1871.] 



On a New Group of Colloid Bodies. 



431 



aware that the action of sodium amalgam upon alkali nitrites had been 

 recently investigated by M. Fremy* and M. Maumenef, neither of whom, 

 however, have anticipated me in the discovery of the new class of salts here 

 described. The latter chemist finds that in one set of circumstances this 

 action gives rise to a body allied in composition and properties to oxyam- 

 monia, and in another only to ammonia. M. Fremy finds that it produces 

 oxyammonia, nitrogen which escapes, and nitrous oxide which remains in 

 solution. 



So far as I have since been able to experiment, I have found that, by pro- 

 ceeding in different ways, a very small and variable amount of oxyammonia, 

 or a substance resembling it, is often obtained along with the sodium 

 hyponitrite, which is always formed in material quantity ; and, further, that, 

 under the circumstances which favour the formation of oxyammonia, there 

 are also obtained, together with nitrous oxide, the products of the decom- 

 position of oxyammonia by alkalies — nitrogen and ammonia (Lossen). The 

 presence of oxyammonia in the product of the action of sodium on sodium 

 nitrate affords a more satisfactory explanation than that I have given of the 

 darkening of the silver-salt after precipitation which I have sometimes 

 observed to occur. 



M. Fremy states that alkali nitrites do not decompose potassium per- 

 manganate ; and I now find that my assumption to the contrary is an error, 

 based on an observation of considerable interest, which is that some good 

 commercial nitrite in my possession slowly reduces the permanganate. I 

 have since ascertained that other samples of sodium nitrite have no action 

 on the permanganate, and that the one which does react with it behaves 

 also with copper- and lead-salts in such a way as to render very probable the 

 presence in it of a minute quantity of my new salt. This formation of 

 hyponitrite, by heating sodium nitrate, if it does really take place, is in 

 accordance with Hess's observations of the action of heat on barium nitrate, 

 and with mine on silver nitrite. — E. D. 



III. " Research on a New Group of Colloid Bodies containing 

 Mercury, and certain Members of the series of Fatty Ketones." 

 By J. Emerson Reynolds, Member of the Royal College of 

 Physicians, Edinburgh, Keeper of the Mineral Department, 

 and Analyst to the Royal Dublin Society. Communicated by 

 Robert H. Scott, F.R.S. Received January 19, 1871. 



Introduction. — About ten years ago, when engaged in the examination 

 of some of the constituents of the rectified wood-naphtha of commerce, I 

 observed that moist and freshly precipitated mercuric oxide was dissolved by 

 the naphtha in the presence of potassium hydrate, and that the resulting 

 alkaline solution possessed highly characteristic properties. It was ascer- 



* Comptes Kendus (1870), vol. Ixx. pp. 66 & 1208. 



f Ibid. p. 149. 



