TRANSACTIONS OF THE SECTIONS. 35 
Karthy matter. cicesssesseecesecssees | OVB 
PbO 
LPM TEG WI « Gal Gals delfeben’s> io) Basse 
Alumina,....... MEMR bea Pile es ew 280 
HeO@ inten aevisate Sine ele daltate a aaaeeleniie lee AOD 
MaiOw sciz Biles i Dewan s Siete GS 
CaO’... stete ben ptitanta lotsa oe deren 
: MiOhresi, 0 ernie renner 0:55 
BOP eM oes eRe ee Jig contd 
Ors riaens Ai GCG Doi id Gade 7:55 
PAHIELS APN. RNASE ee aia davateiers 3 “1680 
Se As Zn, &c. not estimated. .........05 eneBd: 
100-00 
Wishing to free the solution, obtained by treating this mass with water, from iron, 
lime was added. This plan was not the one ultimately adopted, but during its ap- 
plication a considerable quantity of ammoniacal vapours pe their appearance, and 
hese were afterwards found to be due to the presence of sulphate of ammonia in the 
sublimate itself, possibly due to the fact that some pyrites from the collieries is used, 
and adhering coaly matter may have given rise to the generation of the alkali. 
A concentrated hot solution of all the salts obtained from 4 cwt. of the flue sub- 
limate gave a salt which fell in granular crystals; others of an octahedral shape 
fell subsequently from the same solution, and were found on analysis to consist of 
Oe PBDEs F800 a Set Beet cte i . 86°50 
US IA eae Sco ct 9 cic 26-40 
AO PETE Hi! ot ERE IER Mindat 9:50 
BeGecest ocean Ae eee ie-B0 
PAOD (2 P32. eaey, valtat eee QOed 
Ag H\(not weighed). ...5.% saete veleleielee ly . 5:35 
100-00 
As a source of thallium, the whole solution was treated in two ways. 
~ First, the solution not sufficiently strong to give any crystals was filtered, and to 
it a piece of sheet zinc was added; this, by its conversion into sulphate of zine, 
gave the thallium as a metallic precipitate, but contaminated with the impurity of 
the zinc. This metallic precipitate was washed with water and again dissolved in 
sulphuric acid, and then precipitated by means of hydrochloric acid. The chloride 
of thallium being feebly soluble in water, the washings of the chloride were pre- 
served and used for washing out, in subsequent operations, the sulphate of thallium 
from flue-dust. The pure chloride thus obtained was either reconverted into sul- 
hate and then precipitated by an electric current, or the chloride was fused, placed 
in a dish, after cooling in water, with a piece of zinc, which reduced the metallic 
thallium as before. The metal itself preserves the exact physical structure of the 
cake of the chloride of thallium. The metal so obtained by either of these modes 
was melted, and both were of the same degree of purity. They gave the following 
results on analysis :— 
TUES SLLTTITVN SG eiietane och ssapekens slahutnst oaideae pe ses. 98:66 
Siva: aa cbc}: Bas, herds id dew ost un, okstace ke ioe 36 
5 es Ate ok bie ids) il boeiias ae Prin 84 
TIRE US San wisiby 5 us ceteas aid. sudnniey tea uses EaaRnOUe ih 64 
100-00 
The" second and more economical mode of treatment consisted in taking the 
solution obtained from the flue sublimate and adding chloride of sodium until all 
precipitation ceased. The acid solution remaining after the chloride has been pre- 
cipitated, contains more thallium than an ordinary neutral solution, and in conse- 
quence was preserved. The solution was concentrated, and crystals of sulphate of 
iron and sulphate of ammonia separated. The mother-liquor, on being treated with 
chromate of potass, gave chromate of thallium, which was exhibited a of the 
