36 REPORT—1863. 
salts of this metal. The chloride of thallium so obtained was treated in the man- 
ner already described for procuring the metal. Before pec the subject of the 
flue dust, it may be well to say that it consisted principally of sulphate of lead, 
caused by the presence of sulphide of lead in the pyrites, earthy matter, &c., with 
a small ee of thallium, as was manifest in reducing the sulphate of lead, when 
the metalliclead was found to contain thallium, as shown by the subjoined analysis. 
BEY el TUT signs, agd ceatastrerocenais, aris ie ayeters| a) ayn lohoe 7:69 
RD Sai erence Boke inchoate 91°53 
MOSS as Bavayelaraey cyenaiels phy ste) alareneisiere cheveyedelee ‘78 
100-00 
In all, about eight pounds of thallium have been procured in the way described. 
Six pounds of metallic thallium were exhibited; one pound was presented to Mr. 
Crookes and to some chemical friends in Paris, and the remainder has been employed 
in forming the salts exhibited, viz. :— 
Sulphate.—Sulphuric acid dissolves the metal with great readiness, giving off 
hydrogen, the solution on concentration affording crystals. 
Mitrate.—Nitric acid also dissolves the metal with ease, giving off nitrous 
vapours, the solution affording crystals in the ordinary way. 
Carbonate.—A solution of thallium not being, like that of lead, &c., precipitated 
by an alkaline carbonate, the following process was followed. The spongy metallic 
thallium precipitated by zinc from the chloride was moistened and heated gently 
and exposed to the air.” The greater portion of the thallium oxidized, which oxide 
was then dissolved in water, and a stream of carbonic acid was passed through the 
solution. This converted the oxide into carbonate, and from the solution of carbo- 
nate of thallium so obtained, crystals of this salt were procured by concentration in 
the usual way. Exposure to the atmosphere produced similar results, 7. e. carbonic 
acid was absorbed, just.in the same way as happens when solutions of potass, soda, 
lime, &c. are similarly treated. 
Chromate, obtained in the way already described, by adding chromate of potass 
to a solution of any soluble salt of thallium, 
Bichromate, got’ by using bichromate instead of the chromate. If the bichro- 
mate is precipitated from an acid solution and heated to ebullition, and the solution 
allowed to cool, the crystals fall in brilliant scales, as may be seen on examining 
the specimens. 
Chloride of Thallium, obtained in the way already mentioned, as a precipitate. 
This precipitate, dissolved in a boiling solution of muriate of ammonia, gave crystals 
on cooling, the chloride being more soluble in muriate of ammonia than in water. 
A specimen of melted chloride answering to what may be denominated horn thal- 
lium was also prepared. 
Sesquichloride of Thallium.—On treating the chloride of thallium with boiling 
nitric acid, all the chloride dissolves, and the solution, on cooling, deposits brilliant 
ellow scales of a sesquichloride. This sesquichloride was exhibited, after having 
een melted. 
Iodide of Thallium, obtained by precipitating a solution of sulphate of thallium 
by iodide of potassium, giving a very insoluble yellow precipitate, which, on being 
heated when dry, changes to orange, regaining the primitive colour on cooling. 
Sulphate of Thallium and of Alumina.—The addition of the sulphate of alumina 
to a solution of sulphate of thallium gave this double salt resembling in form those 
of alum; and, indeed, this substance may be considered as a thallium-alum. The 
existence of a double salt of this description is interesting, inasmuch as it forms a 
link with the alkalies. 
Sulphate of Thallium and of Soda.—On adding caustic soda to the solution of 
sulphate of thallium, in treating the flue sublimate with hot water, iron is first 
thrown down and ammonia given off. The hot strong solution on cooling gives 
erystals of sulphate of soda, containing sulphate of thallium; but whether mecha- 
nically or otherwise, want of time has not permitted the determination. A speci- 
men of these crystals was shown. 
Sulphocyanide of Thallium.—When a solution of sulphate of thallium has added 
