OXIMIDOSüLPHOXATES OR SüLPHAZOTa.TES. 35 



The le.'is alkaline salts, called in the case of potassium, basic .ml- 

 phazotate by Fremy and sulphazotate by Claus and by Raschig, are 

 double salts of the normal and the acid or hydrogen salts, thus : — 



HOXC^OsK),, KONCSOsK)^ and H0N(.S03Na)„ :i NaON(S03Na)-,, 



pentapotassiiiiii hi-oximidosidphonate and octasodiuui fer-oximidosulphonate. 



ISTothing is wanting in the evidence to the truth of the views here 

 set down. Any acid serves to replace in the normal salts the third 

 atom of metal by hydrogen ; many salts, such as zinc sulphate, do the 

 same (p. 3o) ; potassium or sodium hydroxide directly reacts with 

 the hydrogen salts to replace some or all of the hydrogen by metal, 

 and just as readily as it does with phosphoric acid, which, as is well 

 known, does not excliange all its hydrogen for metal unless the alkali 

 is used in good excess. 



That the pentapotassium and octasodiuui comj)ounds are double 

 salts is a conclusion in accordance with all that is known of them. 

 They are formed by the simple union of the hydrogen salt A\ith 

 the normal salt in solution, even when the quantities of these 

 salts deviate to a not inconsiderable extent ïvoin their proportions 

 in the compound salts, and they have an action on litmus, Phenol- 

 phthalein, etc., the same as that of the normal salts alone. In reac- 

 tion they decompose into their component salts, one only being active. 

 Fremy observed that lead and barium salts added to a solution of the 

 pentapotassium salt gave precipitates more basic than it and left in 

 solution the neutral potassium salt ; but as he did not know of the 

 existence of the normal potassium salt, and got complex basic pre- 

 cipitates, he could not represent the change quite as we do. E\en 

 now it still remains open to say with him that a basic salt precipitat- 

 ing, the acid of the precipitant converts anc^ther portion nï the 

 alkaline potassium salt into the neutral one, though tu do so is to 



