ME. GEOEGE GOEE ON ELUOEIDE OE SILVEE. . 323 
strontium, barium, lithium, and sodium ; but, from various reasons, none of them could 
be used for the desired purpose. 
To ascertain more definitely the behaviour of argentic fluoride with chlorine at 60 c 
Fahr., I placed a platinum cup, containing 88*38 grains of the recently fused fluoride, 
in a dry glass bottle filled with 409*67 cub. centims. of perfectly dry and pure chlorine, 
the bottle being closed by a bung of vulcanized india-rubber coated with a mixture ot 
paraffin and lampblack, and inverted in mercury during thirty-eight days. No mercury 
entered, and the bottle was not corroded. A partial diminution of colour of the chlorine 
was produced by absorption of one third of the gas by mercury around the bung ; but 
the cup and silver-salt gained only *17 grain in weight. The saline residue was not 
even superficially whitened, and was found to be almost entirely soluble in water. 
Aime* passed chlorine over fluoride of silver at 60° Fahr. in glass vessels coated with 
caoutchouc ; the caoutchouc was acted upon, and hydrofluoric acid produced. 
To try the effect of a higher temperature, a stoppered glass bottle of 286*77 cub- 
centims. capacity ( = 13*38 grains of chlorine) was employed, its stopper being smeared 
with traces of very pure lampblack to make it more gas-tight. The platinum cup con- 
tained 70*77 grains of recently fused argentic fluoride, and was supported in the upper 
part of the bottle by a platinum wire. The mouth of the bottle was immersed in mer- 
cury, and the stopper secured. The bottle was kept at a temperature of 200° to 230° 
Fahr. during eleven days ; the yellow colour of the gas was not then perceptible, it 
was further heated to the same temperature during four more days ; no ingress of 
mercury or visible leakage took place, nor did the bottle become at all corroded. A 
crust of chloride of mercury formed around the stopper. After standing forty-eight 
hours at 60° Fahr., the neck of the bottle was broken under mercury, strong rarefaction 
was found, and the mercury rose rapidly until the bottle was about half full. The 
residuary gas was then yellow, and was wholly absorbable by mercury. The residue in 
the platinum cup was superficially white, and showed no appearance of containing che- 
mically combined platinum. By heating the cup (loosely covered with a platinum lid) 
gradually to redness, no special odour or evolution of gas was perceivable ; a trace of 
effervescence took place, such as always occurs with fluoride of silver on being fused in 
the air, and a loss of weight of *39 grain occurred. The crust from the mouth of the 
bottle was found by analysis to contain 7*914 grains of chlorine, and no hydrofluoric 
acid. After dissolving the fluoride in the cup by hot water, and the metallic silver from 
the residue by dilute nitric acid, about *80 grain of argentic chloride ( = *2 grain of 
chlorine) was found. The cup after heating to redness had lost *19 grain. From these 
results it is manifest that fluoride of silver heated to 230° Fahr. in a platinum vessel in 
dry chlorine during fifteen days, suffers only a minute superficial decomposition, and does 
not corrode the vessel as it does at a low red heat. 
* Gmelix’s Handbook of Chemistry, vol. ii. p. 359 ; Annales de Chimie et de Physique (1833), vol. It. p. 443 ; 
Poggendokff’s Annalcn, Leipzig, vol. xxxii. p. 576; Journal fur praktische Chemie, vol. ii. p. 469; Liebig's 
Annalen (1835), vol. xvi. p. 174. 
