290 Hare’s Blowpupe. p 
Experiments on Magnesia. 
Silliman, page 110. ‘The same circumstances that ren- 
dered the operating upon lime difficult, existed in a still 
greater degree with respect to magnesia ; its lightness and 
pulverulent form rendered it impossible to confine it for a 
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 
consistency 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 compound flame; the escape of the water caused the 
vertex of the cone to fly off repeatedly in flakes, and the top 
of the frustrum that thus remained gave nearly as powerful 
a reflection 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 smk- 
ing could be expected. After a few seconds the piece be- 
ing examined with a magnifying glass, no roughnesses or 
earthy particles could be perceived on the spot, but a num- 
ber of glassy smooth protuberances whose surface was a per- 
fectly white enamel. ‘This experiment was repeated with 
the same success. May not magnesia then be also added 
to the table of fusible bodies ? 
Notwithstanding the previous publicity of these results 
obtained by my friend and myself, Dr. Clark in the follow- 
ing note, endeavors to convey an impression of the incom- 
petency of my apparatus to fuse lime and magnesia. Note 
5, page 46. “ Professor Hare in America could not ac- 
complish the fusion either of lime or magnesia by means of 
his hydrostatic blowpipe. See Annales de Chimie, tome 
45 page 126.” But why overlook Silliman’s experiments. 
It is moreover strange that an English writer should refer 
his readers to the French Annales in preference to a Lon- 
don magazine, for a memoir which he knew to be published 
in both.* 
*T mentioned above that I had lately fused a piece of oyster shell lime. 
It was exposed to the fame within an envelope of platina foil which was 
soon reduced toa fluid globule. The application of the heat being suspend- 
