Sulphur and Phosphorus . ^53 
retted hydrogene evolved by the action of the acid, is from 
y 7 _ to J- ; but if heat be applied to the combination, so as to 
drive off the superfluous sulphur, the quantity of gas collected 
is very little inferior to that produced from the combination 
in which a small proportion of sulphur is used ; and I am in- 
clined to believe, from the phenomena presented in a great 
number of experiments, that sulphur and potassium, when 
heated together under common circumstances, combine only 
in one proportion, in which the metal is to the sulphur nearly 
as 3 to 1 in weight ; and in which the quantities are such 
that the compound burns into neutral sulphate of potash. 
When a grain of potassium is made to act upon about 1.1 
cubical inches of sulphuretted hydrogene, all the hydrogene 
is set free, and a sulphuret of potassium containing one fourth 
of sulphur is formed, exactly the same as that produced by 
the immediate combination of sulphur and the metal. 
When sulphuretted hydrogene is employed in larger quan- 
tities, there is an absorption of this gas, and a volume is 
taken up about equal to the quantity of hydrogene disengaged, 
and a compound of sulphuretted hydrogene and sulphuret of 
potash is formed, which gives sulphuretted hydrogene by the 
action of an acid, nearly double in quantity to that given by 
the sulphuret of potassium. 
From a number of experiments I am inclined to believe 
that potassium and phosphorus, in whatever quantities they 
are heated together, combine only in one proportion, a grain 
of potassium requiring about •§ of a grain of phosphorus to 
form a phosphuret ; which when acted upon by muriatic acid, 
produces from to of a cubical inch of phosphuretted 
hydrogene. 
MDCCCX. L 1 
