Intelligence and Miscellaneous Articles* 553 



It may therefore be regarded as composed of 



One equivalent of chloride of mercury = 238 



One „ chloride of sulphur = 52 -290 



A proof of the probability of this view of its nature is the fact al- 

 ready stated, that it may be prepared by the direct action of these 

 compounds on each other. — Journal de Pharmacie, Sept. 1839. 



FORMATION OF SULPHURIC ACID. BY M. H. ROSE. 



It is well known that sulphuretted hydrogen gas reduces the 

 higher oxides of some metals to a lower state of oxidation. It is 

 generally admitted that this reduction is derived from the formation 

 of water ; and the simultaneous separation of sulphur seems to au- 

 thorise this opinion. A considerable time since, I observed that in 

 some of these cases sulphuric acid was produced, but which could 

 not be detected in others. This fact gave rise to the following ex- 

 periments : — 



Sulphuretted hydrogen gas does not produce sulphuric acid in a 

 cold solution of sesquioxide of iron. If this oxide, recently pre- 

 cipitated, be dissolved in acetic acid, and a great excess of acetic 

 acid be added to the solution, in order to avoid, as much as pos- 

 sible, the production of sulphuret of iron by the current of sulphu- 

 retted hydrogen, no sulphuric acid is found in the solution ; nor is 

 there any formed if the solution be heated during the introduction 

 of the gas. 



If sulphuretted hydrogen gas be passed into a neutral solution of 

 chloride of iron, or acidified by hydrochloric acid, sulphur only is 

 separated, without the production of sulphuric acid. If, however, 

 the solution be heated while the gas is passing into it, sulphuric 

 acid is formed in the solution, the production of which, under these 

 circumstances, seems worthy of observation. It also takes place 

 when a solution is used which is prepared by treating iron with hy- 

 drochloric acid and adding nitric acid, and in employing a pure so- 

 lution of chloride of iron, and which contains no free chlorine, pre- 

 pared by heating pure iron in chlorine gas. These solutions had hy- 

 drochloric acid added to them, in order to prevent the separation 

 of sesquioxide of iron by ebullition. The formation of sulphuric 

 acid cannot therefore be attributed, in these circumstances, to the 

 admixture of a small quantity of nitric acid. "When sulphuretted 

 hydrogen is employed to determine the proportion of sesquioxide of 

 iron contained in a mixed solution of sesquioxide and protoxide, by 

 the quantity of sulphur precipitated, the solution must be used cold. 

 . — Journal de Pharmacie, Aout, 1 839. 



SULPHURETTED HYDROGEN ACTION ON SOME SALTS OF 



^ POTASH. BY H. ROSE. 



When sulphuretted hydrogen gas is passed into a dilute solution 

 of chromate of potash, acidulated with acetic acid, no sulphuric acid 

 is formed ; the same is the case when hydrochloric acid is employed 

 instead of the acetic, provided the solution be so dilute that the acid 



