Ano'ctober,^Km'}        Preparations  in  Powder  Form.  481 
three  together  thoroughly  by  constant  stirring  until  cool.  After 
cooling,  if  any  hard  lumps  are  noticeable  in  the  mixture,  they  should 
be  removed  by  heating,  then  straining  through  a  piece  of  wide  meshed 
cloth,  then  cooled  again  by  constant  stirring.  Now  heat  solutions 
No.  I  and  No.  II  to  just  their  boiling-points  and  quickly  as  possible 
pour  the  two  solutions  simultaneously  into  a  gallon  glass  or  porce- 
lain vessel.  Stir  the  resultant  mixture  vigorously  until  it  becomes 
cool.  The  result  is  a  thick,  soapy,  alcoholic  solution  of  oleo-stearate 
of  pQtash.  Gently  reheat  the  above  solution  to  a  lukewarm  state 
and  to  it  add  2  pints  of  boiling  distilled  water  and  again  mix 
completely  by  vigorous  agitation.  After  a  complete  mixture  is 
obtained,  quickly  as  possible  pour  into  it  the  prepared  solution  of 
zinc  acetate  which  has  been  warmed  to  just  its  boiling-point  and 
thoroughly  stir  this  combined  solution  to  a  uniform  mixture  until 
cool,  which  then  has  a  creamy  consistency.  When  cool,  add  two 
more  pints  of  boiling  distilled  water  and  stir  this  mixture  until  this 
is  also  cool. 
The  solution,  as  prepared  above,  then  contains  the  oleo-stearate 
of  zinc  and  by-products,  which  latter  are  to  be  disregarded. 
To  separate  them,  pour  the  solution  on  a  piece  of  moistened 
draining-cloth  (common  toweling  is  best),  with  close  meshes,  sus- 
pended over  a  vessel  to  catch  the  wash  water.  Collect  the  precipitate 
on  the  cloth  and  return  the  washwater  to  the  drainer  from  time  to 
time  until  it  shows  but  a  slight  turbidity.  Wash  the  precipitate  on 
the  drainer  repeatedly  with  quantities  of  warm  water  until  the 
washwater  is  free  of  all  traces  of  the  acetate  of  potash  and  is  neutral 
to  litmus  paper.  After  neutrality  is  accomplished,  the  cloth  and  its 
contents  are  suspended  in  a  moderately  warm  place,  well  protected 
from  contamination  and  allowed  to  thoroughly  dry.  When  well 
dried  the  mass  is  then  triturated  to  a  fine  impalpable  powder.  The 
powder,  if  carefully  prepared,  has  a  nice,  fluffy,  white  appearance  ; 
smooth,  soft  and  greasy  to  the  touch,  and  possesses  a  pleasant,  bland^ 
fatty  odor,  somewhat  aromatic,  and  neutral  in  reaction. 
In  the  preparation  of  the  oleo-palmitates  the  only  deviation  neces- 
sary in  the  process  is  the  use  ot  450  grains  of  palmitic  acid  instead 
of  the  stearic  acid,  and  the  process  then  followed  out  as  stipulated i 
with  results  corresponding  to  substances  used. 
In  working  with  larger  quantities  than  here  specified,  the  alcohol 
in  the  washwater  may  be  reclaimed  by  adding  sufficient  potassium 
