SODIUM OR P0TASSIU3I : EDWARD DIVERS. /O 



by sodium hydroxide and is soluble in dilute acids and ammonia. 

 Thum lias shown its composition to be Cu(OHjNO. It gives 

 ■water, cupric and cuprous oxides, and nitrous and nitric oxides 

 when heated. By adding copper sulphate in excess to hydroxyl- 

 amine sulphate and then a very little ammonia, it can also be 

 precipitated in small quantity. 



Cuprous liyiwnitrile cannot be formed. I have tried to get 

 it by precipitating sodium hyponitrite by copper sulphate in 

 presence of free hydroxylamine, but first cuprous oxide precipi- 

 tated and then by aerial oxidation the basic cupric hyponitrite, 

 which in composition is equivalent to that of cuprous hyponitrite 

 combined with hydroxyl (see above). 



Lead hyponitriie. — This salt was also briefly described by 

 me and has been prepared and analysed by Thum. Kirschner 

 has again prepared it and analysed it, but not in a pure state. 

 It precipitates cream yellow and flocculent, but soon becomes 

 very dense and sulphur yellow. Its first state is probably that 

 of a hydrate ; Kirschner has mistaken it for a basic salt. The 

 yellow salt is PbXXL. As Thum has pointed out the yellow 

 precipitate when formed in a weak acid solution, is crystalline 

 and just like ammonium phosphomolybdate. It is soluble in 

 dilute nitric acid and is decomposed by sodium hydroxide but 

 not by sodium carbonate in the cold. 



Ammonium hydrogen hyponitrite. — This salt has been de- 

 scribed by Hantzsch and Kaufmann who found it to be exceed- 

 ingly unstable, as was to be expected. That the normal salt 

 could not exist had already been pointed out by me and by 

 Zorn. D. H. Jackson believes, however, that he did obtain it 

 in small quantity in prismatic crystals, but it is exceedingly 

 improbable that he did. 



