Lead in Lead Amalgam 195 
by adding a known weight of lead to 40 to 50 grams of mercury and 
allowing it to dissolve in the mercury before the addition of the solu- 
tion of copper nitrate. The results shown in Table V indicate that 
the method is satisfactory for a quantitative determination of the lead 
in a lead amalgam. 
SUMMARY. 
The material presented in this paper includes: 
1. A brief review of some of the methods that have been proposed 
for determining the concentration of lead in lead amalgams, together 
with a consideration of the possibility of applying them to the analysis 
of such amalgams containing a large amount of mercury and a rela- 
tively small amount of lead. 
2. An account of some experiments made with the object of de- 
veloping a more desirable procedure for the above determination. This 
work has involved the following determinations: 
a. The loss in weight of lead amalgams during washing. 
b. The amount of lead in lead amalgams by weighing the metal 
as the sulfate and as the chromate. 
ce. The solubility of lead sulfate and of lead chromate in an aque- 
ous solution of copper nitrate. 
Department of Chemistry, Purdue University. 
