Intelligence and Miscellaneous Articles, 79 



The nature of the enveloping gas may, besides, be very approxi- 

 mately determined. In fact, if a few air-bubbles are let into the 

 vacuum-apparatus at the moment when the exhaustion is finished, 

 the orange-red coloration characteristic of hyponitric vapour appears 

 in the receiver : the gaseous sheath is therefore formed principally 

 of binoxide of nitrogen. 



What are the determining causes of the formation of the gaseous 

 sheath around the metal ? What is the nature of the influences 

 which afterwards keep up its adherence ? I am undertaking inves- 

 tigations bearing upon these questions*. — Gomptes Bendus de V Aca- 

 demic des Sciences, Nov. 10, 1879, t. lxxxix. pp. 783-786. 



AN EXPERIMENT ON SULPHUR. BY DE. THEODOR GROSS. 



In the following I take leave to make a brief communication on 

 an experiment with sulphur, by which I have obtained a substance 

 which, according to my judgment, is new, and cannot be further 

 analyzed by several of the most powerful chemical reagents. 



Some purest commercial milk of sulphur was mixed with linseed- 

 oil, in the proportion of one part of sulphur to not quite one part 

 of oil, and then gently heated in a very wide bowl. The mixture 

 swells up strongly, emitting disagreeable fumes, and leaves a black 

 porous mass behind in large pieces which will not ignite under con- 

 ditions under which sulphur by itself would burn briskly. The 

 black mass was then finely pulverized and, with pure concentrated 

 sulphuric acid, heated gently during several hours till it boiled- 

 After a brisk liberation of sulphurous acid, I obtained a liquid which 

 in its most concentrated state has the appearance of thick fluid 

 sulphur. More attenuated, it appears clear and pure yellowish red;, 

 still more diluted, brownish yellow. Into this diluted acid liquid, 

 sulphuretted hydrogen was passed, and thereby, at least in part, a, 

 bright-brown precipitate thrown down. This is soluble in sulphide 

 of ammonium, and also in hot potash-lye. On the other hand, even 

 a hot mixture of hydrochloric acid and chlorate of potass, dissolves 

 but little of it. 



When the precipitate is heated in air, the sulphur burns up, and 

 the residue is a black substance likewise very indifferent to inorga- 

 nic acids. This, on being heated in the combustion-boat in a tube 

 of difficultly fusible glass, with a. current of oxygen passing through 

 it, till the glass was bright- red-hot, proved fire-proof. Similarly 

 heated in chlorine it became first brown, and. after longer action 

 white ; and part of it was deposited as a sublimate immediately 

 behind the hottest place of the glass tube. By heating it in hydro- 

 gen the original black substance was then again obtained.. 



* This memoir will be inserted in extenso in the Annates de Chimie et de- 

 Physique. 



