186 Scientific Intelligence. 
the Veratrum sahadllla^ an alkaline matter capable of crystallising, 
and endowed with an excessive bitterness. Their experiments 
upon this substance have not yet been completed. Journal de 
Physique^ Aout, p. 155. 
14. Dr Clarke on the Alloy of Lead ami Platinum. — If pieces 
of platinum and lead be placed beside each other, and exposed 
to the heat of the blowpipe, there will be seen, when the plati- 
num is heated, a beautiful play of blue light upon the surface 
of the lead, becoming highly iridescent before it melts. 
15. Experiments on Rock-Ciystal and Glance-Coal exposed to 
the Heat of the Alloy of Tin and Platinum. — When rock-cry- 
stal In powder is wrapt up in tin and platinum foil, and melted 
as in Fox’s experiment, the fracture of the alloy is closer grain- 
ed and has less lustre, than when the metals are melted by 
themselves : the combination of part of the silica perhaps occa- 
sions this difference of fracture. When a small piece of rock- 
crystal is heated in this way, there is an appearance of fusion 
on its surface. There is no appearance of fusion in glance-coal 
when heated in this manner, but it becomes so hard as to scratch 
glass. Dr Clarke heoXed plumbago with the gas blowpipe, and 
minute globules of transparent glass were formed on the sur- 
face ; but since plumbago contains iron, it would have been 
better to have tried glance-coal, as it seems very refractory, and 
as most other substances have yielded to the gas blowpipe. If 
heated in the air, it would likely be dissipated ; but it might be 
kept in a globule of platinum in fusion, and it would be seen 
whether it melted with this heat, or to what degree of hardness 
it was brought. 
16. Boracic Acid found In the Crater of Volcano. — M. Lucas 
finlor has announced, that he has discovered, among the saline 
concretions which cover the sides and the ground of the crater of 
Vulcano, a scaly and pearly crust, wLich, from its bitter taste, 
appeared to him to be boracic acid. This idea w'as completely 
confirmed by the experiments of D. Gioachino-Arrosto, a well 
informed chemist in Messina. Ann. de Chlm. et de Phys. 
tom. xi. p. 44. 
17. Improvement on the Gas Blowpipe. — It has been announ- 
ced in the Journal de Physique for July 1819, that M. Berze- 
