^Mayr;Swrm'}     Practical  Remarks  on  Pearl  Coating.  241 
ing  n  and  "discoloration/'  and  to  each  of  these  a  word.  I  have  made 
a  distinction  between  pitting  and  falling,  as  I  look  upon  them  as  dif- 
ferent troubles  proceeding  from  distinct  causes.  Pitting  gives  the  pills 
all  the  appearance  of  dried  peas,  while  falling  simply  flattens  them  on 
the  point  of  the  rest.  Pitting  in  its  worst  form,  I  think,  occurs  in  the 
compound  colocynth  pill,  and  therefore  it  may  be  taken  as  typical.  It 
is  generally  ascribed  to  the  resin  of  scammony,  and,  certainly,  since  the 
resin  has  been  substituted  for  scammony  the  evil  has  increased.  Still, 
other  pills  containing  no  resin  of  scammony  undoubtedly  pit  also,  and, 
therefore,  I  am  inclined  to  look  upon  it  more  as  an  aggravating  cause. 
As  a  rule,  it  will  be  found  that  all  pills  containing  aloes,  resins  or  gum 
resins  in  excess  have  a  tendency  under  certain  circumstances  to  pit. 
What  are  these  circumstances?  A  theory  was  given  me  the  other  day 
which  I  may  here  throw  out,  although  I  have  had  no  opportunity  of 
verifying  it.  If  the  essential  oil  be  added  to  the  resin  of  scammouy 
(reverting  to  the  colocynth  pill)  before  all  the  ingredients  forming  the 
mass  are  mixed — in  other  words,  if  the  ingredients  are  thrown  separ- 
ately into  a  mortar  and  the  oil  of  cloves  added  before  mixing,  the 
probability  is  that  the  oil  might  come  in  direct  contact  with  the  resin, 
and  would,  in  some  way,  act  upon  it  so  as  to  change  its  physical  prop- 
erties, and  prevent  it  again  immediately  hardening.  There  is  this  to 
support  the  theory,  that  even  with  the  same  ingredients  the  mass  at 
different  times  exhibits  different  properties  directly  affecting  the  pill. 
This,  in  my  experience,  applies  not  only  to  the  colocynth  pill  mass, 
but  to  others,  also,  which  pit  more  or  less  on  keeping.  A  soft  aloes 
or  a  soft  resin  or  gum  to  begin  with,  andean  overworking  of  the  mass, 
either  with  the  pestle  or  the  hands,  produce  very  much  the  same  re- 
sults. In  the  case  of  the  colocynth  pill,  if  soap  is  substituted  for  sul- 
phate of  potash  the  tendency  to  pit  is  greatly  lessened.  I  am  no  advo- 
cate for  tampering  with  officinal  formulae,  but  sulphate  of  potash  is 
really  not  required  in  the  present  pill,  while  soap,  to  my  mind,  is  in 
every  way  an  improvement. 
Add  to  this  suggestion  a  little  care  in  securing  hard  dry  aloes  and 
resin  of  scammony,  and  also  in  forming  a  mass  neither  too  hard  nor 
too  soft,  and  the  trouble  should  be  reduced  to  a  minimum. 
Falling  will  occur  in  almost  any  pill  if  made  too  soft,  but  I  refer  at 
present  to  falling  from  one  peculiar  cause,  not  generally  noticed,  name- 
ly friction.  If  you  want  a  colocynth  pill  that  will  fall,  use  the  rounder 
or  finisher  with  all  your  might.    Pills  that  require  to  be  coated,  re- 
16 
