on the Nature of certain Bodies. 463 
a dark gray colour,* and was harsh to the touch ; it had no 
taste, and at common temperatures no smell ; but when 
heated, it emitted the peculiar odour of sulphur. Its specific 
gravity was rather less than that of sulphur. It softened at a 
low heat, so as to be moulded like wax between the fingers. 
It was a non-conductor of electricity. When heated upon a 
surface of glass, it soon fused, entered into ebullition, took 
fire, and burnt with the same light blue flame as sulphur. A 
small particle of it, made to combine with silver, presented the 
same phenomena as sulphur. 
The substance from the phosphuret was of an amber colour, 
and opaque. It could not be examined in the air, in the form 
in which it was collected (that of a loose powder) for as 
soon as it was wiped dry, it took fire, and burnt in the same 
manner as phosphorus ; when melted under naphtha, it was 
found to differ from phosphorus, in being much deeper co- 
loured, perfectly opaque, and very brittle. Its fusibility was 
nearly the same, and, like common phosphorus, it was per- 
fectly non-conducting. 
In experiments upon the union of potassium with sulphur 
and phosphorus the heat is so intense, that when larger quan- 
tities than a few grains are used, the glass tubes are uniformly 
fused or broken in pieces, and in consequence I have not been 
able to operate upon such a scale, as to make an accurate exa- 
mination of the substances just described, and to determine 
the quantity of oxygene they absorb in being converted into 
acid. Metallic vessels of course cannot be employed ; but I 
* Possibly this colour may have been produced by the decomposition of a film of 
soap of naphtha adhering to the potassium. 
3 ° 2 
