400 Intelligence and Miscellaneous Articles. 
pyrites; but when the moistened place is touched with zine, sul- 
phuretted hydrogen gas is evolved, and the pyrites acquires a 
brownish colour. When iron is employed in place of zinc, no 
action appears to take place; nevertheless this is remarkably shown 
when fine powder of copper pyrites is mixed with fine powder of 
iron and treated with muriatic acid. Sulphuretted hydrogen gas is 
evolved in abundance; and if 2 parts of iron be taken to 1 part of 
pyrites, the latter is easily decomposed without the aid of heat, and 
the copper is precipitated, whilst in the absence of iron it is but 
slowly attacked by muriatic acid even when boiled. 
Other sulphurets behave in the same way as copper pyrites, and 
this comportment may therefore be made use of in ascertaining the 
presence of sulphur in them. For this purpose the author employs 
a cylindrical glass, about 23 inches in height and 1 inch in diameter, 
puts into it equal volumes of the specimen and iron powder (of 
each as much as can be taken up on the point of a knife), and 
pours over the mixture dilute muriatic acid to a depth of some lines. 
He then closes the glass with a suitable cork, which holds a strip of 
paper soaked in acetate of lead and then dried, in such a way that 
it passes across the whole width of the cork, and projects on each 
side when the glass is closed. With the following ores the reaction - 
for sulphur makes its appearance within one minute, the paper 
becoming yellow, brownish, or gray. 
Antimonite. Bornite. Gersdorffite (as also 
Pyrostibite. Stannine. amvibite). 
Argentite. Bismuthine. Cobaltine, colour pale 
Stephanite. - Galenite. yellow. 
Proustite. Geokronite. Pyrites, marcasite, lon- 
Pyrargyrite. Bournonite, colour of — chidite, kyrosite. 
Poly basite. paper pale yellow. Arsenopyrites. 
Aftonite. Boulangerite. Hauerite. 
Chalkosine. Plumosite. Sphalerite. 
Covelline. Dufrenoysite. Cinnabar. 
Tetraedrite. Jamesonite. Linneite. 
Tennantite. Plagionite. Nagyagite. 
Polytelite. Zinkenite. Tetradymite, colour 
Spaniolite. Kobellite. pale yellow. 
Chalcopyrite. Saynite. 
All these compounds, and of course also pyrrhotine (and sulphuret 
of iron and nickel), alabandine and Berthierite, which evolve sul- 
phuretted hydrogen, even by themselves, when treated with muriatic 
acid, show the above-mentioned coloration of the lead-paper within 
one minute. On the other hand, realgar, orpiment, and molybde- 
nite give no reaction. Sulphur itself, however, reacts in the way 
above mentioned. By this means very similar minerals may be 
distinguished at once, for example, Clausthalite and Galenite, for 
seleniuret of lead gives no reaction, chloanthite and arsenopyrites, &c. 
Iron powder is a carburet of iron (known in the shops as Ferrum 
aleoholisatum) ; of course it must be free from sulphur when employed 
in these experiments.—Gelehrie Anzeigen der hdnigl. bayer. Akad. 
der Wiss., and Journ. fiir Prakt. Chemie, |xxi. p. 146. 
