196 
PILLS  AND  EXCIPIENTS  FOR  THEM. 
quest  of  some  medical  friends  that  the  few  hints  here  appended 
are  offered  to  your  readers  to  assist  them  in  this  matter. 
An  excipient  should  be  harmless  and  tenacious  during  the 
ordinary  changes  of  heat  and  moisture  ;  should  remain  soluble, 
even  when  mixed  with  those  substances  likely  to  harden  it,  and 
withal  be  therapeutically,  as  well  as  pharmaceutically,  compatible 
with  the  remedies  it  is  associated  with. 
In  view  of  these  requirements,  gums  arabic  and  tragacanth  are 
both  obnoxious  to  criticism,  although  they  can  and  are  used  suc- 
cessfully to  make  the  masses  cohere,  in  a  short  time  they  become 
so  hard  that  they  render  many  pills  almost  insoluble,  and  when- 
ever a  pill  mass  can  be  formed  without  the  use  of  either  of  them 
they  should  not  be  employed. 
One  of  the  most  desirable  excipients  for  substances  which  are 
not  liable  to  be  deoxidized  or  reduced,  is  made  by  evaporating 
clear  honey  to  about  one-half  its  bulk.  When  thus  treated  honey 
is  very  tenacious,  and  yet  is  very  readily  miscible  with  the 
juices  of  the  stomach  ;  when  used  in  the  proportion  of  one  grain 
to  three  of  sulphate  of  quinine  the  mass  is  sufficiently  firm  for 
making  pills  which,  without  any  acid,  are  smaller  than  those  made 
in  accordance  with  directions  of  the  pharmacopoeia. 
Ferrum  redactum  is  very  advantageously  made  with  this  ex- 
cipient, great  care  being  exercised  lest  any  excess  be  used,  as 
the  great  density  of  mass  renders  the  pills  very  liable  to  flatten 
before  becoming  dry  enough  to  dispense.  The  subnitrate  and 
subcarbonate  of  bismuth  are  also  very  elegantly  made  with  this 
material,  the  same  care  being  taken  to  avoid  any  excess  and  for 
the  same  reason. 
Another  excipient  of  this  kind,  and  which  remains  soluble  for 
almost  any  length  of  time,  is  glycerin,  in  which  one-twenty-fifth 
part  of  its  weight  of  finely  dusted  white  tragacanth  gum  has  been 
mixed;  this  material  was  first  suggested  to  me  by  Dr.  J.  0.  Leamyof 
Baltimore,  Md.  After  the  tragacanth  has  been  added  it  should 
stand  for  twenty-four  hours,  when  it  will  be  fit  for  use.  Pills 
made  with  this  are  quite  small,  and  it  is  well  adapted  to  such 
masses  as  contain  dessicated  salts  such  as  dried  sulphate  of  iron. 
Another  excipient  which  admits  of  a  wide  range  of  applica- 
tions is  extract  of  gentian ;  its  greatest  adaptation  being  in 
