474 
SECOND REPORT— 1832. 
which gives for the atom tellurium 8*028, and of telluric acid 
11*028. 
Persulphuret of tellurium.-— Besides the sulphuret of tellu- 
rium T formerly known, Berzelius has formed a persulphuret T, 
corresponding to the new acid T. When a solution of telluric 
acid in water is saturated with sulphuretted hydrogen and set 
aside, a metallic-looking substance gradually deposits itself on 
the sides of the glass, while the liquid rests clear: this is the 
sulphuret in question. 
Chlorides of tellurium. —-Rose has also lately examined the 
chlorides of tellurium. When the metal is gently heated in 
chlorine gas, a white crystalline compound is formed, consist¬ 
ing of 
Chlorine 52*13 — 2 atoms! __ 9 T 
Tellurium 47*87 = 1 atom j 
It has much resemblance to the solid chloride of selenium. 
When the metal is strongly heated in the same gas, violet va¬ 
pours are formed, which condense into a black deliquescent 
mass. When freed as much as possible from bichloride, this 
substance was found to consist of 
Chlorine 37*77* = 1 atom! _ ri a. T 
Tellurium 62*23 = 1 atom] — 
It is interesting to observe by what analogies the chlorides 
of sulphur, selenium, and tellurium are connected, and by what 
differences they are distinguished. Of sulphur we have one 
chloride (Cl+ 2 S), which is analogous in every respect to the 
dichloride of selenium (Cl+ 2 Se); but here the analogy stops, 
and we have no direct link to connect it with the chlorides of 
tellurium. But the solid chloride of selenium (2C1 + Se), is 
connected by an analogy equally close and striking with the 
bichloride of tellurium (2 Cl + T.) These three bodies there¬ 
fore form a natural group connected together, like the com¬ 
pounds of phosphorus, arsenic, and antimony, by many similar 
properties, and yet differing in others so widely as to afford 
the analytical chemists ample means for detecting the presence 
of each. 
Artificial Ultramarine. —A discovery likely to prove of con¬ 
siderable use in the arts is the manufacture of ultramarine by 
a process founded on the analysis of the native substance by 
Clement Desormes, and of a similar substance found on the 
lining of a furnace by Vauquelin. According to Gmelinf this 
* Poggendorf’s Annalen, xxi. p. 442. 
f Ann. de Chimie, xxxvii. p. 409. 
