Lead , 
183 
which amounted to 8*5 grains. The lead was then pre- 
cipitated by caustic potash and the oxyd thus procured 
weighed, after thorough drying, 85 1-2 grains, which is 
the state of oxygenation in which it is supposed to exist in 
the ore. In this case, therefore, 85.5 grains of oxyd of 
lead were combined with only 8.5 of muriatic acid which 
is far short of the saturating quantity, since in the artificial 
crystallized muriat of lead the proportion of acid amounts 
to 13 or 14 per cent. This deficient saturation therefore 
allows the presence of carbonic acid, which amounts to 
6 grains, and completes the saturation of oxyd. 
A similar ore was analyzed by Mr. Chenevix, nearly in 
the same way and with the same result. The ore was 
first dissolved in nitric acid, and the quantity of carbonic 
acid, amounting to 6 grains, estimated by the loss after 
effervescence. The solution was then neutralized by am- 
monia, and tried by different tests. As nitrate of lime 
gave no precipitate, the solution could not contain either 
the arsenic or molybdic or phosphoric acids, and as nitrat 
of barytes gave none, the absence of sulphuric acid was 
proved. 
Nitrat of silver was then added and a copious precipi- 
tate ensued, and the luna cornea weighed after drying 48 
grains, which Mr. C. estimates as equivalent to 8 of mm 
riatic acid. The composition of the ore is thus stated : 
6 grains of carbonic acid saturate 34 of oxyd of lead, and 
8 of muriatic acid saturate 51 of oxyd of lead, and the 
acids may be supposed to be in the state of perfect satu- 
ration, consequently the ore is composed of 59 muriat of 
lead and 40 of carbonat of lead ; or of 14 of acid and 85 
of oxyd. 
The Anglesea sulphat of lead was thus analyzed by 
Klaproth : 100 grains were first ignited moderately and 
lost two grains, which were water of crystallization. The 
remainder was mixed with 400 grains of carbonated pot- 
