AM.  jouK.  PH.KM.  1         Liquor  Plumbi  Suhacetatis.  249 
June  1,  1871. 
filtration  of  tlie  small  quantity  of  undissolved  basic  acetate,  a  clear 
liquid,  which,  however,  after  several  days,  deposited  a  slight  precipi- 
tate. The  specific  gravity  was  found  to  be  1-238,  and  19-3255  grms. 
of  the  liquid  gave,  when  precipitated  with  sulphuric  acid,  and  after 
the  expulsion  of  the  liberated  acetic  acid,  by  evaporation,  5-0258 
grms.  sulphate  lead,  equal  to  19*14  per  cent,  of  oxide  of  lead. 
3.  The  Bavarian  Pharmacopoeia  takes,  for  three  parts  of  acetate  of 
lead,  one  part  of  litharge  and  eight  parts  of  water,  and  boils  down  the 
mixture  till  the  liquid  has  acquired  a  specific  gravity  of  1-360.  Ac- 
cording to  Wittstein  (Chemisch-Pharmaceutische  Praeparate)  it  is 
easier  and  better,  and  yielding  the  same  result,  to  take  only  one 
half  the  quantit}^  of  water.  My  experiment  was  made  according  to 
Wittstein,  and  18  grms.  of  acetate  of  lead,  with  6  grms.  of  oxide 
of  lead,  were  digested  with  33  grms.  of  water,  and,  after  filtration, 
gave  a  clear  liquid  of  1*376  specific  gravity.  12*5856  grms.  gave 
4*8464  grms.  sulphate  of  lead,  equal  to  28*34  per  cent,  of  oxide  of 
lead. 
4.  The  Pharmacopoeia  Gallica  uses  the  same  proportions  of  acetate 
and  oxide  of  lead  as  the  Bavarian  ;  hence  I  did  not  deem  it  necessary 
to  repeat  my  experiments  with  these  proportions. 
5.  The  Pharmacopoeia  Brittanica  prepares  the  liquor  plumbi  suha- 
cetatis by  taking  5  oz.  (avoird.)  of  acetate  of  lead,  3|-  ounces  of 
litharge,  and  one  imperial  pint  of  distilled  water  ;  boils  for  half  an 
hour,  constantly  stirring  the  mixture  ;  filters  after  cooling,  and  adds 
water  to  make  the  product  20  ounces.    The  specific  gravity  is  1*260. 
In  my  experiment  I  have  taken  20  grms.  of  acetate  of  lead,  14  grms- 
of  litharge  and  60  grms.  of  water,  and  added  to  the  product  the  re- 
quired  quantity  of  w^ater  to  produce  60  grms.  of  liquid.  The  specific 
gravity  in  my  experiment  was  considerably  higher,  and  found  to  be 
1*353.  18  0218  grms.  gave  6*5408  grms.  sulphate  lead,  equal  to 
26*71  per  cent,  of  oxide  of  lead. 
6.  Several  experiments  were  made  with  the  process  recommended  in 
the  U.  S.  Pharmacopoeia,  with  commercial  litharge  as  well  as  with 
chemically  pure  oxide  of  lead,  and,  for  comparison  with  these,  others 
by  using  tlie  cold  process  recommended  by  M.  Nerning  (see  Am. 
Journ.  of  Pharm.,  Sept.,  1870,  p.  467.  Pharm.  Journ.,  July  9th^ 
1870,  from  Journ.  de  Pharmacie  et  de  Chimie.) 
