PEROXYLÀMINE8ULPH0N LTES AND HYDBOXYLAMINETEISULPHONATES. '.) 



peroxide. It is more difficult to purify from accompanying salts than 

 the potassium salt, but by very cautious addition of sulphuric acid, 

 these suits may be converted into sulphate, which can be easily separated 

 from the hydroxylaminetrisulphonate by freezing. It crystallises in 

 aggregates of small, tabular, monoclinic crystals (p. 31). The solubility 

 of the salt is considerable, one part requiring only 2.83-2.85 part-, 

 of water at 21.5°. Like the potassium salt, it is neutral to indicators, 

 and, when heated, hydrolyses in its water of crystallisation. 



Ammonium Hydroxylaminetrisulphonate, H^Oa^S,. or 

 2(S0 3 NH 4 )ON(S0 3 NH 4 ) 2 ,3H 2 0. 

 The analysis of this salt confirms the view that the amount 

 of water present in the potassium salt is greater than that found 

 by Clans. The ammonium salt forms thick, rhombic plates and prisms, 

 similar to those of the potassium salt and probably isomorphous with 

 them. But goniometric examination was impracticable, for although 

 some faces were 7-9 mm. long, others were too imperfectly developed 

 for determination. The salt is neutral to litmus and methyl-orange, 

 and generally like the potassium salt, but it is exceedingly soluble in 

 water, one part dissolving in 0.G1 part at 16°. The salt examined was 

 prepared by digesting the basic lead salt with ammonium carbonate 

 and evaporating the solution on the water-bath until it had almost lost 

 it-, alkalinity, and then concentrating it further under reduced pressure 

 over solid potassium hydroxide. Its nitrogen and sulphur were found 

 to be in much closer agreement with the formula showing 3/2 molecules 

 of water : but here a «rain the difference between the numbers for the 

 two formulae is not very great (p. 32). 



Hydroxy-leadHydroxylaminetrisulphonate^ 1 [ 9 19 $ S 3 Pb 6 or 

 ON(S0 3 PbO-PbOH) 3 ,3H 2 0. 

 This tetrabasic and very insoluble lead salt, which appears tobe the 

 only insoluble hydroxylaminetrisulphonate, was prepared by pouring 



