_Deutosulphuret_, _trisulphuret_ and _quadrisulphuret_. These may be formed by treating neutral solutions of manganese, or the recently precipitated oxide, by quadrisulphuret of lime. They are formed somewhat slowly and by considerable agitation with a smaller or greater proportion of the lime sulphuret. They are all light drab, and are reduced to the protosulphuret by heat. 35. _Sulphuret of chromium._ I have not had an opportunity of ascertaining whether chromium or its oxides combine with sulphur or not, though several attempts were made for that purpose. 36. _Sulphuret of uranium_. From the experiments of Bucholz it would seem that uranium may be combined with sulphur, but the proportions have not been ascertained. (An. de Chimie. 56--142.) 37. _Sulphuret of molybdenum._ From Bucholz and Klaproth’s analyses of molybdena it would seem that the native sulphuret consists of 60 metal and 40 sulphur; but it does not appear whether this should be considered as the protosulphuret or the deutosulphuret. If it is the protosulphuret the atom of molybdenum weighs 21, but if the deutosulphuret, the atom of metal weighs 42; and the atom of the sulphuret or molybdena must weigh either 35 or 70. 38. _Sulphuret of tungsten._ According to Berzelius, a sulphuret of tungsten may be obtained, by heating a mixture of tungstic acid and sulphuret of mercury in the proportion of 1 to 4, in a crucible. The mixture in his experiment was covered with charcoal and the crucible inclosed in another containing charcoal; the whole was then exposed to the heat of a furnace for half an hour. The sulphuret obtained was a greyish black powder; it was found to consist of 100 metal and 33¼ sulphur, or about 3 metal to 1 sulphur. Hence this must be the deutosulphuret if we consider the atom of tungsten to be 84; but considering the high degree of heat to which it was exposed, it would seem more likely to be the protosulphuret; if so, the atom of tungsten must be considered as 42 only, or half of the other number. 39. _Sulphuret of titanium._ No compound of titanium and sulphur has been formed. 40. _Sulphuret of columbium._ This combination is unknown. 41. _Sulphuret of cerium._ This combination is also unknown. SECTION 15. EARTHY, ALKALINE, METALLIC AND OTHER PHOSPHURETS. Phosphorus like sulphur is capable of being combined with several of the earths and metals as well as with other bodies; but the combination is not so easily effected, and the products are less interesting than those of sulphur: from considerations of these circumstances together with those of the expence and danger in making experiments on phosphorus we may account for, this class of bodies being as yet imperfectly known. Margraf in 1740 attempted to combine phosphorus with many of the metals; but his experiments were mostly unsuccessful.