A  m.  Jour.  Pharin.  \ 
.November,  1897.  j 
Official  Lead  Preparations. 
571 
One  gramme  of  lead  acetate,  dissolved  in  15  c.c.  of  water  and 
acidulated  with  acetic  acid,  should  require  at  least  26  c.c.  of  decinor- 
mal  potassium  bichromate  solution  for  complete  precipitation  (pres- 
ence of  98  per  cent,  absolute  lead  acetate). 
Special  directions  for  determining  the  end  of  the  reaction  by 
means  of  silver  nitrate  may  also  be  added. 
A  number  of  commercial  samples  of  lead  acetate  were  examined 
in  the  following  manner: 
4  grammes  of  the  salt  were  dissolved  in  sufficient  recently-boiled 
distilled  water  to  measure  40  c.c. 
The  degrees  of  opalescence  of  the  solutions  were  noted. 
10  c.c.  of  the  solution  were  acidulated  with  acetic  acid  and  esti- 
mated by  means  of  the  bichromate  solution. 
10  c.c.  more  were  filtered and  also  precipitated  in  the  same  manner. 
This  procedure  was  employed  with  the  object  of  determining  the 
difference  between  the  acetate  as  found  and  the  actual  amount  of 
soluble  acetate  in  the  sample. 
EXAMINATION  OF  COMMERCIAL  LEAD  ACETATE. 
Appear- 
ance. 
Appearan'e 
of  Sol.  in 
H20 
Precipita'n 
with  Pot. 
Ferro- 
cyanide. 
n 
10 
K2Cr20"7 
Titrate  of 
Acidulated 
Unfiltered 
Sol. 
Titration 
of  Filtered 
Sol. 
Treatment 
with 
NH4OH 
after  Pptg. 
with 
H2S04. 
Fe. 
Ca. 
Granular 
marked 
Very 
Flocculent 
I 
C  P. 
opalescent 
Pure  white 
268 
26-5 
reddish 
Present 
Present 
2 
do 
do 
do 
286 
27"3 
do 
do 
do 
3 
Granular 
do 
do 
26-9 
26  5 
do 
do 
do 
Slightly 
do 
do 
4 
Crystals 
opalescent 
27-9 
27*2 
do 
do 
5 
do 
do 
do 
27-8 
27-3 
do 
do 
do 
Somewhat 
6 
do 
opalescent 
do 
26*9 
267 
do 
do 
do 
do 
Slightly 
do 
do 
7 
opalescent 
27"o 
265 
do 
do 
Mixture  of 
powd.  and 
8 
crystals 
Opalescent 
do 
26  3 
26*0 
do 
do 
do 
Mixture  of 
opalescent 
9 
andcryst'ls 
do 
do 
26-8 
26*5 
do 
do 
do 
Opalescent 
do 
do 
do 
do 
10 
pieces 
do 
28-0 
27-2 
11 
do 
do 
do 
267 
26'4 
do 
do 
do 
Marked 
C  P. 
U.  S.  P. 
12 
muchefflor. 
do 
do 
297 
29*2 
do 
do 
do 
13 
Crystals 
do 
do 
28-1 
277 
do 
do 
do 
Mixture  of 
powd.  and 
crystals 
do 
do 
27-9 
27-1 
do 
do 
do 
Slightly 
do 
do 
do 
15 
Crystals 
opalescent 
do 
27*1 
267 
