Miscellanies. 387 
sensible. Whenever, also a piece of metal moves near a magnet, so 
as to intersect the magnetic curves, electricity is evolved, according 
to very simple laws.—Phil. Mag. April, 1832. 
13. New lamp.—In the course of the first meeting, at York, of 
the British association for the advancement of science, the Rev. 
Wm. V. Harcourt showed a lamp constructed on a new principle, 
and explained the principle and construction of it. He gave it the 
name of an oi gas lamp; tiot because it was lighted by gas formed 
at a temperature below that of flame (for this is commen to all lamps) 
but because, as in the gas lights of the streets, the gas issues from 
a reservoir, and owes the perfection of its combustion not to an as- 
cending current of hot air, but to the force with which it is propelled 
from the reservoir and carries the air along with it. It differed, how- 
ever, from the common gas lights in these circumstances :—that the 
reservoir formed part of the burner; that the gas was formed as it 
was consumed ; and that it was propelled not by a vis a tergo, and 
in a state of condensation, but by the expansive force of its own 
heat. In consequence of this circumstance, the eurrent of the gas- 
eous jet was more rapid in proportion to the quantity of water gon- 
tained in it than in the common gas light, whilst it was also at 
higher temperature, so that it could issue with a greater ae 
without being liable to blow itself out. The practical difficulty con- 
sisted in the obtaining a steady supply of light, especially with the 
cheap oils. This difficulty had been in a great measure surmount- 
ed; but the instrument was still imperfect.—Jdem. ; 
14. Pelokonite, a new mineral.—lts name comes from #shi¢, 
brown, and xévic, dust, in allusion to the color of its streak. Form 
unknown ; cleavage none; fracture conchoidal ; color bluish-black ; 
streak liver-brown ; eae ; lustre vitreous, feeble 5 3 tenacity not 
great; hardness 3-0; sp. gr. 2-50—2°56. It is very solobie i in mu- 
riatic acid,—the solution having a pistachio green color. It is found 
in the Terra Amarilla and the Remolinos, in Chili, along with cop- 
per green malachite, and another unknown blackish-brown mineral 
with a yellow streak. ‘The above description is by Richter, of Frey- 
berg.—Jameson’s Journal. 
a Atum or Mino, 4 SULPHATE oF ALUMINE.—Ia fs 
eer om framstegen I Physik och Chemie afgifven den 31 
