Experiments on Anthracite, Plumbago, &c. 103 
itated ; the latter was separated from the two former by 
caustic potash. No attempt was made to ascertain the rela- 
tive proportions of iron and manganese; this knowledge not 
being considered important. The presence of manganese 
was evidenced by the green colour of the alkaline fusion ; 
and a rose colour. when acid was added to the liquor. No 
allowance was made for the difference in the degree of ox- 
idation of the iron and manganese in the substances used, 
and the products obtained, as the amount was less than one 
per cent. where most abundant. 
The first experiments made with the globules, were with 
potash, and with carbonate of soda on silver, and on platina 
foil; with these agents I could not produce much effect, but 
by using a small quantity of carbonate of lime, carbonate of 
soda and borax, on platina foil; their fusion, whether they 
were coloured or colourless, opaque or transparent, was 
effi cted in a few minutes. 
Experiment Ist. A piece of the purest Anthracite of 
Lehigh, subjected to the blowpipe, presented numerous small 
white globules ; few were tinged with violet, and two or three 
were blackish ; the globules did not readily unite with one 
another ; however, by long continued heat, some of the’ 
globules were obtained of the size of the head of a small 
pin; the greater number of them were but feebly transiu- 
cent, and could be broken by a moderate force; others, 
though few in number, were transparent, hard, and not so 
brittle. The white globules were not magnetic, except 
when dark spots were present; the blackish ones were 
magnetic, and like the whole of them could be fractured by 
pressure. ‘The surface of the mass whitened, as observed 
in the ordinary combustion of this coal, and presented veins 
or layers of the matter of the white globules; showing that. 
the impurities of the coal were not regularly intermixed with 
its carbon, or, upon the supposition of its being fused carbon, 
that its production was extremely irregular. 
With the flux before mentioned, the different kinds of 
globules were melted without difficulty. By heating a cen- 
tigramme and a half of the globules in powder, for a long 
‘time, with caustic potash, about 2 of a centigramme of silex 
was obtained. It manifested itself by its gelatinous appear- 
ance before the water was driven off. 
