106 Experiments on Anthracite, Plumbago, xc. 
ef them were Sra shining, and of a light greenisi- 
yellow, re dark coloured; and some of them were 
dull anny. “The dark globules, as well as the surface of 
the mass of Plumbago exposed to the flame, was attracted by 
the magnet ; some of the light coloured ones were affected 
by the magnet, but only at th point where they ha been 
attached to their support, owing to particles of the support 
adhering to them. During the combustion of the Plumbago, 
there were —_—, scintillations ; the heated surface of 
the mass was brownis 
and milky when cold. 
were also fused; they were brownish when hot, and greenish 
when cold. _They were aeted upon with great difficulty by 
¢austic potash, and by carbonate of soda, 
“The Lar of this Plumbago gave 
Water, - - eee - Sc - ee B53 
, Silex, ast = 10.10 
: “yel- > onsist ide of iron 
ga dt cea iia Bade 
Loss, 10 
3 100.00 
Experiment 5th. A specimen of Plumbago remarkably 
pure from near Bustietown, Penn was tried with the blow- 
pipe. The "tases were formed with difficuity, probably 
owing to its foliated texture, the fused parts spreading over 
the surface. The colour in places was white and translucent, 
ip others so dark as to be almost black. 
With the flux before mentioned, the fused matter was re- 
duced to a transparent glass. 
The analysis of this Plambago gave 
ae ae ee eee * = 
j - Bios Sil, 2 
Residue by incineration, 7 Oxides of iron and 
colour light brick red, {50 Gommisting of manganese, : < 
