oß HYPONITKITES ; PROPERTIES AND PREPARATION BY 



Using such proportions of water, the sodium oxide produced 

 finds about enough to form with itself a sohition of the com- 

 position, NaOH,30lL, which, according to my measurements, 

 is a nearly saturated solution of NaOH,OH_,, at the mean tem- 

 perature.* In presence of so much hydroxide the water is 

 also fjuite saturated with hypouitrite, a small quantity of this 

 salt even separating when the solution is kept ice-cold for a time. 

 To reduce sodium nitrite in cold concentrated solution, 2^ 

 atoms of sodium are found to be needed, the additional half 

 atom being consumed in the unavoidable formation of some 

 nitrogen, hydroxjdamine, and ammonia. This accords well 

 enough with the statement in my first paper as a first approxi- 

 mation, that not more than 4 atoms are active upon sodium 

 nitrate. In practice, however, 3 atoms of sodium (nitrite and 

 metal, equal weights, therefore) should be used in reducing 

 sodium nitrite, partly because it is wanted afterwards to reduce 

 hydroxylamine, and partly because the reduction of all the 

 nitrite is important, and this can only be accomplished quickly 

 in presence of good excess of sodium. The strength of the 

 amalgam is not an essential point, as regards the nature of its 

 action ; some chemists state the contrary, but as the amalgam 

 and the aqueous solution constitute together a heterogeneous 

 system, I do not see how they can be right. But I have always 

 found it most convenient to prepare and to work with a soft 

 solid amalgam, which is one having the composition, (NaEgs),., 

 or 2-J grams sodium to IGOO grams mercury.'"-' 



■■•■ Sodium liydroxide forms a saturated solution at 15° in its own weight of water. ^Vlicn 

 cooled, this solution deposits large pointed prisms of the luonoliydrate. 



'■■"•■■ Ta nalar en-cd in sujiposing that I reconnnended tlie use of linrd amalgam, and liis 

 su])posed improvement of my process, like those publislied hy otlier cliemists, is not one in fact. 



