Am.  Jour.  Pharm. 
Nov.,  1880. 
Emulsions, 
561 
cient  to  create  suspicion  or  distrust  in  the  mind  of  a  patient,  to  whom 
no  amount  of  explanation  is  satisfactory.  This  is  matter  for  regret 
and  enables  me  to  make  the  observation  that  I  believe  the  blame  for 
much  of  this  can  be  traced  to  a  deficiency  in  pharmaceutical  education, 
for  it  is  a  fact  that  actual  practical  pharmacy — I  mean  the  real  manufac- 
ture  of  preparations  and  practical  use  of  apparatus — forms  no  part  of 
the  curriculum  of  our  school.    The  remedy  suggests  itself. 
The  emulsifying  agents  most  commonly  employed  and  regarded  with 
most  favor  are  the  mucilages  of  tragacanth  and  acacia,  likewise  their 
powders.  My  experiments  have  been  confined  to  these  substances, 
previous  results  having  proven  that  where  honey,  yolk  of  egg  and 
almond  powder  are  recommended  for  special  purposes,  acacia  or  traga- 
canth answers  equally  well  or  better. 
To  decide  the  respective  merits  of  tragacanth  and  acacia  some  forty 
experiments  were  conducted  with  each  gum,  both  in  powder  and  in 
mucilage,  mixed  with  various  oils  and  resins  in  various  proportions,  and 
by  varied  manipulation  the  results  obtained  being  altogether  in  favor  of 
powdered  gum  acacia,  the  emulsions  it  forms  being  perfect  milk-like 
fluids,  in  which  the  eye  cannot  distinguish  any  particle  of  oil  ;  they 
pour  easily  from  the  bottle  and  mix  with  water  in  any  proportion  with- 
out separation.  Most  of  the  forms  given  below  have  been  kept  for 
two  months  and  show  no  deterioration. 
For  general  instructions  when  using  powdered  gum  acacia  it  is  essen- 
tial that  it  be  of  the  best  quality  and  almost  white.  The  substance  to 
be  emulsified,  if.  it  be  a  fluid,  must  be  measured  in  a  dry  measure  and 
poured  into  a  dry  mortar  ;  the  necessary  amount  of  powdered  gum  can 
now  be  well  incorporated,  next  the  portion  of  water  indicated  in  each 
case,  but  by  no  means  let  it  be  measured  in  the  oily  measure.  Now 
stir  well,  taking  care  that  every  particle  of  oil  is  brought  within  range 
of  the  disruptive  mechanical  motion  ;  want  of  attention  to  this  part  of 
the  operation  is  a  frequent  source  of  failure,  for  if  any  oil  gets  up  the 
side  of  the  pestle  or  mortar  and  is  omitted  from  the  emulsifying  process 
it  will  most  certainly  show  itself  by  floating  upon  the  surface  of  the 
finished  product,  spoiling  what  might  otherwise  have  been  a  perfect 
preparation. 
When  the  substance  to  be  emulsified  is  a  solid  or  semi-solid  body 
with  resinous  properties,  it  is  advisable  to  dissolve  it  in  twice  its  quan- 
tity of  rectified  spirit,  then  treat  in  the  same  manner  as  for  fluids. 
36 
