Lenlier—Fluoride of Gold. 
315 
It is obvious that fluoride of gold cannot be prepared by the ac¬ 
tion of hydrofluoric acid on the oxide. The next most natural 
method to try for the preparation of the fluoride would be that 
of double decomposition. 
Silver fluoride and gold chloride, both being soluble salts, on 
being brought in contact in solution should yield theoretically: 
Au Oh + 3 Ag F = Au F 3 + 3 Ag CL 
The actual case is that when solutions of these two salts are 
brought in contact, hydrate of gold is quantitatively thrown out 
of solution along with silver chloride, thus: 
Au Cl 3 + 3 Ag F + 3 H 2 0 = 3 Ag Cl + Au (OH) s + 3 TIE. 
The accuracy of this reaction has been carefully established in 
the laboratory. 
If gold fluoride is even momentarily formed it is immedi¬ 
ately decomposed by water. 
The method yet remaining for the preparation of a substance 
incapable of existence in presence of water would be the use of 
anhydrous solvents. A large number of organic solvents have 
been tried with this end in view but no substance has been found 
which would dissolve both gold chloride and silver fluor¬ 
ide; either these salts are insoluble or are: decomposed by the 
substances worked with. Among the solvents examined, men¬ 
tion may be made of the following: alcohol, ether, carbon bi¬ 
sulphide, benzene', turpentine 1 , pentane, hexane, chloroform, car¬ 
bon tetrachloride, ethyl nitrate, nitrobenzene, ethyl acetate, 
ethyl propionate, and pyridine. 
It thus appears that fluoride of gold is incapable of existence 
not only in presence of water but under the ordinary conditions 
met with in the laboratory and in nature. 
