ACTION OF POTASSIUM ON AMMONIA. > 251 



same as hidrogen and nitrogen, nearly in the proportions in 

 which they exist in volatile alkali, are evolved during the 

 exposure of the compound to the degree of heat which I 

 have specified; and as the residual substance produces am- 

 monia with a little hidrogen by the action of water, it oc- 

 curred to me, that, on the principles of the antiphlogistic 

 theory, it ought to be a compound of potassium, a little 

 oxigen and nitrogen, or. a combination of a suboxide of 

 potassium and,nitrogen; for the hidrogen disengaged in the 

 operations of which it was the result nearly equalled the 

 whole quantity contained in the ammonia employed; and 

 it was easy to explain the fact of the reproduction of the 

 ammonia by water, on the supposition, that by combination 

 with one portion of the oxigen of the water, the oxide of 

 potassium became potash, an,d by combination with another 

 portion and its hidrogen, the nitrogen was converted into 

 volatile alkali. 



With a view to ascertain this point, I made several expe- Experiment* 

 riments on various residuums, procured in the way that I to pro^e this, 

 have just stated, from the action of equal quantities of pot- 

 assium on dry ammonia in platina trays, each portion of 

 metal equalling six grains. 



In the first trials, I endeavoured to ascertain the quantity Quantity of 

 of ammonia generated by the action of water upon a resi- ammonia pro* 

 duum, by heating it with muriate of lime or potash par- 

 tially deprived of moisture; and after several trials, many 

 of which failed, I succeeded in obtaining four cubical in- 

 ches and a half of ammonia. In three other cases, where 

 there was reason to suspect a small excess of water, the 

 quantities of ammonia were three cubical inches and a half, 

 three and eight tenths, and four and two tenths. 



These experiments were performed in the iron tube used 

 for the former process ; the tray was not withdrawn ; but the 

 salt introduced in powder, and the apparatus exhausted as 

 before, then filled with hidrogen, and then gently heated in 

 a small portable forge. 



Having ascertained what quantity of ammonia was given The com- 



off from the residuum, I endeavoured to discover what P°« rif * intro- 



p '2. j i • i n duced into ox- 



quantity ot nitrogen it produced in combustion, and what jgen « T as. 



quantity of oxigen it absorbed. The methods that I em- 

 ployed, 



