EE 
a ee 
Experinenis 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 on blowpipe, gave | 
Cartasil Me 24th Sestoies ge ee epee =e ere ath 
Water, a - ae ~ - . st as - 6.70 
esidue by incineration ; TEES 3 
_colour the same as the : 15.60 consisting of yf aectene cn mae } 7.10 
, _Alumine a.trace, 
~ 400.00 
Experiment 3d. A épeotinen of Plamntiag’ from Borrow- 
dale, of great purity, as judged by its external characters and 
mechanical Lhe rac was subjected. to the: blowpipe; the 
globules -immediately and in great number, 
attended ivewvionnlly 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. 
dull, of a brownish colour, and feebly tielocent; almost all 
of them were attracted by the magnet. The surface of ‘the 
heated part of the Plumbago was brownish. 
~The globules, though acted upon with great difionky by 
soda, and by potash, readily yielded to the compound flux, © 
ormed a limpid yellowish glass. A large globule, by 
repeatedly eating: it with carbonate of soda, and plunging it 
into water, became rough, and finally opened in the centre ; 
it then dissolved in nitro-muriatic acid. By gp acme the 
liquor to dryness, the yellow colour of the iron was¥ 
manifest ; acidulated water took it up, leaving a white ne 
stance like silex, floating in the liquor. — 
The coat Be of this Plumbago gave 
Garbon, - - - - - Senne orn 2 oS sep 
Water, - - - - weet SE Me Oe 
: Sees - - ri ia 
Residue by incineration, ak _ § Alam 1.00 
colour, yellowish brick } 10.4 consisting of Onides of iron end 3.60 
oot ; oa Py ("' 
100.00 
Experiment 4th. Animpure specimen of Plumbago fom 
the same locality, gave numerous and large globules ; some 
of the size of small shot; they readily formed; the majority 
Vor. : 14. 
