1904-5.] Mr Cameron on the Constitution of Complex Salts. 735 
With bivalent metals type A. 1 is represented by such salts as 
the series M 2 'M"(S0 4 ) 2 , 6H 2 0 , and Hg : [(SClSr) 2 .M] 2 , and type 
A. 2 by K 2 Mn 2 (Cr0 4 ) 3 , 4H 2 0 , and K 2 Zn 2 F 6 . Every normal or 
as belonging to the type A. 1 ; “ Double salts” as K.(CN) 2 .Ag and 
K.(F 2 ).H afford examples of the corresponding derivatives with 
monobasic acids. 
I have already mentioned reasons for disbelief in the existence 
of definite chromoxalates such as K 5 NH 4 Cr 2 (C 2 0 4 ) 6 . 
Among compounds to which constitutions in accordance with 
the types cannot be given, are the aluminium oxalates prepared by 
Rosenheim and L. Cohn * having the constitution 
To explain the existence of these compounds the authors assume 
that in concentrated alkaline solution aluminium hydroxide can 
exist as Al 2 (OH) 6 . Rosenheim and Bierbrauer f have prepared 
various antimonyl oxalates, which they consider to be double salts 
of the complex antimonyl oxalates with ammonium or potassium 
hydrogen oxalate. To some of these, however, formulae in 
accordance with the types can be assigned. Thus the compound 
2(NH 4 ) 2 0, Sb 2 0 3 , 6C 2 0 3 , 6H 2 0 may be written 
Finally, the amorphous “ sulphochromosulphates ” of Recoura | 
may be mentioned. These cannot be derived from the simple 
molecule Cr(OH) 3 . 
acid salt of a dibasic acid with a univalent metal must be considered 
Compounds whose formulae, cannot be derived from the system of 
types enumerated. 
OH 
,c 2 o 4 -nh 4 
* Zeit. filr anorg. Chew,.. 11, p. 184. 
X Bull. Soc. Chem. , iii. , 17, p. 934. 
f Ibid., 20, p. 303. 
