Lead . 
IBS 
tite of lead added. The phosphoric acid in the solution,, 
was then precipitated in the form of phosphat of lead, 
weighing, after ignition, 82 grains, of which the mere acid 
amounts to 18.37 grains. The rest of the solution was 
then mixed with a little muriatic acid, inspissiated by 
evaporation, and alcohol added to redissolve the muriat 
of iron then formed, if any, from which by the addition 
of prussiat of potash there was obtained an extremely 
small blue precipitate, indicating no more than about .1 
of a grain of oxyd of iron. 
In another experiment the phosphoric acid, instead of 
being engaged with lead, was saturated partly by soda, 
partly by ammonia, and by due evaporation and cooling, 
crystals of the microcosmic salt, or the phosphat of soda 
and ammonia were obtained. The other varieties of this 
phosphat were analyzed in the same way. 
With regard to the analysis of the molybdat of lead the 
reader is referred to the article Molybdena and to Chrome , 
for the Chromat of lead. Those ores in which lead is 
only a small part of the metallic contents will be described 
under the other metals as silver, bismuth, &c. 
The compound of oxyd of arsenic, lead, and iron, ex- 
amined by Lelievre, and Vauquelin, gave the following ap- 
pearances : 100 parts roasted for half an hour, with a lit- 
tle suet added occasionally to favour the evaporation of 
the arsenic, lost 38, and became black and magneticah 
The remaining 62 parts boiled in muriatic acid made a 
red solution, giving out much oxymuriatic acid gas, 
and crystallized muriat of lead was deposited. This so- 
lution evaporated, redissolved in water, and decomposed 
by sulphat of soda, gave 25 of sulphat of lead, equal to 
20.2 of lead or 22 of the oxyd. The residue, saturated 
with ammonia, gave 39 parts of oxyd of iron. 
The analysis of lead ores in the dry way is attended 
A a 
VOL. III. 
