210 Progress of Foreign Science. 
small apparatus blown at the enameller’s lamp, and constructed 
so that he could pass through it a stream of hydrogen gas, 
while one part of the apparatus was heated to redness by an 
Argand lamp with spirit of wine. Into this part was intro- 
duced 1 grain of neutral sulphate of potash. This salt expe- 
rienced for some time no alteration; but when the heat became 
more intense, there were perceived red points, which extended 
quickly, and water began to be formed. Soon the substance 
became black, and entered into fusion. The operation was 
continued as long as the gas introduced seemed to produce 
water, which was condensed over muriate of lime. The salt, 
when cool, presented a mass of a very fine cinnabar-red ; and 
the glass had been visibly acted on. This compound had lost 
0.315 grains, and the water which was formed weighed 0.335 
grains. The red mass was easily dissolved in water, which 
assumed a hue very faintly yellowish. There was deposited 
some silica, proceeding from the glass, and muriatic acid dis- 
engaged sulphuretted hydrogen with effervescence; at the 
same time the liquid seemed slightly clouded with a little sul- 
phur. Decomposed by muriatic acid, it afforded with muriate 
of barytes 0.157 grains of barytes (sulphate of barytes), cor- 
responding to a portion of 0.108 grains of sulphate of potash. 
The 0.335 grains of water produced contain 0.298 of oxygen; 
but the sulphuric acid in | grain of sulphate of potash, contains 
only 0.275, and the potash only 0,092 grains of oxygen. Now 
if we consider that there remained at the end of the experiment 
+f; of the salt which appeared not to have been decomposed, we 
shall find that about % of the potash had been reduced into 
potassium, and that the remaining + had combined with the 
glass on losing its sulphur, a portion of which united to the 
potassium, and the other accompanied the hydrogen under the 
form of a white vapour, which caused the excess of the loss of 
salt beyond what was found in the oxygen of the water, 
2. This experiment would already prove that the hepar con- 
tains sulphuret of potassium, since, were the combination of sul- 
phur with potash possible, hydrogen gas could not certainly re- 
duce this alkali at so moderate a heat; but the loss which the 
elass had suffered, throwing some uncertainty on the result of this 
experiment, M. Berzelius made choice of another means. He 
reduced, in an apparatus perfectly similar, sulphate of potash by 
sulphuretted hydrogen, and continued the operation as long as 
water escaped with the gas, which continued for 3 hours ; at 
the same time there was deposited some sulphur ; but as soon as 
no more water is formed, the sulphur separates no longer from 
the gas. He let the operation go on for a quarter of an hour 
after the last period. 
One grain of sulphate of potash was converted in this man- 
ner into 1.11 grains of hepar. Very liquid and black while it 
