54 
ON  SUPPOSITORIES  AND  MEDICATED  PESSAKIES. 
the  suppositories  are  cold,  without  any  fear  of  splitting  them. 
Having  so  far  succeeded,  I  was  tempted  to  return  to  the  clay 
matrix,  with  the  view  of  preparing  a  larger  number  at  a  time 
than  my  metal  mould  was  constructed  for.  The  foil  cones  are 
easily  constructed  so  close  as  not  to  allow  the  escape  of  the 
melted  material,  even  if  they  are  not  imbedded  in  an  impermea- 
ble material ;  the  tinfoil  itself  may  therefore  be  now  considered 
the  mould,  and  the  next  problem  is  to  find  a  convenient  mode  of 
supporting  it  during  the  process.  The  soft  wet  clay  which  I  had 
been  using  was  found  inconvenient,  from  the  foil  adhering  to  the 
clay  so  closely  that  the  suppository  could  not  be  removed  before 
it  was  thoroughly  hard,  and  then  required  to  be  dug  out  as  before 
described.  Trial  was  next  made  with  several  powdered  materi- 
als, such  as  sand,  French  chalk,  or  powdered  clay.  It  is  diffi- 
cult, however,  to  avoid  the  contamination  of  the  suppositories 
with  these  powders,  which  are  all  objectionable,  more  especially 
the  sand,  besides  which,  they  do  not  afford  a  support  to  the 
mould  sufficiently  firm  to  prevent  it  being  bulged  out  of  shape, 
and  they  were  all  in  turn  discarded  ;  clay,  in  its  solid  form,  either 
tough  or  hard,  being  much  more  suitable.  There  is  nothing  more 
simple  than  to  take  a  box  of  clay  and  make  conical  holes  in  it, 
suitable  for  supporting  the  tinfoil  moulds.  I  at  first  used  moist 
clay,  and  kept  it  plastic  by  mixing  with  glycerin,  and  if  the 
shape  of  the  suppositories  is  to  be  changed  from  time  to  time,  the 
plastic  clay  is  most  convenient,  but  if  one  form  is  adopted  for 
general  use,  there  is  no  objection  to  the  clay  matrix  becoming 
Lard,  for  if  it  cracks,  that  is  of  no  importance,  seeing  that  it  is 
only  used  as  a  support  for  the  tinfoil. 
If  the  conical  depressions  are  made  in  moist  clay,  they  are 
most  readily  formed  by  using  a  model  of  a  suppository  as  a  dibble. 
One  hole  made  too  near  another  will  bulge  in  the  sides  of  its 
neighbor,  and  in  that  case  it  is  necessary  to  put  the  dibble  into 
each  a  second  time  after  they  have  all  been  roughly  formed. 
The  model  of  the  suppository  which  is  to  be  used  as  a  dibble, 
and  upon  which  the  tinfoil  moulds  are  to  be  formed,  will  now  re- 
quire a  few  words.  If  the  usual  conical  shape  is  desired,  it  may 
easily  be  extemporized  by  softening  the  end  of  a  rod  of  gutta- 
percha, or  of  a  stick  of  sealing-wax,  and  pressing  it  into  a  conical 
