58      ON  GLYCELjEUM  :  A  proposed  basis  for  ointments. 
deprived  of  their  oil  by  pressure  and  then  reduced  to  powder, 
answer  equally  well,  though  perhaps  not  all  with  equal  power. 
The  meal  of  decorticated  pressed  sweet  almonds  is  that  which  I 
prefer,  and  which  I  have  used.  Messrs.  Barron,  Harvey  &  Co., 
who  express  a  good  deal  of  almond  oil,  were  kind  enough  to  pre- 
pare for  me  a  cake  of  this  article.  When  powdered,  it  should  be 
passed  through  a  fine  silk  sieve — cypress  or  lawn ;  it  refuses  al- 
together to  go  through  a  fine  wire  sieve. 
To  prepare  Glycelreum  then  : — 
Take  of  Almond  Meal,        .       .    \  oz. 
Glycerin,       .       .        .    1  oz. 
Olive  Oil,  .  .  .  3  oz. 
Mix  s.  a.  It  may  be  effected  in  a  mortar  in  the  ordinary  way 
up  to  nearly  the  end  of  the  operation,  but  it  is  better^  I  think, 
to  use  the  spatula  and  "slice  "  in  the  last  addition  of  oil.  It 
will  then  form  a  soft,  semi-gelatinous  paste,  which,  when  mixed 
gradually  with  water  or  a  watery  fluid,  forms  readily  an  emul- 
sion. The  glycerin  it  contains  being  protected  by  the  oil,  it 
does  not  quickly  deliquesce,  though  when  exposed  to  the  air  for 
some  time  it  does  soften  somewhat.  It  is,  of  course,  unaffected 
by  the  ordinary  temperatures  of  the  body  ;  if  it  were  otherwise, 
its  softness  would  be  an  objection  to  its  use;  as  it  is  it  leaves 
plenty  of  room  for  powdery  admixtures  of  every  kind. 
This  form  may  be  varied  in  many  ways — viz.,  the  glycerin 
may  be  either  pure  or  diluted,  and  mayor  may  not  in  either  case 
contain  medicinal  substances  in  solution.  The  olive  oil  may  be 
substituted  by  another  oil,  or  by  a  mixture  of  oils,  or  again  by  a 
balsam,  an  essential  oil,  or  a  hydro-carbon.  All  these  may  or 
may  not  contain  other  substances  in  solution.  It  is  only  essen- 
tial to  remember  that  the  body,  in  the  first  place,  must  not'pre- 
cipitate  emulsine  ;  in  the  second  place,  must  be  a  fluid.  I  have 
in  several  ways  attempted  to  emulse  lard.  I  have  melted  it  and 
succeeded  perfectly  so  long  as  it  remained  fluid,  but  if  stirred 
after  solidification  the  emulsion  was  at  once  "inverted,"  or,  as 
Mr.  Proctor  styles  it,  converted  into  a  "  negative  "  emulsion, 
i.  e.,  the  glycerin  is  emulsed  in  the  fat,  and  not  the  fat  in  the 
glycerin. 
The  advantages  I  attribute  to  Glycelseum,  as  compared  with 
