[ 146 ] 



XXV. The Bakerian Lecture, on some new Phcenomena of 

 Chemical Changes produced by Electricity, particularly 

 the Decomposition of the fixed Alkalis, and the Exhibition 

 of the new Substances which constitute their Bases; and 

 on the general Nature of alkaline Bodies. By Humphry 

 Daw, Esq., Sec. R. S. M.R.LA. 



[Concluded from p. 112.] 



VIII. On the Nature of Ammonia and alkaline Bodies in 

 general: with Observations on some Prospects of Discovery 

 offered by the preceding Facts. 



xjlmmonia is a substance, the chemical composition of 

 which has always been considered of late years as most per- 

 fectly ascertained, and the apparent conversion of it into 

 hydrogen and nitrogen, in the experiments of Scheele, 

 Priestley, and the more refined and accurate experiments of 

 Berthollet, had left no doubt of its nature in the minds of 

 the most enlightened chemists. 



All new facts must be accompanied however by a train of 

 analogies, and often by suspicions with regard to the accu- 

 racy of former conclusions. As the two fixed alkalis con- 

 tain a small quantity of oxygen united to peculiar bases, 

 may not the volatile alkali likewise contain it ? was a query 

 which soon occurred to me in the course of inquiry ; and in 

 perusing the accounts of the various experiments made on 

 the subject, some of which I had carefully repeated, I saw 

 no reason to consider the circumstance as impossible. For 

 supposing hydrogen and nitrogen to exist in combination 

 with oxygen in low proportion, this last principle might 

 easily disappear in the analytical experiments of decomposi- 

 tion by heat and electricity, in water deposited upon the 

 vessels employed or dissolved in the gases produced. 



Of the existence of oxygen in volatile alkali I soon satis- 

 fied myself. When charcoal carefully burnt and freed from 

 moisture wa$ ignited by the Voltaic battery of the power of 

 250 of six and four inches square, in a small quantity of 



very 



