Mr. W. H. Balmain on Zthogen and Aithonides. 469 
surface of the substance in powder, as when a glass tube soiled 
with it is held at the extreme point of the flame, it presents a 
beautiful green phosphorescence, owing no doubt to the for- 
mation of boracic acid at the surface, and if it be removed to 
the inner flame, the centre will incandesce, while the outer 
edges, where it meets with the oxygen of the air, will still 
yield the beautiful elegant green. When thrown upon fused 
chlorate of potass it deflagrates with a soft green light, and it 
will also deflagrate with nitrate of potass, It is not altered 
by being gently heated with potassium or sodium, nor when 
heated before the blowpipe on charcoal with lead, zinc, &c. 
Chlorine has no action upon it at a low red heat, and iodine, 
sulphur and corrosive sublimate may be sublimed from it 
without decomposing it. It is not decomposed by hydrogen 
at a red heat, but below that temperature is decomposed with 
the evolution of ammonia by the vapour of water, or by any 
substance which will yield water, as hydrate of potass, hydrate 
of lime, common clay, hydrated phosphoric acid and the rhom- 
bic phosphate of soda. It is not decomposed by hydrochloric 
acid at a low red heat, and I thinkit is not altered by hydro- 
fluoric acid, for a small portion of it was mixed with a large 
quantity of fluorspar, with more than sufficient sulphuric acid 
to make it all into hydrofluoric acid, and heated as long as 
fumes passed off, when, after the sulphate of lime had been 
washed away with dilute nitric acid, it still yielded ammonia 
with hydrate of lime. 
LEthonide of Zinc. Preparation—Heat together, to white- 
ness, in a lined crucible, one part of anhydrous boracic acid 
and two and a half parts of cyanide of zinc—or heat finely 
granulated zinc with zthogen to the temperature at which 
zinc sublimes, and wash the result with nitric acid. 
Properties.—A white solid resembling the last, gives am- 
monia abundantly when heated with a mixture of hydrate of 
lime and carbonate of potass, and is insoluble (with or without 
heat) in water, sulphuric acid, hydrochloric acid, nitric acid, 
solution of potass and ammonia. It is not decomposed by 
chlorine or hydrogen at a full red heat, nor by corrosive sub- 
limate, nor by potassium or sodium. Before the blowpipe it 
is infusible, but in the oxidizing flame communicates a green 
colour, and when at the outer edge emits a very brilliant 
bluish phosphorescence, which appearance it also produces 
when simply dropped into the flame of aspirit-lamp. Thrown 
on fused chlorate of potass, it deflagrates with a faint blue 
light. 
LEthonide of lead may be obtained by heating chloride 
of lead with aethonide of zinc, or by heating boracic acid with 
