220 ANNUAL OF SCIENTIFIC DISCOVERY. 



fused. On cooling, the crucible is found to contain a hollow mass of 

 gray phosphuret of tungsten, lined upon the inside with the most bril- 

 liant crystals. These crystals have a dark steel color, with a remarka- 

 bly brilliant metallic lustre ; they are six-sided prisms, apparently of 

 the same form as gypsum ; their density is 5.207 ; they are perfect 

 conductors of the electric current. In contact with zinc, in dilute acid, 

 they evolve hydrogen, and in a solution of a salt of copper, they be- 

 come covered with metallic copper. The phosphuret is unchanged at 

 the temperature in which manganese fuses ; heated to redness in the 

 air, it undergoes scarcely any change ; heated upon charcoal in a cur- 

 rent of oxygen, it burns with great brilliancy, yielding a deep blue subli- 

 mate upon the coal. In the same manner it burns with fused chlorate 

 of potash ; acids exert no action upon it. Wright found the constitu- 

 tion of this compound to correspond with the formula P W 4 . Ann. 

 de Chemie und Phar. 



SULPHIDE OF NITROGEN. 



FORDOS and Gelis have published an elaborate investigation of the 

 sulphide of nitrogen, obtained by the action of ammonia upon perchloride 

 of sulphur, and concerning the constitution of which there has been 

 much doubt hitherto. The authors prepare the substance in question 

 by passing ammonia into a solution of perchloride of sulphur, in eight 

 or ten times its volume of bisulphide of carbon. In this process sal-am- 

 moniac is first deposited ; then a cochineal-red compound, partly solu- 

 ble in the liquid, but soon disappearing to give place to a brown matter, 

 which, in its turn, disappears. When this happens the process is fin- 

 ished. The liquid is now to be filtered and allowed to evaporate spon- 

 taneously, when the sulphide ofnitrogen crystallizes. The mother liquor 

 contains sulphur ; the mass on the filter is a mixture of sal-ammoniac 

 and sulphide of nitrogen, which may be separated by treatment with 

 boiling bisulphide of carbon. Sulphide of nitrogen, thus prepared, 

 presents transparent crystals of a beautiful golden yellow ; the crystals, 

 according to Nickles, belong to the right rhombic system. The pow- 

 der of the sulphide of nitrogen has a brilliant yellow color ; when rubbed 

 or struck with a hard body, it explodes with great violence ; brought 

 into contact with an ignited body, it fuses without explosion ; heated 

 in an oil bath to 157 C., the sulphide explodes, yielding nitrogen and 

 the vapor of sulphur. Sulphide of nitrogen has little or no odor, but it 

 strongly irritates the mucus membranes, when brought into contact 

 with them. In water it is insoluble ; alcohol, ether and turpentine 

 dissolve small portions of it ; bisulphide of carbon is its best solvent. 

 The composition of the sulphide of nitrogen was found to be expressed 

 by the formula N S^. Boiling water decomposes the bisulphide of nitro- 

 gen ; the reaction is expressed by the equation 



4NS 2 -f 15HO = S 2 O 2 ,NH 4 0-{-2 (S 3 s , NH 4 0) + NH 3 . 



Caustic potash in like manner produces decomposition ; the final prod- 

 ucts of action are expressed by the equation 



