ee 
Chemistry and Physics. 137 
crystals separated, having five molecules crystal water. The 
attempt to produce a thallium compound like the silver one w a 
not successful, With lead by adding to a hot saturated solut 
of sugar of lead in boiling alcohol, a strong alcoholic clation ‘of 
potassium triiodide, the liquid deposited on cooling sm 
ormed crystals, hiv prisms aggregated in clumps, poo 
dichroic and permanent in the air. On analysis it gave the 
remarkable empirical formula Pb,C,,H,,0,,K,I,,. No rational 
formula for it has yet been obtained.—Jour. Ch. Soc., Xxxili, 183, 
May, 1878. G. F. B. 
on Two new Cyanogen Products, —— and —— 
PSON igs gai that when coal pire containing a lar 
mercuric A ay is potassium hy Banta, Actas precipitate is 
formed, which finally becomes of a beautiful scarlet. To prepare 
it directly mercuric oxide is boiled with potassium cyanide, adding 
potassium hydrate in excess , agitating with CS, and gently warm- 
ing. When washed and dried it resembles vermilion in color, but 
ra tint is not as violet. It sublimes toa Jet black mass on heat- 
iovvints HgsS CH, and is attacked only by aqua regia and chlorine 
3 
replaced by copper, ap leah an equally explosive ede. ex 
plosions in brass or copper gas pipes may be due to ies copper 
compound si bones by the CS, in the gas.—Ber 
Ges., aa 73 Jour. Chem. Soc., xxxiii, 404 ee 
ium two lifforent fsa LR, by ignition of iaaasia: 
gallium alum, and by calcination of the nitrate, pnsbinnte from a 
known weight of the al. The ammoni ] was 
prepared with the metal recently obtained by the author in con- 
ee with Jungfleish. nice repeated cry se ae vam = 
traces of zine and of copper were eliminated. The 
h came — 
