OXYAMIDOSULPHONATE ; DIVERS AND HAGA. Ö 



dissolve in water without much rise of temperature. From 130 

 to 165 grams of it, according to its degree of hydration, are 

 quickly crushed in a warm mortar and thrown into the solution 

 in the basin and incorporated with it by means of a pestle. 

 There is marked heating only just at first, which is better met 

 by keeping the basin in water or resting on snow or pounded 

 ice for a very short time. On stirring-in the potassium 

 hydroxide the solution sets to a stiff paste, if kept cold, quickly 

 becoming thin again by further stirring, but full of opaque 

 white precipitate of sulphate. If the basin has been cooled, 

 hardly any gas escapes at first, but gentle effervescence and 

 much frothing occur before long in any case. When the potas- 

 sium hydroxide has been all ground up and dissolved, the 

 basin is placed under close cover from atmospheric moisture 

 and carbonic acid, and left so for 30 hours in a warm place 

 (Kept for more than 50 hours, the quantity of hyponitrite 

 sensibly but slowly diminishes). As much even as one-fourth 

 of the oxyamidosulphonate may sometimes in cold weather still 

 be present and can be partly destroyed by keeping the basin 

 at 55-60° for half an hour, though not with noticeable increase 

 of the quantity of preserved hyponitrite. This heating, with 

 the risk attendant on it of destructive over-heating, is better 

 omitted, on the whole. Besides undecomposed oxyamidosulph- 

 onate, the contents of the basin now consist of precipitated 

 sulphate and sulphite, and solution of potassium hydroxide in 

 slightly less than its weight of water (almost exactly, K0H:3Hp), 

 together with the potassium hyponitrite. It is, apparently, only 

 to secure this concentration of the potassium hydroxide, a prac- 

 tically saturated solution, that hardly less than 10 mois, of it 

 to one oxyamidosulphonate have to be used. More of it may 



