486 
SECOND REPORT- 1832. 
Spinell Mg-f A1 
Pleonast 
Gahnite 
Mg 
Fe 
• 
Zn 
Mg 
+ A1 
+ A1 
Chromite of iron 
Fe 
Fe 
Mg 
Franklinite 
Zn 
*■ + * 
Y + i 
Fe 
Cr 
• • • 
A1 
[Mn 
Magnetic iron Fe + Fe 
• ••• 
General formula R -f R 
Abich has found that all these compounds can be formed 
artificially by the moist way *. 
Hornblende and augite. —A late Memoir of Gustaf Rose, in 
which he proves the identity of hornblende and augite, has 
opened out a new field for crystallographic research, and has 
confirmed the conclusion to which other researches had led, 
that crystalline form can no longer be depended on as a cha¬ 
racteristic of mineral compounds. To this beautiful Memoir f 
I can only allude in this place, and recommend it strongly to 
the attention of the reader. 
Artificial mineral compounds. —A similar observation of Mit- 
scherlich, connecting together the slags of the iron smelting 
furnaces and the pyroxenes (augites), is highly deserving the 
notice of the mineralogist. These slags are often crystallized, 
have the form of augite, and are represented by the same che¬ 
mical formula. Berthier, to whom mineral chemistry owes so 
much, has formed silicates of manganese as well as of iron in his 
furnaces, and obtained them regularly crystallized. Those who 
have access to his elaborate papers in the Annales de Mines, will 
recollect many other chemical compounds in atomic proportions, 
formed by fusing together the several constituents. 
Chemical analysis. —A valuable present has lately been made 
to the analytical chemist by the publication of Prof. H. Rose’s 
work on chemical analysis, a translation of which into English 
has been executed by Mr. Griffin. Two editions in the ori¬ 
ginal German have already been published, and a third is in 
progress. These later editions are greatly improved and en¬ 
larged. 
Systems of Chemistry. —Of the systems of chemistry in pro¬ 
gress in foreign countries, the reader is probably already ac¬ 
quainted with the French edition of Berzelius’s Lehrbuch , with 
* Poggendorf’s Annaten 3 xxiii. p. 305. 
f Id. xxii. p. 321. 
