ME. GEOEGE GOES ON ELUOEIDE OE SILVEE. 
233 
thin platinum cup or muffle (fig. 4), made without solder, heated by means of a furnace 
(fig. 5), in which the substances could be raised to a high temperature without exposing 
them to contact with the products of combustion. A (fig. 5) is an open clay cylinder, 
B B is a perforated clay plate to receive the cup D. With the aid of this arrange- 
ment and a corrugated gas-burner, I have been able to electrolyze substances at the 
temperature of melted cast iron, and observe the phenomena taking place at the elec- 
trodes, and by means of additional arrangements have also collected the gases evolved 
at those temperatures without admission of air. 
On cooling melted fluoride of silver in an open platinum vessel, it effervesced on every 
occasion whilst solidifying ; and on remelting it out of contact with the gases of the burner, 
more gas was evolved as soon as it acquired a dull red heat. 100 grains of the brown 
salt, alternately heated to redness and cooled nearly to solidifying, thus, repeated iy 
during thirty-five minutes, lost 3 "86 grains in weight; and the residue, on solution in 
water, left 17 - 04 grains of silver, chiefly as a fine powder. A second 100 grains, kept 
at a dull red heat in an open crucible within the covered muffle during forty-five minutes, 
lost 2-47 grains, and yielded 12'22 grains of free silver. In a third experiment, 50 grains 
kept at just visible redness in a closely covered crucible in the closely covered muffle 
during 14 hour, lost only ’62 grain, and yielded 3 - 18 grains of free silver. In a fourth 
similar experiment, in which the silver-salt was partially exposed to the air during one 
hour, the quantity of silver set free was equivalent to about five-sixths of the total 
amount of fluorine present. The losses in all these experiments were due, 1st, to the 
Fig. 4. 
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