240  Practical  Remarks  on  Pearl  Coating.  {Am-^;^xm- 
volves  a  new  departure  from  the  modern  tendency  and  spirit  of  the 
Pharmacopoeia.  Every  recent  change  in  the  formulae  for  "  pilulse  " 
has  been  in  the  direction  of  producing  a  mass  at  once  firm  and  plastic, 
and  which  would  at  the  same  time  prevent  the  pills  from  getting  too 
hard  on  keeping.  Now  the  only  element  of  success  in  pearl-coating, 
so  far  as  my  experience  goes,  is  to  have  a  hard  dry  pill  to  begin  with. 
Beyond  this  and  a  little  common  sense  to  adapt  quantities,  and  a  little 
muscular  exertion,  there  is  nothing  about  the  process  which  a  child 
could  not  perform.  But  notice  how  the  condition  of  hardness  and  dry- 
ness just  mentioned  agrees  with  the  officinal  formula?.  In  the  Pharma- 
copoeia, there  are  in  all,  I  think,  twenty-one  different  li  pilulse,"  and 
of  these  fully  one  half  contain  ingredients  which  are  utterly  incom- 
patible with  pearl -coating.  There  are,  for  example,  seven  different 
masses  made  with  such  hygroscopic  substances  as  glycerin  and  trea- 
cle ;  there  are  other  four  containing  essential  oils  and  other  elements 
equally  unworkable,  and  I  venture  to  say  that  no  human  ingenuity 
will  pearl-coat  the  pills  made  from  such  masses,  and  at  the  same  time 
adhere  both  to  the  letter  and  spirit  of  the  Pharmacopoeia,  But  if 
Mahomet  does  not  go  to  the  mountain,  the  mountain  must  go  to  Ma- 
homet, and  so  the  difficulty  has  been  bridged  over — But  how? 
A  second  point  which  I  would  notice  is  the  amount  of  French  chalk 
required  in  this  process.  From  a  series  of  experiments  which  I  have 
made,  I  find  the  amount  required  ranges  from  twenty  to  thirty  per 
cent,  of  the  weight  of  the  pills  coated.  This  makes  a  considerable  in- 
crease both  in  the  size  and  weight  of  the  old  5  grain  pill,  and  suggests, 
by  the  way,  an  increase  in  the  size  of  the  pill  boxes  in  general  use. 
It  is  not  for  me  to  say  what  the  physiological  effects  of  fifteen  or  twen- 
ty grains  of  an  insoluble  silicate  per  day  may  be  on  the  human  economy, 
particularly  if  continued  for  a  length  of  time,  as  in  the  case  of  Blaud^s 
pills,  but  it  at  least  suggests  the  careful  examination  of  the  chalk  used, 
in  case  of  its  contamination  with  any  deleterious  substance.  This  large 
amount  of  chalk  may  be  increased  at  pleasure.  If  the  liquid  with 
which  the  the  pills  are  damped  be  too  thick,  or  if  too  much  be  added, 
more  chalk  will  be  required,  and  the  pills  will  be  heavier  and  larger. 
Even  ten  per  cent,  of  an  increase  by  weight  of  chalk  is  not  a  bad  profit 
were  we  to  sell  the  pills  by  weight,  but  as  we  only  retail  them  by  num- 
ber the  hint  is  probably  thrown  away. 
The  three  great  difficulties  which  pharmacists  will,  however,  probably 
require  to  face  as  regards  successful  pearl-coating,  are  "  pitting,"  "fall- 
