250 
Liquor  Plumbi  Suhacetatis. 
f  Am.  Jour.  Pharm, 
t    June  1, 1871. 
I.  Hot  process.    The  required  specific  gravity  of  the  product  is 
I-  267. 
A.  I  boiled  for  half  an  hour,  16  grms.  of  acetate  of  lead  with  9-5 
grras.  of  litharge  and  64  grms.  of  distilled  water.  The  product  was 
a  clear  liquid  of  1-265  specific  gravity.  9-5588  grms.  gave  2.9403 
grms.  of  sulphate  of  lead,  or  22*64  per  cent,  of  oxide  of  lead. 
B.  The  same  proportions  of  ingredients  were  used,  but  c.  p.  oxide 
of  lead  in  the  place  of  litharge.  The  specific  gravity  of  the  product 
was  1-234.  14-2815  grms.  gave  3-7053  grms.  of  sulphate  of  lead, 
equal  to  19-09  per  cent,  of  oxide  of  lead. 
C.  A  repetition  of  the  last  experiment  with  a  sample  of  acetate  of 
lead  from  another  source,  gave  a  liquid  of  1-230  specific  gravity, 
II-  4528  grms.  of  which  gave  2-9068  grms.  sulphate  of  lead,  equal  to 
18-68  per  cent,  of  oxide  of  lead. 
II.  Cold  process.  The  same  proportions  of  the  requisite  substances 
were  allowed  to  remain,  with  frequent  agitation,  in  contact  for  24 
hours,  and  in  experiment  a.,  made  wiCh  litharge,  gave  a  liquid  of  1-243 
specific  gravity,  of  which  19*3736  grms.  gave  5-2476  grms.  sul- 
phate of  lead,  Avhich  is  equal  to  19'93  per  cent,  of  oxide  of  lead. 
B.  repeated  with  c.  p.  oxide  of  lead,  I  obtained  a  liquid  of  1*242, 
specific  gravity,  of  which  15-2463  grms.  gave  4-1196  grms.  of  sul- 
phate of  lead,  or  19*88  per  cent,  of  oxide  of  lead. 
C.  A  third  experiment,  which  was  made  with  acetate  of  lead  from 
another  source,  yielded  a  liquid  of  1-220  specific  gravity.  13-1400 
grms.  of  the  same  gave  3-2300  grms.  of  sulphate  of  lead,  which  rep- 
resents 18-09  per  cent,  of  oxide  of  lead. 
From  these  experiments  it  will  be  seen  that  the  liquor  plumbi  suh- 
acetatis obtained  by  the  different  Pharmacopoeias  yield  very  different 
products,  but  also  that  the  same  process  gave  products  of  not  exactly 
the  same  composition,  and  as  always  the  same  care  has  been  used  in 
each  case,  I  cannot  account  for  differences  of  nearly  2  per  cent,  in 
the  amount  of  oxide  of  lead  (as  has  -been  found  between  No.  6,  II  A. 
and  C.,)  otherwise  than  that  the  very  low  temperature  at  the  time  of 
the  preparation  of  C.  is  the  cause  of  this  and  other  discrepancies. 
As  a  general  observation  I  will  add,  that  the  preparations  made  in 
the  cold  appear  to  keep  better  than  those  obtained  by  boiling,  the 
latter  more  readily  depositing  basic  salts. 
