102 Mr. Grove on some Electro-Nitrogtirets. 



From the specific gravity of the cadmium compound I ex- 

 pected it to have yielded more nitrogen, and from the yellow 

 colour of the residue I consider that some of this element, 

 with probably hydrogen, formed a new combination ana- 

 logous to that of ammonia and potassium examined by Sir 

 Humphry Davy; to enter upon this analysis will require a 

 new series of experiments, foreign to the immediate purpose 

 of this paper. Another question of difficult resolution is, 

 whether the hydrogen expelled from the zinc compound was 

 in immediate combination, or resulted from the reaction of 

 the zinc upon combined water: I incline to the opinion that 

 the latter was the case, but see no means of proving it, as the 

 same heat which would expel the water would decompose the 

 substance. Although I had no expectation of procuring a 

 solid compound (the theoretical ammonium), yet I did not 

 neglect the trial; I distilled in the vapour of naphtha some of 

 the zinc compound, but obtained only gaseous products. It 

 may be worth remarking, that the quantities of nitrogen which 

 enter into combination with the metals in these experiments 

 is in proportion to their affinity for oxygen, and it may, per- 

 haps, be considered an argument, in addition to the many 

 already advanced, to prove that nitrogen is an oxide. 



Independently of their individual interest, the strong ana- 

 logy in character, and the manner of formation between these 

 compounds and that of the ammoniacal amalgam, is (to me 

 at least) satisfactory evidence of similarity of constitution. 

 Berzelius supposed this to be an amalgam of mercury and 

 ammonium. Gay-Lussac and Thenard supposed it to be 

 a combination of nitrogen, hydrogen, ammonia and mercury. 

 Mr.Daniell has advanced an opinion, supported by some ex- 

 periments, that it is not a chemical combination, but a mere 

 heterogeneous adhesion, the mercury being puffed up as a 

 soap-bubble. If the above experiments entitle me to ad- 

 vance an opinion without incurring the charge of presumption, 

 I should say that it was certainly a chemical combination, 

 possibly of mercury, nitrogen and hydrogen, but more pro- 

 bably of mercury and nitrogen swelled with hydrogen ; and 

 from the circumstance of its being always moist, contain- 

 ing necessarily a good deal of ammonia, that its non-perma- 

 nence is due sole]}' to the mobility of the mercury; for place 

 this qualuor pedibus with the other metals, i. e. solidify it, 

 and the compound is perfectly permanent ; reduce the other 

 analogous metallic compounds to the state of the mercurial 

 one, i. e. fuse, or even heat them, and they cease to be per- 

 manent. With regard to the hypothesis of ammonium, have 

 we a right to assume the existence of a metal because the 



