284 M. Berzelius on the fOcr. 
ARTICLE XIV. 
Extract from a Memoir on the Composition of the Alkaline 
Sulphureis. By M. Berzelius. 
M. Berzeivs commences this paper with a history of the 
present state of our knowledge with respect to these compounds ; 
and he then proceeds to detail the experiments which he has 
performed to elucidate the subject, beginning with 
Experiments to determine whether the Sulphuret formed in the 
dry Way is a Sulphuret of the Oxide, or of the Metal. 
If sulphuret of potassium can exist, it is evident it ought to 
be formed when sulphate of potash is decomposed; and after the 
solution of the compound in water, the nature of the result must 
depend upon the formation of a sulphuret of potash or potas- 
sium. To verify this, I made use of a small apparatus with an 
enameller’s lamp, and so constructed that a current of hydrogen 
gas might be passed through it, while part of the apparatus was 
heated to redness by an argand spirit lamp. In this part one 
gramme (15-444 grains) of neutral sulphate of potash was intro- 
duced. This salt did not suffer any change for some time, but 
when the heat was raised, small red points were seen in parts 
which readily increased, and water was formed. The matter 
became black, and fused. The operation was continued as long 
as the gas introduced appeared to produce water, which was 
collected in muriate of lime. The salt, when cold, was of a fine 
cinnabar red colour ; it had lost 0°315 gramme, and the water 
produced weighed 0:335 gramme. The red mass was easily 
dissolved by water, which became of a very light yellow colour. 
It deposited some silica yielded by the glass, muriatic acid . 
evolved sulphuretted hydrogen with effervescence, and the 
solution was rendered slightly opaque by a little sulphur. 
Decomposed by muriatic acid, it gave with muriate of barytes 
0157 gramme of barytes, corresponding to 0:108 of sulphate of 
potash ; the 0°335 gramme of water produced contain 0298 of 
oxygen; but the sulphuric acid in one gramme of sulphate of 
potash contains only 0:275, and the potash 0-092 of oxygen. 
Then ifit be remembered that there remained at the close of the 
experiment one-tenth of the salt which did not appear to have 
been decomposed, it will appear that about two-thirds of the 
potash were reduced to potassium, and that the remaining 
one-third combined with the glass when it lost its sulphur, 
one portion of which combined with the potassium, and the 
other was carried off by the hydrogen in the state of a white 
