SODIUM OE POTASSIUM : EDWAED DIVEES. 03 



decomposition in 24 honrs. At a lower temperature, Thura 

 observed a loss only half as great in the same time. Hyponi- 

 trons acid solution dissolves silver hyponitrite slightly. The 

 alkali salts of hyponitrons acid dissolve silver hyponitrite some- 

 what more freely, and also decompose silver chloride (see pp. 

 45, 52) ; they also give precipitates with barium and calcium salts 

 and with solutions of most metallic salts. Alkali hyponitrites 

 in solution also decompose into nitrous oxide and alkali, gradu- 

 ally in the cold and rapidly when heated ; alkali hydroxides 

 impede the decomposition and when highly concentrated stop 

 it apparently altogether (see p. 38) ; neutralisation of the alkali, 

 even by carbonic acid, hastens the decomposition as a matter 

 of course, l)ut there is no evidence that carbonic acid is able 

 to decompose a hyponitrite, as it has been stated to be. 



Other substances are liable to be present in the solution 

 of hyponitrons acid, and this fact has caused the properties of 

 the acid to be certainly in some points wrongly described. 

 In one point it was so by me in my first paper, in which, 

 however, was contained the warning that the crude solution of 

 the acid, which had been examined, might have reacted as it 

 did, partly through the presence of other unrecognised sub- 

 stances in it. That solution decolourised iodine water and 

 prevented the action of nitrous acid on an iodide ; but tliis was 

 not by the hyponitrons acid in it but by a very little hydroxyl- 

 amine then unrecognised. Kirschner has again given to hypo- 

 nitrous acid the property of decolourising iodine water to a 

 slight extent- In his case the substance active upon the iodine 

 will have been a trace of sulphur dioxide ; for he made his 

 solution of the acid from silver hyponitrite that had been 

 prepared by the oxyamidosulphonate method. I can confirm 



