the Carinthian Molybdate of Lead. 289 
after it bad been washed and dried, was subjected to tbe same 
experiments as tbe abovementioned crystals, and exhibited the 
same properties, excepting that it did not dissolve in distilled 
water till some drops of muriatic acid were added. 
When the solution was evaporated in a glass bason, the rest 
of the oxyde of molybdasna was deposited in the form of a 
heavy citron-coloured powder. 
The white oxyde of lead on the filter through which the so- 
lution of the alkaline mass had passed, was found to be mixed 
with siliceous earth. When melted on charcoal, it did not 
entirely assume the metallic form, but a part changed into a 
small grain of transparent yellowish vitrified oxyde of lead. 
Mr. Klaproth observes, that in this experiment the presence 
of the siliceous earth prevented the complete reduction of the 
lead, in the same manner as when glass of lead, composed of 
three parts of oxyde of lead and one of siliceous earth, is melted 
upon charcoal. He therefore dissolved this oxyde in weak ni- 
tric acid, separated the siliceous earth by a filter, and precipi- 
tated the lead by sulphuric acid. 
Mr. Klaproth, however, doubts whether the greater part 
of the siliceous earth was not introduced, during the operation, 
by the action of the alkali on the crucible. 
A drachm of the ore was digested with a considerable quan- 
tity of nitric acid, and a great part was dissolved. In the so- 
lution white flocculi were perceived, and were separated by a 
filter. When dried they were like a membrane, which became 
bluish when exposed to the light, and much resembled the 
molybdic acid obtained from molybdacna, by repeatedly dis- 
tilling nitric acid from it. In the filtrated nitric solution 
there was much oxyde of molybdaena mixed with oxyde of 
P p 2 
