44 IIYPONITEITES ; PROPERTIES AND PREPARATION BY 



method of getting tlie salt. As thus obtained, however, it 

 always has a little chloride mixed with it, and will hardly 

 therefore, be serviceable for any of its purposes. 



The granular form of sodium hyponitrite is best marked 

 in it when it has separated from a highly concentrated solution 

 of sodium hydroxide ; Avhen it is redissolved in a very little 

 water and this is rapidly evaporated in an exhausted desiccator, 

 the salt separates as an almost structureless membrane on the 

 surface and there readily becomes opaque and apparently an- 

 hydrous. In the ordinary desiccator a finely granulated crust 

 forms. I have never got crystals. The salt, quite freshly pre- 

 pared, has an exceedingly mild alkaline taste. 



No very satisfactory results have been got in attempts to 

 determine the degree of hydration of the salt, because of its 

 instability, but they point to the formula, (NaON)o, (OH,v. That 

 formula requires for the sodium the number 23.47 per cent., 

 while analysis of the salt, weighed as soon as it was almost 

 free from alcohol, gave 23.66 per cent. In place of 30.61 per 

 cent, for the hyponitrite ion, 28.10 per cent, was obtained l)y 

 dissolving the salt in Avater and precipitating with silver nitrate, 

 a deficiency fairly attriljutable to decomposition before the sil- 

 ver nitrate could be added ; for, as proved by Zorn, this way 

 of estimating hyponitrous acid is accurate. Loss of weight in 

 the vacuum desiccator gave 44.91 per cent., while the calculated 

 quantity of water is 45.92 per cent., l)ut the difference is easily 

 accounted for as due to loss of nitrous oxide, and, indeed, would 

 be even cjreater but for the fact that this loss involves fixation 

 of water by sodium oxide. 



The anhydrous salt, somewhat decomposed, is non-coherent 

 and opaque, and in appearance much like magnesia alba. It 



