Am/u(J^-1f£arm-}  Paraffin  as  an  Excipient  341 
chlorine,  or  48'68  per  cent,  of  that  incorporated  in  the  mass  as  hy- 
drogen chlor-aurate.  These  results  prove  the  presence  of  a  consider- 
able amount  of  free  hydrochloric  acid  in  the  mass,  as  the  amount 
of  chlorine  dissolved  out  as  gold  salt  (HAuCl44H20),  and  therefore 
part  of  the  total  48 '68  per  cent,  found,  is  only  equal  to  '021993  gm. 
or  15*94  per  cent,  of  the  total  originally  combined  with  the  excipient 
as  hydrogen  chlor-aurate.  Whether  the  15*32  per  cent,  of  chlorine 
which  remains  unaccounted  for,  had  combined  to  form  additive  or 
substitution  products  with  the  olefins  probably  contained  in  the 
mixed  paraffins,  or  whether  it  was  altogether  dissipated,  has  not  yet 
been  ascertained.  The  mode  of  its  disappearance,  while  not  essential 
to  the  purpose  of  the  preceding  inquiry,  yet  remains  of  some  interest 
from  a  chemical  point  of  view. 
The  conclusions  to  be  drawn  from  the  investigations  mentioned  in 
this  paper,  and  those  published  July  12,  1884,  are  that  Martindale's 
mass  may  be  pronounced  perfect  as  an  excipient  for  silver  salts,  of 
which  argentic  nitrate  may  be  cited  as  a  type.1  Practically,  it  can 
also  be  said  to  answer  its  purposes  for  permanganate  of  potassium, 
particularly  if  the  pills  are  recently  dispensed  with  a  minimum  quan- 
tity of  excipient.  That  it  appears  to  fail  somewhat  conspicuously  in 
the  unstable  chlorine  compounds  of  gold  is  probably  due  to  the  rela- 
tively large  quantities  of  the  excipient  used,  viz.:  12  parts  of 
excipient  to  1  of  sodium  chlor-aurate,  and  18  to  1  of  hydrogen  chlor- 
aurate.  With  a  little  dispensing  ingenuity  the  total  quantity  re- 
quired could  be  considerably  decreased,  thus  probably  increasing  the 
available  percentage  of  unreduced  salt  in  the  pills,  which  should  al- 
ways be  made  up  only  as  required  for  use.  Those  who  can  recall  to 
memory  the  unsatisfactory  methods  of  dispensing  the  unstable  com- 
pounds mentioned  in  this  paper  before  Mr.  Martindale  suggested  the 
excipient  which  now  bears  his  name,  will  readily  admit  that  the  thanks 
of  all  dispensers  and  therapeutists  who  have  to  deal  with  them  are 
due  to  that  gentleman  for  his  scientific  foresight  and  generosity  in  ad- 
vocating and  publishing  formulae  for  general  use  on  the  dispensing 
counter.  The  excipient  is  not  yet  perfect,  however,  but  the  dispenser 
may  not  have  long  to  wait  before  the,  difficulty  which  is  at  present 
experienced  in  purifying  the  commercial  paraffin  compounds  from  a 
series  of  lower  homologues  will  be  overcome. — Phar.  Jour,  and 
Trans.,  May  15,  p.  957-958. 
^ee  Pharmaceutical  Journal  for  July  12, 1884,  p.  21.  Am.  Jour.  Phar.  1884,  p.  437 
