114 NATURAL HISTORY. [jLQNG 
Zinnwald in Bohemia, formerly confounded with the 
molybdate of this metal. 
Molybdic acid and molybdates ;— ochry molybdenum or 
molybdic acid, as a yellow powder on the sulphuret of this 
metal, from Sweden, &c.;— molybdate of lead, or yellow 
lead ore, massive, lamelliform, and crystallized in splendid 
groups on compact limestone, &c.; chiefly from Bleiberg 
in Carinthia. 
Case 41. Oxide of chromium and chromates :—a suite 
of specimens of chromate of lead, or red lead ore, from the 
gold mines of Beresof in Siberia, where it chiefly occurs in 
a kind of micaceous rock, mixed with particles of quartz 
and brown iron-stone ;— chromate of lead and copper, called 
vauquelinite, a concomitant of the Siberian red lead ore;— 
chromate of iron, from the department of Var in France, 
and from Baltimore in Maryland, intermixed with talc 
stained purple by chromic acid. 
Vanadic acid and vanadiates. Vanadium was disco¬ 
vered in some ores of iron from Taberg in Smaland, by 
Sefstrom : by Del Rio the acid of this metal, which he 
called erythronium, had been found, combined with oxide 
of lead, in the brown lead ore of Zimapan in Mexico. 
For the discovery of the vanadiate of lead at Wanloek- 
hed, and the analysis of this mineral substance, science is 
indebted to Mr. Johnston, of Edinburgh.—Vanadiate of 
lead from Beresof, Siberia. 
Boracic acid ( sassoline ) and borates ;— borate of soda, 
the salt known by the names of borax and tincal, from 
Tibet, Monte-rotondo, Tuscany, &c.— borate of magnesia 
or boracite in separate crystals, and the same embedded 
in gypsum ;— datolite, being a borate with tri-silicate of 
lime, from Arendahl in Norway ; the variety from Sont- 
hofen (supposed to be a distinct species, called humbold- 
tite by Levy) ; and the globular-fibrous variety (which has 
received the name of botryolite) likewise from Arendahl. 
In this Case begins the family of the Carbonates.— Car¬ 
bonate of soda, from various localities, and among which is 
the African trona.— Carbonate of strontia, also called 
strontianite, in prismatic and acicular crystals, which latter 
have sometimes been mistaken for arragonite.— Carbonate 
of baryta or wither it e, among the specimens of which may 
