^VaTris^so*'"^}   Preparation  of  Mercurial  Ointment,  139 
1.  Reinsch  proposed  i  part  of  turpentine  and  a  little  alcohol  to 
parts  of  mercury.    The  turpentine  is  contrary  to  the  directions  of  the 
German  Pharmacopoeia  ;  his  method  of  extinguishment  yields  satisfac- 
tory results,  especially  if  absolute  alcohol  is  used. 
2.  Heusler  adds  ether.  Ether,  petroleum  naphtha,  chloroform,  etc., 
aid  momentarily  in  dividing  the  mercury;  as  the  evaporation  continues,, 
almost  all  the  mercury  separates  again. 
3.  Reinige  employs  steam  power,  and  adds  sulphuretted  oil  of  tur- 
pentine. 1  agree  with  him  in  using  steam-power,  but  consider  the 
addition  unsuitable,  and  therefore  did  not  test  its  efficacy. 
4.  Loewel  attaches  a  mixture  of  olive  oil  and  mercury  to  the  saw  of 
a  saw-mill,  and  extinguishes  by  shaking.  This  process  is  recom- 
mended  by  many,  but  seems  unsuitable  for  making  large  quantities^ 
1,  like  most  others,  had  no  facilities  to  test  this  method. 
5.  Luederson  states  that  a  darker  colored  ointment  is  abtained  by 
.  long-continued  trituration,  caused,  in  his  opinion,  by  the  formation  of 
black  oxide.  I  consider  this  correct  as  far  as  the  color  is  concerned, 
but  do  not  believe  in  his  explanation,  since  I  always  obtain  the  dark 
colored  ointment  by  triturating  with  steam-power  for  5  or  6  hours,  in 
which  short  time  a  formation  of  black  oxide  seems  impossible. 
6.  Guibourt  mentions  I'7I5  as  the  specific  gravity  of  an  ointment 
made  in  the  proportion  of  i  to  2,  while  Buchner  found  it  to  be  1*330. 
Hager  agrees  with  the  latter,  while  I  found  it  to  be  1*32  to  1*34. 
7.  Heauly  suggests  in  the  place  of  the  saltpetre,  which  was  recom- 
mended by  Polmonte,  an  addition  of  6  parts  of  potassium  sulphate  to 
500  parts  of  mercury.     Both  plans  were  not  tried  by  me. 
8.  Mouchon  adds  one-fifth  stearic  acid,  which  1  tried  without 
success. 
9-  Snoep  recommended  boiling  the  fatty  matter  to  be  used  for  some 
time  with  water,  then  dehydrating  it,  and  claims  to  have  obtained 
usually  favorable  results.  The  process  was  not  satisfactory  in  my 
hands. 
10.  Coldefier  spreads  500  grams  of  lard  under  a  bell-glass,  in  a  thin 
layer,  so  as  to  increase  its  surface,  and  then  suspends  above  t  a  piece 
of  phosphorus  for  15  days  ;  the  ozonized  lard  is  then  transferred  to  a 
wide-mouthed  bottle,  250  grams  (^f  mercury  are  added,  and  heat  is 
applied  until  the  lard  begins  to  flow,  when  the  mixture  is  well  shaken 
for  some  time,  and  the  ointment  is  finished  by  quickly  cooling  with 
immersion  in  cold  water.    I  made  use  of  the  first  portion  of  this  sug- 
