Experiments on Anthracite, Plumbago, §c. 105 
Another specimen from the same locality, whose colour 
was a little different, being of a deeper black, and which was 
not tried with the blowpipe, gave 
Carbon, - - > - - - - - - ~ > 47.70 
Water, - > 2 = > - ° - - - 6.76 
Silex, a s 8.50 
Oxides of iron and , 7.10 
manganes?, 
Alumine a trace, 
Residue by incineration, 
colour the same as the > 15.60 consisting of 
former, 
aera 
160.00 
Experiment 3d. A specimen of Plumbago from Borrow- 
dale, of great purity, as judged by its external characters and 
mechanical properties, was subjected to the blowpipe; the 
globules began to form immediately and in great number, 
attended occasionally by scintillations, owing to the combus- 
tion of iron; the globules were small ; the greater part of 
them were black, opaque, and of great lustre; others were 
dull, of a brownish colour, and feebly translucent; almost all 
of them were attracted by the magnet. The surface of the 
heated part of the Plumbayo was brownish. 
The zlobules. though acte’ upon with zreat difficulty by 
soda, and by potash, readily yielded to the compound flux, 
and formed a limpid yeliowish glass. A large globule, by 
repeatedly heating it with carbonate of soda, and plunging it 
into water, became rough, and finaily opened in the centre ; 
it then dissoived in nitro-muriate acid. By evaporating the 
liquor to dryness, the yellow colour of the iron was very 
manifest ; acidulated water took it up, leaving a white sub- 
stance like silex, floating in the liquor. 
The analysis of this Plumbago gave 
Garbon, > > > - - - - - - - - 88.37 
Waiter, - - 2 = ° - - - - - > 1.23 
Silex, - > 5.10 
Residue by incineration, Alamine, - 1.00 
colour, yellowish brick > 10.4 gonsisting of < Oxides of iron and 3.60 
red, manganese, : : 
\, Loss, 70 
100.06 
Experiment 4th. Animpure specimen of Plumbago from 
the same locality, gave numerous and large globules; some 
of the size of small shot; they readily formed : the majority 
Vor. X.—No. 1. 
