242  Practical  Remarks  on  Pearl  Coating.     { Am^°auyr;  g£7arm- 
quire  to  be  dry  and  hard.  Of  course  they  are  rounded  from  time  to 
time,  each  time  probably  as  they  get  harder  -with  increased  friction, 
and  so  the  mischief  is  done.  In  a  short  time  the  pills  assume  all  forms 
as  if  they  were  not  on  good  terms  with  each  other.  I  have  always 
attributed  the  peculiarity  to  the  heat  produced  by  the  friction,  and  the 
cure  is  a  little  more  care  in  finishing,  so  as  not  to  require  too  much  of 
the  rounder,  and  a  little  attention  to  frequent  shaking  during  the  pro- 
cess of  drying. 
Discoloration  however,  is  probably  the  most  fertile  cause  of  annoy- 
ance to  be  met  with  in  pearl-coating,  and  as  you  know  the  predisposing 
causes  to  discoloration,  I  need  not  dwell  upon  them.  As  I  have  al- 
ready said,  I  am  no  advocate  for  substitution  in  officinal  formulae,  but 
the  difficulty  must  be  bridged  over.  Fortunately  it  is  here  if  any- 
where that  the  pharmacist  stands  strongest.  He  does  not  require  to 
stock  his  pills  for  twelve  months,  or  even  for  six  months.  He  has 
only  to  stick  to  the  proper  formulae,  dry  them  in  the  usual  manner, 
coat  them,  and  see  how  long  they  will  keep,  and  prepare  his  stock  ac- 
cordingly. This  is  troublesome.  Of  course  it  is,  but  we  need  not  ex- 
pect to  get  any  great  good  in  this  world  without  trouble.  I  would 
much  prefer  myself  to  mass  comp.  rhubarb  pill  with  water  rather  than 
glycerin,  and  do  many  other  things  not  directed  in  the  Pharmacopoeia, 
but  I  do  not  see  any  change  which  I  can  make  in  this  direction  that 
would  not  in  the  end  be  to  my  own  prejudice.  I  know  some  laugh  at 
the  idea  of  pills  losing  any  of  their  active  properties  by  the  process  of 
hardening,  but  I  have  proofs  too  abundant  to  doubt  the  fact  for  one 
moment.  In  the  majority  of  cases  the  loss  may  not  be  noticed,  but 
take  an  active  cathartic  pill  such  as  the  colocynth,  and  its  action  is  not 
only  greatly  retarded,  but  also  very  much  impaired. 
The  drying  of  pills  must  always  be  looked  upon  as  one  of  the  ni<  st 
important  parts  of  the  process.  I  have  tried  various  plans,  but  have 
always  come  back  to  the  old  plan  of  drying  on  trays  in  a  dry  room. 
The  pills  are  ready  for  coating  whenever  thoroughly  dry  on  the 
outer  surface,  and  while  still  a  little  soft  towards  the  centre.  In  this 
state  they  will  not  keep  long,  but  they  will  retain  their  maximum  of 
activity. 
In  connection  with  the  subject,  I  may  mention  that  a  gentleman, 
I  believe  known  to  you  all  (Mr.  W.  L.  Howie),  the^end  of  last  year 
worked  out  a  process  of  giving  to  pearl-coated  pills^the  character  and 
sweetness  of  sugar  by  the  use  of  Fahlberg's  coal  tar  saccharin.    I  have 
