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XII. On Fluoride of Silver . — Part II. By George Gore, F.R.S. 
Received September 22, 1870, — Read January 12, 1871. 
On account of the prospect of being able to isolate fluorine by means of the action of 
chlorine, bromine, or iodine on argentic fluoride, I have in this investigation very fully 
examined the behaviour of those substances with that compound. 
Behaviour with Chlorine (continued). — To ascertain more completely the nature of the 
compound formed by fluoride of silver with chlorine and platinum at a red heat, I passed 
a very slow current of pure chlorine over 24‘62 grains of argentic fluoride in a platinum 
boat within a 20-inch platinum tube during nine hours at a very low red heat. A very 
minute amount of a vapour which corroded glass was continually evolved ; and traces of 
a sublimate occurred, consisting chiefly of argentic chloride. On heating the boat and 
tube to redness after the experiment, a boiling sound was heard, a little fume and much 
chlorine escaped, and a loss of weight of 1T70 grains took place*. On weighing the 
cooled apparatus a gain of 6‘49 grains upon the original weight still remained, theory 
requiring 6-88 grains if the whole of the fluoride took up its equivalent of chlorine with- 
out any fluorine being expelled. The thick platinum boat was powerfully corroded, 
and immoveably fixed to the tube, even at a red heatf. The residuary salt was easily 
fusible, tasteless, of a dark red colour, and contained much combined platinum ; 3’38 
grains of it fused with alkaline carbonates yielded 2 - 5G grains of metal (theory requiring 
2-51 grains), of which by analysis 1-82 grain was found to be silver, and -74 grain was 
platinum : -63 grain of chlorine was also found in it, showing that the chlorine in it 
was chemically equivalent in amount to the silver. The deficiency of T 9 grain required 
to make up the quantity taken I have set down as fluorine. The red salt corroded glass 
in the presence of damp air, and contained only a few very minute particles of platinum. 
Found. 
Calculated. 
Silver .... 
. 1-82 
1-723 
Chlorine . 
. -63 
•566 
Platinum 
. -74 
•786 
Fluorine . 
. -19 
•303 
Total 
. 3-38 
3-378 
The above calculation is made upon the assumption that the composition of the residue 
is in accordance with the equation 4Ag F+4Cl+Pt = 4Ag Cl, Pt F 4 . The deficiency of 
* Melted chloride of silver absorbs much chlorine gas during the act of cooling ; the resulting compound may 
perhaps be used as a means of getting liquid chlorine. 
t Platinum articles are very liable to adhere together in chlorine at a red heat, occasioning much injury of 
apparatus. 
2 y 2 
