Chemistry. 103 
3. Atomic Weight of Iron, (Journ. fir Prakt. Chem., xxxiii, p. 1.) 
—The atomic weight of this metal has lately been the subject of in- 
vestigation by Swanserc, Noxtin, Berzetivs, Expmann and Mar- 
CHAND, and all agree by different methods in making it 350, oxygen = 
100 or 28, hydrogen =1. This is nearly 1 greater on the hydrogen 
scale than that adopted in the recent works on chemistry by Kane, 
Granam, &c. wf. 
4, New Metals.*—There have been three new metals lately discov- 
ered,—Pelopium, Niobium and Ruthenium ; the first two were procu- 
red from the Bavarian Tantalite by Prof. H. Rose, and the latter was 
found associated with the ore of platinum by Prof. Craus. Pelopium 
and Niobium exist in the mineral under the form of Pelopic and Niobic 
acids. (Comptes Rend., Dec. 1844.) They resemble the tantalic or 
columbic acid so closely in all their properties, that it becomes difficult 
to separate them from each other. Prof. Rose has however obtained 
the Niobie acid perfectly pure, and the greatest difference between it 
and columbic acid appears to be, that it forms when heated with char- 
coal and chlorine, a chloride that is colorless, infusible and very slightly 
volatile, whereas the tantalic acid affords a chloride yellow, very fusible 
and volatile. 
The Niobium is readily obtained in its metallic state, by submitting 
the chloride to the action of dry ammonia, and applying heat, when 
the metal is reduced with the disengagement of the hydrochlorate of 
ammonia. 
The Ruthenium discovered by Prof. Cavs, (Chem. Gazet., Feb. 
1845,) as already stated, is associated with native platinum, and is 
procured from what is called the platinum residue, (the residue afier 
treating the platinum ore with nitromuriatic acid.) It is first fused 
with nitre at a red heat for about thirty minutes, and the fused mass 
treated with water and dilute acids, which extract the osmium and iridi- 
um ; the solid matter left is now fused with its own weight of nitre, and 
kept at a white heat for two hours; the mass is taken out, while still 
red hot, with an iron spatula, and after cooling reduced to a coarse pow- 
der, which is extracted with distilled water; so soon as the water be- 
comes clear, it is decanted. It contains rutheniate, chromate and sili- 
cate of potash. Nitric acid is added cautiously, until the alkaline re- 
action has disappeared ; by this means, oxide of Ruthenium and potash, 
and some silicic acid, are precipitated, as a velvet black powder; after 
been heretofore used for the production of sesquichloride of chromium, during 
which process the compound now first noticed by M. Peticor is also formed, 
and being mixed with the sesquichloride, has given rise to the discordant state- 
' ments which have been made regarding this substance.— Eds 
- * See Vol. xivitt, p. 400, of this Journal, f previ tice of these metals. 
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