A%p°r,iir;i?oh6arm'}  Liquor  Cresolis  Compositus.  171 
would  be  required  for  the  completion  of  the  reaction,  if  one  there 
was,  and  it  was  found  that  the  sample  which  was  at  first  quite  turbid 
and  which  made  a  very  milky  mixture  when  poured  into  water,  be- 
came gradually  clearer,  and  produced  less  and  less  milkiness  when 
added  to  water,  but  that  the  time  for  the  completion  of  the  prep- 
aration was  three  weeks.  Another  experiment  was  made  later, 
again  testing  from  day  to  day,  and  it  was  found  that  this  time  it 
required  two  weeks  and  five  days  for  the  production  of  a  soluble 
preparation. 
Samples  of  the  solution  were  then  made  up,  using  the  official 
proportions  of  all  of  the  ingredients,  but  altering  the  working  for- 
mula so  as  to  complete  the  reaction  between  the  linseed  oil  and  the 
potassium  hydroxide  before  adding  the  cresol. 
This  modification  of  the  formula  was  found  to  answer  perfectly 
for  producing  a  preparation  which  is  transparent  as  soon  as  com- 
pleted, and  which  mixes  clear  with  all  proportions  of  water  without 
any  delay  whatever.  The  actual  working  process  is  as  follows  : — 
A  soft  soap  is  first  prepared,  using  the  same  amounts  of  linseed 
oil  and  potassium  hydroxide  as  directed  for  the  preparation  of  the 
official  compound  solution  of  cresol.  The  details  of  the  process, 
on  the  small  scale  may  be  the  same  as  that  directed  for  the  U.  S.  P. 
soft  soap. 
Heat  the  linseed  oil  (350  grammes)  in  a  deep  capacious  vessel, 
on  a  water  bath,  to  a  temperature  of  about  700  C.  Dissolve  the 
potassium  hydroxide  (80  grammes)  in  450  cc.  of  water,  warm  the 
solution  to  about  700  C,  add  it  to  the  linseed  oil  and  mix  thoroughly. 
Then  incorporate  40  cc.  of  alcohol  and  continue  the  heat  with- 
out stirring  until  a  small  portion  of  the  mixture  is  found  to  be 
soluble  in  boiling  water  without  the  separation  of  oily  drops.  The 
soap,  thus  prepared,  is  now  dissolved  in  500  grammes  of  cresol  and 
a  sufficient  quantity  of  water  added  to  make  the  solution  weigh 
1000  grammes. 
This  solution  may  be  immediately  mixed  with  water,  in  any  pro- 
portion, forming  a  clear  liquid,  and  will  correspond  with  the  official 
solution  in  strength  and  content. 
Other  suggestions  have  been  made  for  the  extemporaneous  prep- 
aration of  this  solution,  such  as  the  replacing  of  the  linseed  oil  by 
a  more  readily  saponifiable  oil,  as  cotton-seed  oil,  but  as  this  would 
modify  the  preparation  to  the  extent  of  changing  the  soap  and 
