594 
Pills  and  Excipients. 
(  Am.  Jour.  Pharm., 
1       Dec^  1885. 
of  Pharmacy/^  1870,  page  195,  advocated,  among  other  substances, 
extract  of  gentian  as  a  valuable  material  for  assisting  the  dispenser  of 
pills ;  and,  while  it  is  undoubtedly  excellent  for  very  many  cases,  its 
use  must  not  be  resorted  to  indiscriminately.  All  those  remedies  which 
are  readily  reduced  by  the  glucose,  which  is  contained  in  this  extract 
to  the  extent  of  30  per  cent ,  must  be  massed  with  an  excipient  in 
which  glucose  is  not  present.  This  will  exclude  confection  of  roses, 
honey,  glucose  itself,  and  even  cane  sugar,  as  it  is  changed  by  moisture 
and  the  air. 
The  remedies  which  sliould  never  be  made  with  the  last  named 
substances  are  calomel,  mercurous  iodide,  permanganate  of  potassium, 
oxide  and  nitrate  of  silver,  cupric  oxide,  etc.  The  sample  here  exhib- 
ited of  a  mass  made  with  mercurous  chloride  (calomel)  and  manna, 
only  three  weeks  since,  has  undergone  such  change  as  to  resemble  one 
made  from  mercury  with  chalk.  This  of  itself  is  quite  sufficient 
reason  why  it  should  not  be  used;  but  when  such  a  mass  is  treated 
with  distilled  water  for  a  time,  and  the  clear  liquor  decanted,  liquor 
potassa  communicates  a  pinkish  tinge  and  liquor  ammonia  a  whitish 
cloud,  evidencing  the  presence  of  mercuric  chloride,  a  result  which  is 
necessarily  attended  with  danger.  While  alluding  to  this  change  it 
may  be  worth  while  to  state  that  the  well  known  and  very  valuable 
prescription  of  calomel,  sodium  bicarbonate  and  sugar  will  undergo 
similar  change  by  exposure  to  the  air,  and  hence  the  caution  to  have 
such  powders  frequently  made,  or  only  prepared  when  demanded  by 
the  immediate  occasion. 
It  will  be  found  for  most  of  the  readily  reduced  salts  that  a  mixture 
of  glycerin  in  which  4  per  cent,  of  finely  dusted  tragacanth  has  been 
mixed,  and  kept  for  24  hours  before  use,  is  a  most  admirable  excipient; 
calomel  and  mercurous  iodide  pills  are  thus  very  well  made.  For 
nitrate  of  silver  and  permanganate  of  potassium,  fullers'  earth,  which 
is  principally  silicate  of  alumina,  is  the  most  desirable  substance,  as  any 
organic  matter  has  the  immediate  effect  of  decomposing  the  salts. 
The  following  formulas  will  enable  us  to  overcome  these  difficul- 
ties :  Nitrate  of  silver  gr.  viii,  fullers'  earth  gr.  xvi,  water  q.  s. ;  ft. 
mas. ;  to  be  divided  into  xvi  pills ;  reduce  the  nitrate  of  silver  to 
powder,  add  the  fullers'  earth  and  rub  till  intimately  mixed,  when  the 
water  should  be  added  until  a  good  mass  is  secured.  Potassium 
permanganate  gr.  xvi,  fullers'  earth  gr.  xxiv,  water  q.  s.;  divide  in 
pills  xvi ;  the  permanganate  should  be  powdered  in  a  perfectly  clean 
