292 



E. DIVERS AXL) T. HA.GA ; 



with marked rise of temperature, into oxyamidosulphonate and acid 

 sulphate. The solution of these salts is kept at 90-95° for two days, by 

 the end of which time, all oxyamidosulphonate will have hydrolysed 

 into hydroxylamine sulphate and sodium acid sulphate, while so small 

 a quantity of ammonium salt is produced, as can only be detected in 

 the very last mother-liquors of crystallisation by chloroplatinic acid 

 (potassium hydroxide being an unsuitable reagent in presence of 

 hydroxylamine). At 80-85°, five days are necessary, but then 

 practically no ammonia is formed ; at 70°, three weeks, at least, are 

 necessary; while, at the common temperature, much oxyamidosulphonic 

 acid remains after several months, even Avhen much sulphuric acid has 

 been added. On the other hand, the solution kept boiling needs 

 seven or eight hours usually to deprive it of all sulphonate ; but the 

 boiling has disastrous effects on the hydroxylamine, destroying at 

 east one-third of it, by converting it (through amidosulphonic acid ?) 

 into ammonia, and wasting another third as a practically inseparable 

 mixture of its sulphate with ammonium sulphate. 



To be assured of the disappearance of all sulphonate, it is well to 

 add barium chloride in excess to a little of the solution and filter, and 

 then boil the filtrate with potassium chlorate, which will change any 

 sulphonate into sulphate, bulphonation complete, the solution is 

 neutralised with sodium carbonate using methyl orange as indicator, 

 and evaporated till it weighs only 10J to 11 times as much as the 

 sodium nitrite taken. Left to cool where its temperature will fall to 

 0° or lower, nearly all its sodium sulphate will crystallise out. The 

 mother-liquor evaporated sufficiently and cooled to the common 

 temperature yields much hydroxylamine sulphate, the mother-liquor 

 from which, very slightly diluted and cooled below 0°, gives again a 

 little sodium sulphate, and can be worked for more hydroxylamine 

 sulphate, as before. 



