248 
Liquor  Plumbi  Suhacetatis. 
f  Am.  Jour.  Pharm. 
t    June  1, 1871. 
LIQUOR  PLUMBI  SUBACETATIS. 
By  Stewart  Kellam,  of  Galveston,  Texas. 
(An  Inaugural  Essay.) 
As  it  is  of  considerable  interest  to  tlie  Pharmaceutist  to  know  the 
strength  of  the  basic  acetate  of  lead  of  the  different  Pharmacopoeias, 
I  have,  in  the  laboratory  of  Dr.  F.  A.  Genth,  carefully  prepared  the 
different  samples,  and  have  examined  them  with  reference  to  their 
specific  gravity,  and  the  amount  of  oxide  of  lead  which  they  contain. 
The  materials  used  for  such  preparations  were  first  examined  quali- 
tativel3^  The  acetate  of  lead  was  in  thick,  stout  crystalline  masses  ; 
the  interior  brilliant,  and  only  the  outside  slightly  coated  with  a  more 
basic  acetate  ;  it  was  free  from  copper,  and  contained  no  other  im- 
purities. 
The  litharge,  on  the  contrary,  was  of  far  less  purity.  I  have  exam- 
ined six  samples  from  different  sources  ;  they  all  contained  carbonic 
acid,  and  minute  traces  of  silver  ;  two  of  them  also  metaliclead,  and 
red  oxide  of  lead  ;  two  were  contaminated  with  oxides  of  iron  and 
copper,  with  alumina  and  lime;  and  the  other  two  showed,  besides 
the  impurities  mentioned,  silicic  acid  and  teroxide  of  antimony.  As 
it  is  so  very  easy  to  obtain  the  pure  oxide  of  lead  by  the  calcination 
of  tlie  pure  carbonate,  it  is  advisable  to  prepare  always  the  pure  oxide 
for  pharmaceutical  preparations.  I  have  prepared  my  solutions  of 
the  subacetate,  both  with  the  purest  of  the  examined  samples  of  com- 
mercial litharge,  and  with  chemically  pure  oxide  of  lead. 
1.  Prepared  according  to  the  Pharmacopoeia  Badensis. — 190  parts 
of  sugar  of  lead  are  digested  with  222  parts  of  oxide.  I  have  tried 
the  process  by  digesting,  in  a  close  flask,  12  grms.  of  acetate  of  lead 
with  14  grms.  of  litharge  and  60  c.  c.  of  distilled  water  for  two  days. 
The  mixture,  after  a  short  time,  had  assumed  a  thick,  pasty  consist- 
ence, from  the  formation  of  a  large  percentage  of  the  so-called  \ 
acetate,  and  yielded  such  a  small  proportion  of  liquid  that  further  ex- 
periments were  not  made. 
2.  According  to  the  Prussian  Pharmacopoeia. — 3  parts  of  acetate 
of  lead  are  digested  in  a  close  flask  for  one  or  two  days,  with  1  part 
of  litharge  and  10  parts  of  water,  and  filtering  the  product  after  cool- 
ing, which  then  should  have  a  specific  gravity  of  1'236 — 1'240. 
An  experiment  made  with  18  grms.  acetate  of  lead,  6  grms.  of 
litharge  and  60  c.  c.  of  water  (distilled)  gave,  after  digestion  and 
