54 Remarks on the Theory of Compound Salt Radicals. 



very much too broad, even were it asserted of the oxyacids alone. 

 These, as already observed, constitute, even upon the ordinary 

 view, about one fourth of the whole number of those usually ad- 

 mitted by chemists. Whereas agreeably to the views of Bons- 

 dorff, Hare and Thomson, in accordance with which, what are 

 termed double chlorides, double iodides. &c. are really simple 

 salts of halogen acids and bases, the oxysalts do not constitute 

 the eighth part of the whole number of salts at present known 

 and described. While if those saline substances, the electro- 

 negative ingredients of whose acids and bases are compound rad- 

 icals like cyanogen, amidogen,or mellon, are taken into the com- 

 putation, the number of the oxysalts becomes comparatively 

 very small. 



7. In the next place, while it is asserted that the hypothetical 

 salt-radicals by combining with electro-positive substances form 

 compounds exactly analogous in constitution to simple chlorides, 

 iodides, &c, it has not been observed that if they indeed do so, 

 they become precisely as similar to oxides and sulphides as to 

 chlorides and halides generally. Since, till the new theory of 

 salts began to occupy a prominent place in theoretical chemistry, 

 the existence of a halide of any particular atoriiic constitution or 

 type was deemed a priori almost a demonstration of the exist- 

 ence of amphides of the same type, and vice versa. So that if a 

 protochloride and a sesquichloride of a new metallic radical were 

 to be discovered, it might thence be immediately and certainly in- 

 ferred that there were oxides, sulphides, selenides and teliurides, 

 as well as iodides, bromides and fluorides of an exactly analo- 

 gous composition. If therefore the formulas, M-fS0 4 , M+2S0 4 , 

 M 2 +S0 4 , M 2 +3S0 4 , adduced by Prof. Graham, from their 

 obvious analogy to those of simple chlorides, M + Cl, M+2CI, 

 M 2 +C1, M 2 +3C1, be considered as demonstrating the general 

 molecular resemblance of the salts containing compound salt- 

 radicals to the simple halides, they must also demonstrate their 

 analogy to the oxides and sulphides whose formulas are precise- 

 ly similar, M + O, M+20, M 2 +0, M 2 +30, M+S, M+2S, 

 M 2 + S, M 2 +3S. 



8. The analogy between the compound electro-negative ions 

 assumed in the new theory, to the simple halogen bodies, will be 

 found upon close examination to be extremely superficial. If for 

 instance the monobasic, bibasic and tribasic oxyphosphions P0 6 , 

 P0 7 , P0 8 , are analogous to chlorine, why should they be inca- 



