338 Improved Process for obtaining Potassium. 
Arr. XVIII.—IJmproved Process for obtaining Potassium ; by 
Rosert Hare, M. D., Prof. of Chem. in the Univ. of Penn. 
Read before the Amer: Philos. Society, Dec. 7, 1838. 
In evolving potassium, agreeably to Brunner’s plan, I have sub- 
stituted for the luting usually employed to protect the iron bottle, 
a cylinder of iron, which is made to surround the bottle; alsoa - 
disk of the same metal, of a diameter and thickness equal to that 
of the cylinder. 
The disk is supported by bricks of kaolin. The bottle being 
vertical, the blast acts more equably on the surface of the iron, 
and the operator can, by additional fuel, protect any part from that 
undue exposure, to which the under surface is always liable, 
when the bottle is horizontal. 
The potassium is received into an iron tube, of which the bore 
is two inches in diameter. This tube screws at one end into the 
bottle, and at the other is closed by a perforated plug, terminating 
in asmall orifice. To this a leaden tube is fitted, which is so ad- 
justed by bending, as to cause the vapor resulting from the burn- 
ing of the gas, to go into the ash-hole. By these means the hy- 
drogen, being ignited as soon as it comes over, serves as an index 
of the success and progress of the process. In this way no resort 
to naphtha is in the first instance necessary. The potassium 1s 
extricated from the tube by cooling it by affusion of water, de- 
taching it from the bottle, and then closing the end thus exposed 
by a cap, in which a suitable conical female screw is wrought. 
The part of the tube containing the potassium is then made in ° 
a vertical position to occupy the axis of a cylindrical furnace, the 
end terminating, as above mentioned, in a tapering plug, being 
lowermost; and projecting below the bottom of the furnace. Be- 
fore the temperature reaches redness, globules of the metal begin 
to descend ; but to extricate the last portion, a white heat is requi- 
site. The potassium may be received in bottles, kept full of hy- 
drogen by a constant current, or in naphtha. The first portion, 
which descends before the temperature is high, can be more easily 
received without naphtha than the latter portion. 
