on the Nature of certain Bodies. 67 
From the general tenour of these various facts, it will not 
be, I trust, unreasonable to assume, that sulphur, in its com- 
mon state, is a compound of small quantities of oxygene and 
hydrogene with a large quantity of a basis that produces 
the acids of sulphur in combustion, and which, on account of 
its strong attractions for other bodies, it will probably be very 
difficult to obtain in its pure form. 
In metallic combinations even, it still probably retains its 
oxygene and part of its hydrogene. Metallic sulphurets can 
only be partially decomposed by heat, and the small quantity 
of sulphur evolved from them in this case when perfectly dry 
and out of the contact of air, as I found in an experiment on 
the sulphurets of copper and iron, exists in its common state, 
and acts upon potassium, and is affected by electricity in the 
same manner as native sulphur. 
4. Analytical Experiments on Phosphorus. 
The same analogies apply to phosphorus as to sulphur, and 
I have made a similar series of experiments on this inflam- 
mable substance. 
Common electrical sparks, passed through phosphorus, did 
not evolve from it any permanent gas ; but when it was acted 
upon by the Voltaic electricity of the battery of five hundred 
plates in the same manner as sulphur, gas was produced in con- 
siderable quantities, and the phosphorus became of a deep red 
brown colour, like phosphorus that has been inflamed and 
extinguished under water. The gas examined proved to be 
phosphuretted hydrogene, and in one experiment, continued 
for some hours, a quantity estimated to be nearly equal to 
four times the volume of the phosphorus employed was given 
K 2 
