110 On the Oxi-hydrogen Blow-pipe. 
was delicate and the determination of the result might be diifi- 
cult,) that, as the cylinder was held in a perpendicular position,’ 
if the lime did really melt, the column must sink and become, at 
least to a degree, blended with the supporting mass of lime. 
When the compound flame fell upon the lime, the splendour of 
the light was perfectly insupportable by the naked eye; and when 
viewed through deep-coloured glasses (as indeed all ‘these experi- 
ments ought to be), the lime was seen to become rounded at the 
angles, and gradually to sink, till in the course of a few seconds 
only a small globular protuberance remained, and the mass of. 
supporting lime was also superficially fused at the base of the 
column, through a space of half an inch in diameter. The 
protuberance, as well as the contiguous portion of lime, was con- 
verted into a perfectly white and glistening enamel; a magni- 
fying glass discovered a few minute pores, but not the slightest 
earthy appearance. This experiment was repeated several times, 
and with uniform success ; may not lime therefore be added to’ 
the list of fusible bodies ? 
Magnesia.—The same circumstances ‘that rendered the ope- 
rating upon lime difficult, existed in a still greater degree, with 
respect to magnesia; its lightness and pulverulent form rendered 
it impossible to confine it fora moment upon the charcoal ; and 
as it has very little cohesion, it could not be shaped by the knife, 
as the lime had been. After being calcined, at full ignition, in 
a covered platinum crucible, it was kneaded with water, till it 
became of the consistence of dough. It was then shaped into a 
rude cone as acute as might be, but still very blunt; the cone was 
three-fourths of an inch long, and was supported upon a coiled 
wire. 
The magnesia thus prepared, was exposed to the canal? 
flame: the escape of the water caused the vertex of the cone to, 
fly off in repeated flakes, and the top of the frustum, that ‘thus 
remained, gave nearly as powerful areflection of light as the lime 
had done: from the bulk of the piece (it being now one-fourth 
of an inch in diameter at the part where the flame was applied) 
no perceptible sinking could be expected. After a few seconds, , 
the piece being examined with a magnifying glass, no roughnesses 
or earthy particles could he perceived on the spot, but a number of 
glassy, smooth protuberances, whose surface was a perfectly white 
enamel, This experiment was repeated with the same success. 
May not magnesia, then, be also added to the table of fusible, 
bodies? « 
Yitria—was the only remaining primitive earth; but no speci- 
men of it could be obtained. 
Perhaps then we shall be justified in saying, in future, that the: 
primitive earths are fusible bodies, although not fusible in fur-, 
naces, 
