This discovery they communicated to Davy early in June, 

 1808, declaring their conviction that ammonia, like potash 

 and soda, must be an oxide, and that the new substance 

 was a combination of its metallic constituent with mercury. 

 Davy* immediately commenced a series of elaborate experi- 

 ments on the production and properties of the amalgam, 

 and in an account of these experiments laid before the 

 Royal Society in the same month he first uses the name 

 ammonium to indicate the supposed metallic basis of am- 

 monia. So convinced was Davy that the substance united 

 with mercury in the amalgam was of a metallic nature, 

 and that by combining with oxygen it constituted ammonia, 

 that he was inclined to view nitrogen and hydrogen, if not 

 as oxides of metals, at least as metallic gases. 



Davy discovered that the ammonium amalgam was readily 

 produced when an amalgam of potassium was made to act 

 on moistened sal-ammoniac. He found that the electrically 

 prepared amalgam when introduced into a tube rapidly 

 evolved gas, which he describes as consisting of "about 

 two-thirds to three-fourths of ammonia, and the remainder 

 hydrogen." In another experiment, amalgam obtained by 

 potassium was moistened with strong liquid ammonia, and 

 when heated in a tube generated gas which was proved to 

 consist of two-thirds ammonia and one-third hydrogen. 



In the following year Gay Lussac and Thenardf investiga- 

 ted the ammonium amalgam, and were led to regard it as a 

 triple compound of mercury, ammonia, and hydrogen. They 

 found on putting some of the amalgam prepared by potassium 

 into a tube which was filled up with mercury and then 

 inverted in a vessel of that liquid, that the amalgam gave 

 off, in decomposing, ammonia and hydrogen gases in the 

 proportion of 2i volumes to 1. But the electrically pre- 

 pared substance gave off the gases in quite another pro- 



* Phil Trans., 1808, p. 355. 

 t Ueclierclies Pht/sico-Ckimiques, I. 52. 



