264 On Chemical JVomendature. 



neutral, it has almost the same acidity of taste as the hydrofluoric acid 

 employed. The new base does not destroy then the acid reaction. 



Let us make a further addition of sulphuric acid to the sulphate 

 of potash. A salt equally acid will resuU, in which the sulphate of 

 of potash acts the same basic part towards the sulphuric acid, as the 

 fluoride of potassium towards the hydrofluoric acid. Should it be 

 desired to extend the comparison further, it will be found that for 

 each less electro-positive fluoride, susceptible of combination with the 

 potassic fluoride, there will be, with but very few exceptions, a cor- 

 responding sulphate, susceptible of combination with the sulphate of 

 potash. The analogy is then complete, it exists not only in the per- 

 fect neutrality of the two potassic salts, in their saline taste, but also 

 in their manner of forming combinations with other bodies ; notwith- 

 standing one of them, the sulphate, contains one element more than 

 the other. If, instead of potash, potassium were employed to sat- 

 urate our two acids, the analogy of the operation in both cases, 

 would be still more complete. The same quantity of metal would 

 displace equal volumes of hydrogen. When the visible results of 

 our experiments are so perfectly analogous, it is to be presumed that 

 the invisible process which we do not see, may also be perfectly 

 analogous, and that if facts exactly alike are explained differently, 

 there must be a defect in the explanation. If, for instance, the true 

 electro-chemical composition of the sulphate of potash should not be 

 KO-fSO^, as is generally supposed, but K+SO^* and it appears 

 very natural that atoms, so eminently electro-negative as sulphur and 

 oxygen, should be associated, we have, in the salt in,question, potas- 

 sium combined with a compound body, which, like cyanogen in 

 K-f-C^ N,f imitates simple halogen bodies, and gives a salt with 

 potassium and other metals. The hydrated oxacids, agreeably to 

 this view, would be then hydracids of a compound halogen body, 

 from which metals may displace hydrogen, as in the hydracids of 

 simple halogen bodies. Thus we know that SO^, that is to say, 

 anhydrous sulphuric acid, is a body whose properties, as respects 

 acidity, differ from those which we should expect in the active prin- 

 ciple of hydrous sulphuric acid. 



* In the Berzelian symbols, K stands for kalium, or potassium, S for sulphur, 

 O for oxygen, and 3 for three atoms of oxygen, 04 for four atoms of oxygen. 



t That is to say, if the salt called sulphate of potash, be considered as compound 

 of potassium, and a quadroxide of sulphur, instead of being viewed as a protoxide 

 of potassium, or potash, and tritoxide of sulphur, or sulphuric acid. This is the 

 formula for cyanide of potassium, consisting of potassium, K, and cyanogen, or 

 two atoms carbon and one of nitrogen, Cs N. 



