ACTION OF POTASSIUM ON AMMONIA. <243 



Iii a paper read before the Royal Society last June, which 

 they have done me the honour of printing, I have given an 

 account of various experiments on the amalgam from am- 

 monia, discovered by Messrs. Berzelius and Pontin, and in Opinions of 

 a note attached to this communication, I ventured to con- ^The^rd 

 trovert an opinion of M. M. Gay Lussac and Thenard with erroneous. 

 respect to the agency of potassium and ammonia, even on 

 their own statement of facts, as detailed in the Moniteur for 

 May 27, 1808. 



The general obscurity belonging to these refined objects 

 of research, their importance and connection with the whole 

 of chemical theory, have induced me since that time to ap-» 

 ply to them no inconsiderable degree of labour and atten- 

 tion ; and the results of my inquiries will, 1 trust, be found 

 not only to confirm ray former conclusions; but likewise to 

 offer some novel views. 



In the first of these series of operations on the action of Apparatus, 

 potassium on ammonia, I used retorts of green glass; I 

 then, suspecting oxigen might be derived from the metallic 

 oxides in the green glass, emploj r ed retorts of plate glass, 

 and last of all, I fastened the potassium upon trays of pla- 

 tina, or iron, which were introduced into trie glass retorts 

 furnished with stop cocks. These retorts were exhausted by 

 an excellent air pump, they were filled with hidrogen, ex- 

 hausted a second time, and then filled with ammonia from 

 an appropriate mercurial gas holder*. In this way the gas 

 was operated upon in a high degree of purity, which vyas al- 

 ways ascertained ; and all the operations performed out of 

 the contact of mercury, water, or any substances that could 

 interfere with the results. 



I at first employed potassium procured by electricity ; but Potassium 

 I soon substituted for it the metal obtained by the action of used * 



* A representation of the instruments and apparatus is annexed. 



PI. Vll. fig. 1. The retort of plate glass for heating potassium in 

 gasses. 



Fig. 2. The tray of platina fur receiving the potassium. 



Fig. 3. The platina tube for receiving the tray in experiments of dis- 

 tillation. 



Fig. 4. The apparatus for taking the voltaic spark in sulphur and 

 phosphorus, 



R 2 



