te 
340 ? Researches on Salts. . = 
* 2 
SO* (Cut K}H;)= § 800M Oy 
SO:, O, (KH) O. . 
Derived from aifubsulphats SO* (M*) 2 =802,2M270. 
It is only when we treat this salt with water, that we ‘obinish 
bis phiate of potash and insoluble subsulphate of copper. Now 
the brown precipitate formed immediately by neutral chromate of , 
potash in neutral salts of copper, is also a subchromate containing 
both potassium and copper, and boiling water extracts from it bi- - 
chromate of potash, leaving an insoluble subchromate of copper. 
To the action of masses and temperature, then, in double decom- 
position, is united also the influence of a third element, water; an in- 
fluence which is permanent and not so easy to control as the others. 
The water which is present, often enters into the composition 
of salts. Chemists have long since established a difference be- 
tween water of crystallization and that of constitution so called ; 
attempt to demonstrate that basic salts obey in this respect 
> same laws as acid salts. I shall use dualistic formulas to 
‘ the analogy better. 
oxalate of potash. Binoxalate of potash. Quadroxalate of potash. 
2 20 
? 
a 0? 0°, K? 0 O? 0? H* 0 
O:,K?0 Ge O°, H?0 C2 0°, H?0 
C?0°, H:0 
2 he same water of constitution in the salts called basic, 
only the relations of acid, base and water are interchanged. My 
tained, both of them, ina rigs a state. 
unt ve bibasic subnitrate of | lead is 
N? O*, Pb? 0 
ee Pb? 0 * 0, Pree 
H? 0, Pb? 0. 
> - Here the same relations will be peed as between the neu- 
tral oxalate, the binoxalate an iu 
* Ann. de Chimie et de Phys., t. xviii, p. 
