4 AET. 14. T. SUZUKI : THE OXIMES AND 



ensure the complete precipitation of zinc carbonate. Tiie solution 

 is filtered, and the filtrate, together with the washings, is evapo- 

 rated on a water-bath, in order to reduce the volume. After 

 cooling it down to the ordinary temperature, or better to below 

 10°, 6 grammes of sodium nitrite are dissolved in it, and then 

 dilute sulphuric acid is added in small quantities with constant 

 stirring, the solution being kept continually cooled so as to avoid 

 the rise of temperature. At first the solution acquires a red 

 tint,^ which, however, fades away on the continued addition of 

 the acid, and then a white crystalline precipitate of m-benzene- 

 disulphoxime begins to appear. After adding an excess of dilute 

 sulphuric acid the precipitated oxime is set aside for some time, 

 which is then collected upon a filter, washed with water, and 

 dried in a desiccator over sulphuric acid. When the operation 

 is well conducted the dried mass amounts to over lo grammes, 

 or about dO^/o of the theoretical yield. The crude oxime is re- 

 crystallised from hot acetone, which is the best solvent for it. 

 The solubility of the oxime in boiling acetone is about 5 parts in 

 100 ; but the solution can attain a considerable degree of super- 

 saturation and furnishes well formed crystals on evaporation 

 or cooling. The decomposition point of the pure crystals is 

 exactly 216^ 



Analytical data. 



a) 0.2237 gr. of the crystals from the alcohohc solution, on drying 

 at 100°, lost 0.0286 gr. 



Found Cal. fur <C„H, (SO,), NOH}, • U C,H„ O 



Alcohol 12.78^ 12.79^^ 



1. The coloratiun seems to be due to some impurity, because on repeating the same 

 reaction rritli a salt of pure m-benzenedisulphinic acid no coloration was observed. 



