324 = Analysts of the New-Jersey Ores of Zinc. 
is effected by dissolving it in muriatic acid, precipitating the 
solution by an alkaline carbonat, treating the wet precipitate 
by acetic acid to excess, evaporating to dryness by a gentle 
heat and removing the acetats of zinc and manganese by 
water; the calcined residuum is found to be the pure tri- 
toxid of iron. As to the zinc and manganese, they are sep- 
arated by the processes pointed out above. 
Ina specimen from Franklin there were found : 
Perexid of iron, - - - - 0,66 
Red oxid of manganese, - 0,16 
Oxid of zine, =) Oe 
99 
As the Franklinite acts upon the magnetic needle, the 
iron cannot be in the state of per-oxid, but is probably 
oxidized in the second degree. It is evident that the man- 
ganese is at least, in the state of deutoxid, because the min- 
eral has a brown powder, gives with muriatic acid the 
odour of chlorine, and its muriatic solution contains the iron 
entirely in the maximum state of oxidizement. It is obvi- 
ous that during the solution the two oxids react upon one 
another, and that the oxid of iron passes to the maximum 
by taking away the oxigen from the oxid of manganese, 
which is, on the contrary, reduced to a minimum. 
For the purpose of verifying the result of the humid anal- 
ysis, I made the following trials :—10 er. of the franklinite 
were heated in a crucible brasqué without addition at the 
temperature proper for the assay of iron. A metallic but- 
ton was obtained, to which adhered a very light greenish 
scoria; the whole weighed 5 gr. 65; the button was of 
an iron grey, hard, but impressible by the file, and capable 
of assuming a beautiful polish ; it flattened under the ham- 
mer, and was broken with difficulty 5 its fracture was grey 
and granular, the grains being crystalline; it was analysed, 
and found to be an alloy of iron and manganese, without a 
particle of zinc ; the loss in the experiment then represents 
the oxid of zinc, and the oxigen combined in the mineral 
with the tron and manganese. 
