244° Dr. Zeise on a new Class [Ocr. 
distinctly observed in this combustion : during the first, it melts 
into a reddish-brown substance, which, when again inflamed, 
burns and throws the sparks still more violently around. The 
red mass itself is likewise combustible, and exhibits immediately 
violent combustion with white sparks. If the salt be thrown 
on red-hot glass, or charcoal, it is quickly consuméd. I appre- 
hend the cause of this phenomenon to be, that a compound of 
potassium and sulphur is suddenly formed, while carbon and a 
gas are separated, and that these small particles of carbon when 
thrown about produce the white burning sparks. I find this 
theory supported by the phenomena which take place when the 
salt is decomposed by heat in close vessels. 
The hydrocarbosulphate of soda crystallizes more difficultly, 
and in a form quite different from that of the salt of potash; it 
deliquesces in moist air, and is not separated from its solution in 
alcohol by means of sulphuric ether; with acids and salts of 
metals, it exhibits the same phenomena as the hydrocarbosul- 
phate of potash. 
Hydrocarbosulphate of lime is obtained by mixing a solution 
of muriate of lime in alcohol, with a solution of the hydrocarbo- 
sulphate of potash ; muriate of potash is precipitated, and the 
hydrocarbosulphate of lime remains pretty pure, dissolved in the 
alcohol ; for though the muriate of potash is soluble in alcohol, 
the salt of lime almost entirely prevents its solution. 
I consider the compounds that are separated when the hydro- 
carbosulphate of potash is mixed with solutions of certain metals 
to consist of the metal and a kind of sulphuret of carbon without 
oxygen. Zinc, however, may make an exception. The carbo- 
sulphuret of copper has a fine lively yellow colour, the carbosul- 
phuret oflead and the carbosulphuret of mercury are white; the 
first, however, has a foliated, shining, crystalline appearance ; 
the second is granular. The carbosulphuret of copper is pre- 
pared by pouring an aqueous solution of the hydrocarbosulphate 
of potash into a solution of sulphate or nitrate of copper. The 
precipitate, when washed with water, is pure. The carbosulphuret 
of lead is prepared in the same way from nitrate of lead, and the 
carbosulphuret of mercury from corrosive sublimate, or prussiate 
of mercury. They are all insoluble in water, but the carbosul- 
phuret of lead and of mercury at least are soluble in alcohol. 
The carbosulphuret of mercury is soluble in a concentrated solu- 
tion of the hydrocarbosulphate of potash, and it seems to form 
with it a saline compound. Strong acids act very slowly on 
these compounds, and by themselves they may be exposed to 
the heat of boiling water without being decomposed. When 
heated ina glass tube, the carbosulphuret of copper and that of 
lead produce at a certain temperature a mist in the vessel, which 
is condensed into a yellow liquid, with a smell like onions, and 
the exact appearance of oil; afterwards it melts, gives out gas 
with violent effervescence, and in considerable quantity; then 
