168 Proceedings of Indiana Academy of Science. 
product, which consisted of fine crystals, fused to a clear liquid on heat- 
ing and sublimed without leaving any residue. On examination by 
means of the spectroscope it was found to give the thallium line and 
very faint sodium lines. This salt was introduced in a hard glass tube, 
one end of which was drawn to a capillary and inserted in a small hole 
bored in the stem of a Bunsen burner. The other end of the tube was 
connected with the air blast. A very slow current of air was turned 
on, the burner was lighted, and the thallous chloride in the hard glass 
tube was heated to volatilization. The vapors of this salt on entering 
the flame imparted to it the characteristic thallium green color. On 
depressing the flame with a cold object, such as an evaporating dish, 
a metallic mirror of a brownish appearance was obtained. That this 
mirror was due to the deposition of thallium was proved by moistening 
it with a drop of hydrochloric acid and impinging a Bunsen flame on it; 
the characteristic green color flashed up. 
Thallous Chloride in the Hydrogen-Air Flame.—Resublimed thallous 
chloride was placed in a hard glass tube provided with a platinum tip. 
Hydrogen, generated from zine and _ sulphuric 
acid and washed through a solution of silver 
nitrate, was passed through the tube and 
e ignited above the platinum tip. The thailous 
chloride was now heated with a flattened 
Bunsen flame. The flame of the burning hydro- 
gen, on becoming charged with the vapors of the 
thallium salt, was seen to consist of a long, slen- 
der inner cone, deep green in color, surrounded 
d by a film which was almost colorless. The middle 
cone, which constituted the main part of the 
flame, was green for about two-thirds of its 
length, its lower third being blue. The outer 
cone, which formed the tip of the flame, was of 
CG an intense green color. The terms inner, middle 
and outer cones are used for the purpose of sim- 
plifying the description of the flame. Reference 
to the accompanying diagram will show that in 
practice the flame consists of five different zones, 
each zone having its own characteristic lumi- 
nescence. On depressing the inner zone (a) with 
Diagram of the Hydrogen. a Cold object a lustrous dark metallic mirror of 
po Hata abereet with a brownish tinge was obtained. But no deposit 
a, deep green; b, almost col. Of thallium was obtained when the part of the 
orless film; ec, blue; d, green; 2 E . es E a 
e, deep green. flame above the inner zone was depressed. 
a 
