ME. GEOEGE GOEE ON FLUOEIDE OF SILYEE. 
325 
water, closed the receiver and shook it ; much heat was evolved : in this experiment 
also air got in and vitiated the measurement. In a third experiment the receiver was 
filled with washed chlorine, 15 grains ( = about 5 grains excess) of the brown fluoride 
put in, then 6 cub. centims. of distilled water added without agitation, the vessel then 
securely closed and immersed in a glass bottle which was quite filled with distilled 
water, and frequently shaken during several hours, and stood all night ; no leakage of 
any kind took place. On opening the lower arm E under a measured amount of distilled 
water, strong rarefaction was found ; the vessel was then closed and again shaken, and 
reopened under water ; about 42 cub. centims. of water ran in altogether, and the volume 
of the gas, after correction for deficient pressure, was 1T89 cub. centims. The gas did 
not cloud a drop of solution of argentic nitrate, and was found to be pure oxygen. 
In this experiment, therefore, 53 cub. centims. or 2-455 grains of chlorine was absorbed, 
and 11-89 cub. centims. or -248 grain of oxygen evolved. The following equation agrees 
substantially with the results obtained : — 
8 Ag F+8C1+ 4H 2 O = 5 Ag Cl + 3Ag Cl Q + SHF + O, 
or 
7Ag C1+ Ag Cl 0 ;5 + 8HF+ O. 
With Hydrochloric Acid. — Two platinum boats, Nos. 1 & 2, containing respectively 
48-25 and 63-33 grains of recently fused fluoride of silver, were placed whilst still warm 
in a horizontal platinum tube, and a slow current of dried hydrochloric acid gas passed 
over them during 2^ hours. No. 1 boat was placed near the exit end of the tube 
and kept cool, and the end of the tube nearly closed by a platinum stopper ; whilst 
No. 2 was enclosed within a short tube of platinum placed in the middle part of the 
longer tube, and heated to incipient redness during the whole of the time. The acid 
gas was dried bypassing through two bottles containing strong sulphuric acid. Vapour 
was evolved, which powerfully corroded glass. The contents of the cold boat soon 
became moist, and also white with superficial formation of argentic chloride ; no sub- 
limate appeared. After the experiment the residue in the cold boat weighed 50-43 
grains, it should have been 54*52 grains if wholly converted into chloride ; and that of 
the heated boat 71*91, theory requiring 71 '55 grains. The residue in the cold boat 
contained soluble silver-salt, whilst that in the heated boat was quite insoluble in water 
The tubes and boats were not visibly corroded, and suffered only minute alterations in 
weight. Thinking that the liberated hydrofluoric acid might possibly by its liquefaction 
have influenced the effects produced in the cold boat, I placed a platinum boat contain- 
ing 34-00 grains of recently fused fluoride of silver, within a similar long platinum tube, 
and passed dried hydrochloric acid gas similarly over it during one hour without appli- 
cation of heat. It then weighed 34*10 grains, and had acquired only a very thin white 
coating of argentic chloride. The residue was freely soluble in water, and the boat was 
unaltered in weight. From these experiments I conclude that fluoride of silver at a 
low red heat is wholly decomposed by anhydrous hydrochloric acid gas and converted 
into argentic chloride, and that in the massive state, as after fusion and cooling, it is 
