458 DAVY. 



fest he intended still to persevere till he should make 

 other discoveries. Any one possessed of a strong bat- 

 tery, deeply reflecting on the paper of autumn 1806, 

 and perceiving that the positive wire had such a 

 strong attraction for oxygen as to take it from metallic 

 oxides, reducing them to their reguline state, might 

 well have bethought him of subjecting the alkalis to 

 his machine ; and he would then have had the fame, 

 though, in truth, Davy would have had the merit, of 

 the grand discovery. 



That discovery was not long delayed. About a year 

 after the former, that is in October 1807, after in vain 

 endeavouring to decompose the alkalis when mixed 

 with water, for he then only could decompose that 

 fluid, he exposed them in the dry state ; that is, made 

 liquid by fusion, without any other substance but heat 

 to dissolve them and, to his great delight, he found, 

 as he had a right to expect, that the process of deoxi- 

 dation proceeded by the positive wire attracting the 

 oxygen, while globules of a metallic substance were 

 found at the negative wire. The great attraction of this 

 metal for oxygen made it impossible to keep it either 

 in the air or in water. It burnt spontaneously in the 

 air and became alkali it decomposed water in like 

 manner, and formed an alkaline solution. The two 

 fixed alkalis both yielded in this process metallic bases ; 

 but that of potash had alone the quality of combustion 

 at the temperature of 150, and it was, though a metal, 

 lighter than water in the proportion of 97 to 100. 

 When thrown into water in the air, it detonates and 

 burns with violence, forming a solution of potash. 

 The metal from soda is still lighter, being to water as 

 86 to 100 ; but it does not so easily unite with oxygen, 



