348 M. Berzelius on the [Nov 
composed of one atom of metal and an atom of oxygen. These 
combinations agree with both modes of reckoning the atoms, 
and the methods of obtaining them are such as necessarily pro- 
_duce compounds of determinate proportions. 
As to those in which 1 atom of potassium is united to 7 or 9 
atoms of sulphur, they prove incontestably the justice of the 
opinion, that potash contains not | atom but 2 atoms of oxygen; 
for in the first case, these compounds would contain 31 and 41 
atoms of sulphur, and we cannot admit of half atoms. I am, 
however, far from regarding the thing as proved by these com- 
pounds, especially since we know that magnetic oxide of iron, 
both natural and artificial, is composed of two different oxides of 
iron, and it is consequently possible that the above combinations 
may contain two degrees of sulphuration, which might be either 
entirely similar to the two compounds A S’ and K 8°, or at least 
very nearly resembling them. 
I ought not, however, omit to observe, on this occasion, that 
in all my experiments, with very few exceptions, the quantity of 
sulphur has very little exceeded that indicated by calculation. 
This happens either because the atom of sulphur is actually 
heavier than it has been reckoned, or which seems more proba- 
ble, because the last portion of sulphur is expelled with diffi- 
culty. 
III. Combination of Sulphuretted Hydrogen with Potash. 
I have already shown that the subcarbonate of potash decom- 
posed by sulphuretted hydrogen gas, gives a hepar of a bright- 
yellow colour, which crystallizes on cooling, and which has a 
crystalline fracture like that of salts. 20°87 grammes of sub- 
carbonate, subjected to a dull red heat, were exposed to a cur- 
rent of sulphuretted hydrogen gas until no water was produced ; 
it was not accompanied by sulphur. The excess of sulphuretted 
hydrogen gas escaped without having undergone any alteration, 
and merely mixed with carbonic acid gas: the action of the heat 
was continued for about six hours. The fused mass was in a 
state of continual ebullition, which was undoubtedly caused by 
the evolution of carbonic acid gas and aqueous vapour; for when 
at length it ceased, no further disengagement of water occurred. 
Gas was constantly passed through the apparatus until it became 
cool. The compound was of a pale lemon-yellow colour; it 
was crystallized in large brilliant plates; it weighed 22:28 
grammes, was very deliquescent, and dissolved in water, to 
which it communicated a pale-yellow colour. 
20°87 grammes of carbonate of potash contain 11-816 grs. of 
potassium, which quantity remains of course in the 22°28 of sul- 
huret of potassium obtained. It was, therefore, united to 
10°464 gr. of sulphur; but 
11°816 ; 10°464 :: 100 : 885 
