OXYAMIDOSULPHONATE ; DIVERS AND HAGA. 3 



make the whole contents weigh 83.5 grams. (Some lead salt in 

 the nitrite deposits, but goes into solution when the potassium 

 hydroxide is added and gives no trouble). Sodium carbonate 

 of any hydration may here be used but as, later on, more of 

 this salt will be wanted and then should be approximately the 

 monohydrate, it is convenient to use this form throughout. 

 Such a carbonate, almost pure, is generally found in the * dried' 

 pure carbonate of commerce. Keeping the flask in active 

 motion in an ice-and-brine bath, sulphur dioxide is passed in 

 until a short time after the temporarily precipitated acid-carbo- 

 nate has redissolved and when a bit of lacmoid paper in the 

 solution becomes fully red. About j^ cc. strong sulphuric acid 

 is then dropped in. Thus carried out, always below 0°, the 

 conversion of the nitrite into oximidosulphonate is perfect, 

 while much above 3° some nitrilosulphonate would form and 

 disturb everything. If such higher temperatures have been 

 avoided, the nitrite and carbonate taken in close molecular 

 proportions, and the sulphur dioxide not used in excess, the 

 solution is ready to be hydrolysed ; but as the proportions of 

 the salts may have been a little out and also sulphur dioxide 

 be present, it is best to l)low a strong current of air through 

 the solution before its temperature has risen, so as to expel 

 any sulphur dioxide or nitric oxide that may be present. 



After this treatment, the solution is brought to about 30°, 

 iu order to start hydrolysis, then set aside for a day, in a 

 warm place, with the flask corked. Complete hydrolysis to 

 oxyamidosulphonate without further hydrolysis to hydroxyl- 

 amine is thus secured,* and, consequently, just the calculated 



* This success in avoiding production of hydroxylamine has been proved by shaking the 

 soUuion, after it lias been made alkaline, with sudiuiu amalgam which readily converts 



