238 
MS. GEORGE GORE ON ELUORIGE OE SILVER. 
With Nitrous Anhydride . — Nitrous anhydride from a mixture of starch and partly 
diluted nitric acid, perfectly dried by passing through a Liebig’s condenser and then 
over burnt chloride of calcium, was passed during two hours over a weighed amount of 
the previously fused salt at a low read heat in platinum vessels. The salt was wholly 
converted into chloride, evidently in consequence of my having employed chloride of 
calcium as the drying agent. 
With Peroxide of Nitrogen. — Highly dried and hot nitrate of lead in powder in a 
glass retort was heated until the retort was full of a red-brown vapour ; the vapour then 
passed over 69 - 68 grains of gently warmed fluoride of silver (which had been previously 
fused) in a platinum boat within the long platinum tube (used in the nitric oxide expe- 
riment) during seventy minutes. The salt gained 4-70 grains in weight, but exhibited 
no signs of decomposition ; by heating the residue to near redness it freely evolved brown 
fumes of peroxide of nitrogen. Gently warmed argentic fluoride, therefore, is not decom- 
posed by peroxide of nitrogen, but only absorbs it. The residuary salt of this experiment 
was now heated just to redness in the same apparatus, and the vapour similarly prepared 
passed over it during IT hour. During the whole of the first hour fumes were evolved 
which corroded dry glass freely : the corrosive action then ceased. After the process the 
boat was empty of silver-salt, and much reduced silver (more than 24 grains) was found 
in the boat and tube. The undecomposed portion of the salt had passed out of the boat 
by capillary action. The results were probably due to moisture still remaining in the 
nitrate of lead. 
Fluoride of silver dissolved in hot concentrated nitric acid. 
With Hydrofluoric Acid. — The behaviour of the brown salt with liquid anhydrous 
hydrofluoric acid has been already described (Phil. Trans. Hoy. Soc. 1869, p. 191). 41T4 
grains of the recently fused salt in a platinum boat within a short tube of platinum was 
placed in the middle part of the long platinum tube, and near the exit end of the tube 
was placed a second boat containing 37-88 grains of similar fused fluoride, that end of 
the tube. having a very small exit-tube of platinum. Near the opposite end of the tube 
was placed a third platinum boat containing pure and anhydrous acid fluoride of potas- 
sium, and that end closed by a stopper of platinum. A red heat being now applied to 
the middle boat, and also gentle heat to the third boat very gradually, a current of 
anhydrous hydrofluoric acid vapour passed over the two boats during If hour, the second 
boat being kept below 16° C. When the current of vapour had ceased, the cold boat 
contained a large quantity of liquid anhydrous hydrofluoric acid, which was then expelled 
by application of a gentle heat. The boats were transferred to a closed platinum tube 
and separately reweighed. The residue in the cold boat was of a grey-white colour, and 
in micaceous scales, totally unlike ordinary fmoride of silver; a large portion of the 
fluoride, however, remained unchanged. The weight of this residue was 41 ’48 grains; 
had it all been converted into a salt of the formula AgF, HF the weight would have been 
43-54 grains. ■ The heated boat and its contents had lost only -08 grain; the residue 
consisted of unaltered fluoride, and showed no signs of free silver as it would have. done 
