188 Foreign Literature and Science. 
The variety examined was from the Palatinate. 
Silex 22) °- 
Magnesia ~ 29 
Alumine 17 
Lime 2 
Oxide of Tron 12 
Manganese 2 
Titanium 6 
Soda 6 
Water and 
CxtbonicAcid mane 
Two other varieties yielded 5.25 and 8 of titanium. 
It results from the researches of M. Peschier, 
1. That titanium forms one of the principal constituents 
of feldspath and serpentine. 
2. That the analysis of serpentine can be accurate only 
by employing the process used for rocks, so modified as to 
separate the titanium. 
5. Jeweller’s Powder.—T he powder commonly employed 
Saltpetre 
um 25 
Marine salt 35 
100 
But an examination of the colour now sold in Paris te 
jewellers, was found by M. Casaseca to consist of 
nic 
oxide of arse 2.135 gr. 
Alum, with base of potash 4.190 
: Marine salt _ : 13.560 
- Oside of iron and clay 0.115 
20,000 
