268 C H E M I 
tion cf this acid, gives it the fame colour. Ether and 
alcohol, boiled a fhort time in this fubftance, produce 
the fame effedf. The muriatic acid, heated in a retort 
with this acid, either folid or in folution, produces a briik 
effervefcence 5 a quantity of oxygenated muriatic acid is 
produced, and the liquor a flumes a fine dark-green co¬ 
lour. This acid, mixed with a folution of hydro-fnl- 
phure of potalh, is precipitated in the form of green ifli- 
brown flakes. Heated with the blow-pipe, it boils up, 
and leaves a green infulible matter. Melted with phof- 
phoric glafs and borax, it produces vitreous pearls of a 
beautiful emerald-green. 
Earthy and Alkaline Chromats. 
Chromat of Barytes. —The chromic acid eafdy 
unites with barytes; it forms with this earth a fait very 
little l’oluble in water; for, by pouring liquid chromic 
acid into a folution of this earth, a precipitate of a pale 
citron colour, is produced ; but the fait is not entirely in- 
foluble, for the liquor ftill preferves a flightly-yellow co¬ 
lour, though the two principles of the fait be reciprocally 
faturated. This pulverulent fait has no fenfible tafte: 
it is decompofed by mineral acids ; gives out vital air, or 
oxygen gas, by means of heat; and there remains an 
earthy mafs of a green colour. 
Chromat of Lime.— This fait, formed by the com¬ 
bination of lime with the chromic acid, differs from the 
barytic chromat only in having alefs degree of folubility, 
and by different affinities and proportions in its principles. 
With fire, and with acids, its effefts are the fame. 
Alkaline Chromats, —The moll Ample procefs for 
preparing thefe falts, is to boil one part of red-lead in 
fine powder, with two parts of alkali, (whether potalh, 
foda, or ammoniac,) and forty parts of water. Hereby 
a double affinity is put in adiion; by which carbonat of 
lead is formed, which falls to the bottom, and a combi¬ 
nation of the acid of the lead with the alkali employed, 
which combination, being foluble, remains in the water. 
The colour of thefe combinations of the acid with the 
alkalis, is a pale yellow ; that with ammoniac is in yellow 
laminae, Ihining like gold. Their folutions produce cryf- 
tals of nearly the fame colour, but rather darker; their 
ihape has not been alcertained. . 
_ Thefe falts are decompofed by barytes, lime, and ftron- 
tian. The mineral acids decompofe them alfo. They 
give out oxygen gas by the adlion of'fire, and the refidue 
is a green mafs; but that with ammoniac muff be again 
excepted, for its bafe is partly decompofed by the oxygen 
of the acid, and it leaves in the retort a pure green oxyd, 
becaufe that portion of the ammoniac which is not de¬ 
compofed flies off in vapours. By double affinity, thefe 
kilts decompofe the calcareous, barytic, magneiian, and 
aluminous, lalts. 
To reduce this acid to the metallic ftate, take feventy- 
two parts of the chromic acid ; put it into a crucible of 
charcoal, enclofed in another crucible of porcelain, filled 
with charcoal-duft; place the apparatus in a forge-fur¬ 
nace, and heat it for an hour with a very brifk fire. In 
the hollow of the charcoal will be found a metallic mafs 
of a light-grey colour, formed of needles interwoven to¬ 
gether. From feventy-two parts, Vauquelin obtained 
forty-four parts of metal. 
This metal is very brittle, infulible, fixed, and cryf- 
tallized in needles. Expofed to heat with a blow-pipe, 
a lilac-coloured cruft is formed over it, which grows green 
in cooling. Heated in the fame manner with borax, it 
does not melt; but part of.it, after being oxydated, dif- 
lolves in the lalt, communicating to it a very beautiful 
green colour. Acids have but very little effedf upon it, 
the nitric acid only producing any remarkable change ; 
by diftilling five or fix times fuccefiively, to drynefs, twen¬ 
ty parts of concentrated nitric acid with one of the me¬ 
tal,- it is converted into an orange-coloured powder, 
which at firll is green. This powder has all the proper¬ 
ties of the chromic acid. The ufes of this metal are not 
S T R Y. 
yet known. Perhaps it may afford beautiful and durable 
colours to the painter and enameller. 
