. 
Washed  kaolin  9  parts. 
The  mode  of  mixing  was  the  same  as  in  the  preceding  case.  One 
part  of  salt  is  contained  in  19  of  mass,  so  that  19  grains  of  the  latter 
would  make  twenty  pills,  containing  l-20th  of  a  grain  in  each.  The 
mass  itself  was  made  June  3,  1885,  and  estimated  January  13,  1886. 
It  had  been  kept,  therefore,  about  seven  and  a  half  months  (two  hun- 
dred and  twenty-four  days).  7*6015  gm.  of  mass  were  taken  for 
analysis,  equivalent  to  *4  gm.  of  the  salt  (HAuCl4.4H20).  The 
treatment  was  similar  to  that  of  the  preceding  sodium  chlor-aurate 
pill-mass,  and  the  total  weights  of  precipitated  metallic  gold  and 
silver  chloride  obtained  were  '0305  gm.  and  *2715  gm.  respectively. 
The  gold  found  ('0305  gm.)  is  only  equivalent  to  *0638  gm. 
(HAuCl44H20)  or  15*95  per  cent,  of  that  actually  incorporated  in 
the  mass.  The  reduction  (84  per  cent.)  is  considerably  more  than 
was  expected  from  the  appearance  of  the  mass  before  estimation. 
The  silver  chloride  found  (*2715  gm.)  is  equivalent  to  '06713  gm.  of 
