262 Chemical Nomenclature of Berzelius. 
each produce four at least, of which one only in each case is a base. 
Cobalt produces three, only one of which isa base. Iron gives 
three, two of which are bases. ‘Those sulphurets which are not 
bases and do not combine with other sulphurets, may without incon- 
venience be named according to their atomic constitution ; for ex- 
ample, bisulphuret,(46) trisulphuret, quadrisulphuret, persulphu- 
ret of potassium, &c : the last degree contains five atoms of sulphur, 
which composition it would be difficult to express in the name of 
the compound. ' The sulphurets of iron,(47) are—the ferrous sul- 
phuret, the ferric sulphuret, and the bisulphuret of iron: those of 
‘cobalt are, the cobaltic sulphuret, the sesquisulphuret, and the bi- 
sulphuret of cobalt: those of potassium, sodium, ammonium, &c. 
are the potassic, sodic, ammonic, &c. sulphurets, the bisulphuret and 
trisulphuret, quadrisulphuret, and persulphuret of potassium, sodi- 
um, ammonium, §c. By putting the name of the metal in the geni- 
tive case when the sulphurets are not bases, they are easily distin- 
guished from those which are. 
All that has been laid down in relation to the nomenclature of 
the compounds of sulphur, applies also to those of selenium and tel- 
lurium. Oxygen, sulphur, selenium, and tellurium constitute a dis- 
tinct class of bodies, which.form electro-negative compounds (aczds, 
sulphides, selenides, tellurides,) capable of combining with the elec- 
tro-positive compounds formed by the same bodies, (odes, sulphu- 
rets, seleniurets, tellurets,) to produce salts. I shall call this class 
of simple bodies, amphigen(48) bodies. The bases may be distin- 
guished as oxybases, sulphobases, selenibases, telluribases. 
COMPOUNDS FORMED BY CHLORINE, BROMINE, IODINE, AND 
FLUORINE. 
The four bodies just named possess these common properties. 
Their combinations with the electro-positive metals are neutral salts 
(46) This supposes the existence of five compounds of sulphur with potassium ; 
the first of these (the potassic sulphuret) is a base; the sulphur in the other four is 
in the ratio of 2, 3, 4 and 5, respectively. Berzelius admits two other sulphurets, 
containing sulphur in the proportions of 33 and 4%, to the quantity contained in the 
potassic sulphuret.— Trans. 
(47) Ferrous sulphuret,—protosulphuret of iron. The bisulphuret wid the 
same name inthe English nomenclature. The sulphur in the three sulphurets is in 
the proportion of 1, 14 and 2. Besides these Berzelius admits two subsulphurets of 
iron, containing one eighth and one fourth, respectively, of the quantity of sulphur 
in the ferrous sulphuret.— Zyans. 
(48) Amphigen; dupe, both, and yevycie, I generate; that is, producing com- 
pounds corresponding to both acids and bases.— Trans. 