Of TITANIUM. 
The fubftance whence titanium is extradled, is the red 
fchorl, principally found in Hungary ; but it has fince 
been found in France, in the province of Brittany, can¬ 
ton of St. Yrieux. It alfo appears to be the fame fubftance 
with that which Mr. M‘Gregor found in an iron ore, 
from Menakan in Cornwall, and of which he eftablifhes 
an interefting account, in Crell’s Journal for,1791. The 
red fchorl found in Franee is in fome fpecimens of a bright 
red colour, in others darker. It is found at the furface 
of the foil, in lumps never more than an inch in diameter, 
and generally appear rubbed or worn on the furface; 
fome preferve a regular cryftalline form. It is very hard, 
will cut glafs, and is difficultly reduced to powder. The 
pieces which fly off under the hammer are very bright, 
with polilhedfurfaces. This oxyd, melted with fmalt, gives 
to porcelain a pure regular Itraw-colour. It has been 
long ufed at the manufadture of Sevres, to give porcelain 
a brown colour. 
If red fchorl be mixed with carbonat of potafh, the 
fchorl feparates from the potalh a certain quantity of 
carbonic acid. For this purpole, 100 parts of red fchorl, 
found in France, were reduced to powder and melted in 
a crucible with 600 of carbonat of potafh ; the mixture 
acquired a greenifh colour. By dilution with boiling 
water, this melted mafs afforded a whitilh precipitate, 
which, after being waflied and dried, weighed 157 parts. 
The alkaline liquor contained only a fmall portion of 
filex and alumine, which it feemed to have taken from 
the crucible ; it held cauftic potalh in folution, and the 
precipitate itfelf poffefled the property of eft’ervefeing 
with acids. This precipitate loft 0-25 of its weight by 
expofing it Amply to a ftrongheat. Vauquelin and Hecht, 
therefore, confider this precipitate as a combination of 
the metallic oxyd with carbonic acid, and call it the car¬ 
bonat of titanium. 
To reduce this oxyd in the dry w r ay, take carbonat of 
titanium, prepared as above ; make it into a palte with 
fifli-oil; place it in a hollow formed of finely-powdered 
charcoal with a little alumine ; expofe it for an hour and 
a half to a very ftrong heat: a blackilh irregular mafs 
will be produced, fome of whofe points have a reddifh 
metallic colour. This is the titanium in the metallic Hate. 
Acids have a fenfible adtion upon this metal. If a 
fmall quantity of the metallic titanium be boiled with 
pure nitric acid, there is not much adlion between thefe 
two bodies ; yet the metallic brightnefs dilappears from 
the furface, and is occupied by a whitilh fubftance. With 
the nitro-muriatic acid, a white powder is formed, which 
fpreads all over the liquor; the furface of the titanium 
is covered with a white pellicle. With fulphuric acid, 
as foon as ebullition begins, fulphureous acid vapours 
are difengaged, and the matter changes into a wffiite pow¬ 
der, of which a part remains in folution in the fulphu¬ 
ric acid. 
Although the matter of red fchorl has not yet been 
completely melted and reduced, yet thole who carefully 
examine the experiments of Klaproth, Vauquelin, and 
Hecht, muft conclude, that red fchorl is a diftindt me¬ 
tallic fubftance, exilling in nature in the oxyd ftate, and 
whofe general properties place it among brittle and oxy- 
dable metals. 
Of URANIUM. 
This metal was lately difeovered by Klaproth; it has 
not yet been found native. Klaproth called urunite , or 
uranium, from uranus, the name which Bode gave to 
Herfchel’s newly-difcovered planet, by us called the 
Georgium fidus. Klaproth detedfed this metal, combined 
in a certain mineral, found in a mine belonging to George 
Wagsforfl, at John-Georgenftadt, in Germany. Its-dif- 
coverer, Klaproth, to whom we ow'e its analyfis alio, firfli 
-s extradited 
