Halogens, elemental antimony halides

CsCl HgCl2=3 1, 2 1, 1 1, 2 3, 1 2, and 1 5 and five caesium antimonious fluorides where CsF SbF3=l 1, 3 4, 4 7, 1 2, and 1 3. According to I. Remsen s rale (1889) When a halide of any element combines with a halide of an alkali metal to form a double salt, the number of molecules of the alkali salt which are added to one molecule of the other halide is never greater, and is generally less than the number of halogen atoms contained in the latter—for instance, in the double fluoride of sodium and aluminium, where the negative halide has three fluorine atoms, no more than three molecules of sodium fluoride will be found united with one of aluminium fluoride. 

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