250  ON  PILULJ3. 
make  only  on  the  small  scale,  to  those  who  use  them  in  dispensing, 
and  to  those  who  swallow  the  pills. 
Unfortunately,  those  who  make  pills,  especially  the  wholesale 
makers,  rarely  have  the  opportunity  of  examining  the  condition 
of  their  workmanship  after  it  has  stood  the  test  of  a  few  weeks 
or  months'  keeping  in  the  hands  of  the  patient.  The  skilful 
dispenser  who  prides  himself  upon  his  accuracy  and  care,  would 
often  be  ashamed  of  his  work  if  he  could  see  it  a  few  weeks  old. 
A  series  of  experiments  which  I  tried  some  time  since,  though 
designed  to  yield  information  to  be  used  in  dispensing,  elicited 
a  few  facts  which  may  usefully  aid  our  present  purpose. 
A  variety  of  medicines  were  made  into  pills  with  treacle,  soft 
soap,  conserve  of  roses,  and  glycerine.  After  a  few  months' 
keeping,  an  examination  showed  that  those  prepared  with  glyce- 
rine had  most  effectually  retained  their  soft  condition. 
A  specimen  of  Pulvis  Pilulae  Rhei  Composite  (prepared  ac- 
cording to  the  London  Pharmacopoeia,  but  using  powdered  soap 
instead  of  soft  soap,  and  omitting  the  treacle)  made  into  a  mass 
with  glycerine  was,  while  new,  rather  deficient  in  tenacity,  but 
became  tough  on  keeping  for  a  few  weeks,  and  retained  its  tough- 
ness for  several  months.  A  specimen  of  the  same,  made  into  a 
mass  with  treacle,  was  tough  while  new,  but  by  keeping  became 
crumbly. 
Other  medicines  which  have  not  adhesiveness  in  themselves 
may  be  made  into  a  good  mass  with  a  mucilage  of  the  following 
composition  :-— 
Powdered  Tragacanth  3iij. 
Glycerine,  f^ix. 
Mix  and  add  Water,  giv. 
Prof.  Redwood,  in  his  Practical  Pharmacy,  says  "  the  indis- 
criminate use  of  tragacanth  cannot  be  too  strongly  condemned  ;" 
he  might  have  added  that,  if  judiciously  applied,  there  are  few 
substances  so  generally  useful  for  imparting  tenacity,  or  over- 
coming the  inconvenience  of  hygroscopic  extracts,  &c.  For  the 
former  purpose  its  union  with  glycerine  prevents  it  giving  an 
undue  hardness  and  insolubility,  and  for  the  latter  purpose  it  is 
necessary  only  to  use  it  in  the  smallest  effectual  proportion. 
Thus  blue  pills  frequently  have  an  inconvenient  stickiness,  which 
is  effectually  removed  by  the  addition  of  twenty  grains  of  pow- 
