3© Mr. Davy's Experiments on 
which Mr. Hatchett had the kindness to give me for the pur- 
poses of these experiments, and which must have been precipi- 
tated by potash, or from a solution in potash, I found that a 
sufficient quantity of alkali adhered to it, even after it had been 
well washed, to produce an alloy of potassium and tellurium ; 
but in this alloy the potassium was in very small quantity. It 
was of a steel gray colour, very brittle, and much more fusible 
than tellurium. 
I shall not arrest the progress of discussion, by entering at 
present into a minute detail of the properties of the aeriform 
compound of tellurium and hydrogene ; I shall mention 
merely some of its most remarkable qualities, and agencies, 
which, as will be shewn towards the close of this paper, tend 
to elucidate many points immediately connected with the sub- 
ject in question. The compound of tellurium and hydrogene, 
is more analogous to sulphuretted hydrogene, than to any 
other body. The smell of the two substances is almost 
precisely the same.* Its aqueous solution is of a claret colour ; 
* In some experiments, made on the action of tellurium and potassium, in the la- 
boratory of my friend John George Children, Esq. ofTunbridge, in which Mr. 
Children, Mr. Pepys, and Mr. Warburton co-operated, the analogy between 
the two substances struck us so forcibly, as for some time to induce us to conceive 
that tellurium might contain sulphur, not manifested in any other way but by the 
action of Voltaic electricity, or by potassium ; and some researches made upon the 
habitudes of different metallic sulphurets, at the Voltaic negative surface, rather 
confirmed thesuspicion,formostofthe sulphurets that we tried, which were conductors 
of electricity, absorbed hydrogene in the voltaic circuit. The great improbability, how- 
ever, of the circumstance that sulphuric acid, or sulphur in any state of oxygenation 
could exist in a metallic solution, which was not manifested by the action of barytes, 
induced me to resist the inference ; and further researches, made in the laboratory «f 
the Royal Institution, proved that the substance in question was a new and singular 
combination. 
