SCIENTIFIC SUMMARY. 
121 
greasy stain when rubbed between the fingers. It is comparatively soft, and, 
when scratched with a knife, falls off the mass in beautiful shining particles, 
having a metallic lustre, and not unlike powdered mica. The mineral is 
said to have been obtained in Ireland, near the surface, underlying about 
fifteen feet of peat. The following is a rough analysis of it : — 
Matter insoluble in HC1 and N0 5 9*5 
Ferric oxide 90*5 
100-0 
It is quite unacted on by the blowpipe, and contains no carbonaceous matter 
whatever. 
Wad: a Manganese Ore. — This ore has been described by Professor Henry 
How, in an article published in the “ Transactions of the Nova Scotian 
Institute of Natural Science.” It is a black earthy substance, which is found 
in rounded lumps and grains. It was sent from Parrsborough, and from 
another locality to the east of Halifax, where it is found in lumps mixed 
with stones ; the sample examined contained a great deal of water, and, 
when dried, 56 per cent, of binoxide of manganese, with the traces of cobalt 
which are usually found in this species. Neither of these would be valuable 
as ores of manganese, but they would probably serve as paints. Bog manga- 
nese is often mixed with bog-iron ore, and then forms deposits of a brown or 
chocolate colour, called ochres or mineral paints. The paints of Bridgewater 
and Chester furnish examples. In the first of these Professor How found 
only eleven per cent., and in the second about twenty per cent, of binoxide 
of manganese. It is said to be useless to send to (the English) market ores 
containing less than 65 per cent, binoxide. 
The A llotropic Conditions of Iron . — In a recent memoir laid before the 
French Academy, M. De Cizancourt put forward some very curious views 
relative to the constitution of iron. Metallic iron he believes to exist in two 
different states, just as phosphorus and sulphur do. The metal contained in 
the ores of the protoxide he terms Ferrosum, and those in the anhydrous 
peroxide ores he styles Ferricum. Black and grey cast irons are not physical 
conditions determined by a collection of identical molecules. They are 
simply ferricum, preserving a part of its properties, and depositing, when 
slowly cooled, the carbon with which the reaction had charged it while hot. 
In grey cast-iron ferricum is generally predominant ; in mottled cast-iron the 
two irons are present with their characteristics ; ferrosum gives the white 
portions and the carbon combined ; ferricum gives the grey portions with a 
carbon deposit. Malleable irons are formed of mixtures in varying pro- 
portions of two irons of different origin, both in the state of ferricum. 
Ferrosum in this state always partially preserves its hardness and power of 
returning to its original form. The variety found in the irons of commerce 
depends on the number of mixtures possible. — Vide Comptes Bendus, 9th 
October. 
A New Furnace has been described in the American Artizan. It consists 
of a smelting or reduction fire in combination with a combustion-chamber, 
ith tuyeres for admitting air, and openings in the division-wall. The com- 
