62 
EMULSIONS  OF  GUM-RESINS  AND  RESINS. 
rapidly  separate,  the  resins  floating  and  uniting  on  the  surface  of 
the  liquid.  But  when,  as  is  frequently  the  case,  we  have  to  pre- 
pare a  mixture  or  injection  containing  any  of  the  gum-resins,  gum 
ammoniacum  or  assafoetida,  for  instance,  or  a  resin,  more  espe- 
cially that  of  tolu,  which  mixes  very  incompletely,  it  is,  I  think,  of 
some  importance  to  obtain  a  more  ready  and  advantageous  pro- 
cess for  their  admixture  than  any  of  those  hitherto  employed  for 
this  purpose.  Among  those  mentioned  in  works  on  Pharmacy  we 
find  the  use  of  mucilage,  or  what  is  preferable,  the  yolk  of  egg; 
but  these  means,  although  very  good  in  themselves,  become  tedi- 
ous when  adopted  in  hospitals,  where,  in  a  short  space  of  time,  a 
large  number  of  mixtures  have  to  be  prepared  ;  and  even  when 
yolk  of  egg  is  used,  the  resins  above  mentioned  are  frequently  but 
imperfectly  mixed. 
Having  frequently  had  occasion  to  see  the  gum-resins  prescribed, 
and  among  them  that  of  assafoetida,  which,  as  is  known,  is  a  very 
energetic  medicine,  I  endeavored  to  find  some  means  of  shortening 
the  process  of  trituration  ;  and  I  think  that  the  process  I  am  about 
to  describe  will  be  a  considerable  saving  in  point  of  time,  and 
also  be  more  efficacious  for  mixing  the  gum-resins  and  even  the 
resins.  The  gum-resins  will,  in  the  first  instance,  claim  attention, 
for  the  remarks  I  have  to  make  on  the  resins  are  but  a  confirma- 
tion of  the  first-named  process. 
Having  been  called  upon  on  several  occasions  to  prepare  mix- 
tures and  injections  in  which  gum  ammoniacum  and  assafoetida 
were  used,  the  following  was  the  method  I  employed  for  their  pre- 
paration : — 
I  place  the  quantity  of  gum-resin  prescribed,  in  small  pieces, 
in  a  marble  or  porcelain  mortar,  and  add  about  four  times  its 
weight  of  alcohol.  I  then  ignite  the  alcohol  and  triturate  the 
whole  with  a  porcelain  pestle  until  the  alcohol  has  all  burned 
away.  The  gum-resin  acquires  the  appearance  of  a  soft  extract. 
The  liquid  is  now  added  in  small  quantities  at  a  time,  and  a  per- 
fectly homogeneous  emulsion  is  produced,  from  which  no  separation 
takes  place  on  standing,  and  in  which  the  gum-resin  is  very  com- 
pletely distributed,  a  result  which  it  is  difficult  to  ensure  when 
yolk  of  egg  is  used,  even  after  long  trituration.  In  this  way  the 
guru-resin  is  presented  to  the  absorbent  surfaces  of  the  stomach 
