Chem. [f. TRI- 5 + SULPHIDE.] A compound of an element or radical with three atoms of sulphur; e.g., boron trisulphide, B2S3; arsenic trisulphide, As2S3; potassium trisulphide, K2S3.
1866. Roscoe, Elem. Chem., xxiv. 207. Metallic antimony occurs native, but its chief ore is the trisulphide.
1888. Muir & Morley, Watts’ Dict. Chem., I. 516. Bismuth Trisulphide, Bi2S3, occurs native as bismuth glance.
1905. Jrnl. Chem. Soc., LXXXVIII. II. 245. Golden-yellow leaflets of arsenic trisulphide are formed.
