1809. JET. 31.] PROFESSOR DAVY. 359 



action of potassium on ammonia. Nitrogen was lost. 

 If the nitrogen is to be considered as converted into 

 oxygen and hydrogen, it must be regarded as containing 

 much more oxygen than water ; and if we do not adopt 

 this supposition, the only alternative is that water is 

 the ponderable matter which, under different modifica- 

 tions of electro-chemical existence, constitutes oxygen, 

 hydrogen, nitrogen, and the nitrous compounds.' 



On February 15 he wrote in the Laboratory Book, 

 ' Were a description, indeed, to be given of all the 

 experiments I have made, of all the difficulties I have 

 encountered, of the doubts that have occurred, and the 

 hypotheses formed ' The sentence was not finished, 

 and more time was lost on the investigation. 



Throughout the spring and summer more experiments 

 were made on ammonia and nitrogen. 



He ignited potassium by the voltaic spark in nitrogen, 

 and found that some hydrogen was evolved and some 

 nitrogen lost ; but when the potassium was free from 

 potash this did not occur, and at last he gave up trying 

 to show that nitrogen was a compound of oxygen and a 

 metallic basis. 



At the end of August he was working on tellurium 

 and made telluretted hydrogen. 



To his mother he wrote in August : 



At present, except when I resolve to be idle for health's 

 sake, I devote every moment to labours which I hope will 

 not be wholly ineffectual in benefiting society, and which 

 will not be wholly inglorious for my country hereafter ; and 

 the feeling of this is the reward which will continue to keep 

 me employed. 



