46 ESSAYS BIOGRAPHICAL AND CHEMICAL 



and ammonia. By 1801 he had begun his experiments 

 with the ' galvanic battery,' which was to be so fruitful of 

 important results in his hands. During these two years, 

 he published no fewer than nine papers in the scientific 

 journal of his time, Nicholsons Journal, the predecessor 

 of the Philosophical Magazine, the result of astonishing 

 industry. 



At this period of his life, Davy's acumen led him to 

 avoid undue theorising, and to endeavour to accumulate 

 facts. His own words are : ' When I consider the variety 

 of theories that may be formed on the slender foundation 

 of one or two facts, I am convinced that it is the business 

 of the true philosopher to avoid them altogether. It is ' 

 more laborious to accumulate facts than to reason con- 

 cerning them ; but one good experiment is of more value 

 than the ingenuity of a brain like Newton's.' In the light 

 of this opinion, it is interesting to examine the programme 

 which he laid down for himself at the time. It was 

 written in the spring of 1799, and is as follows : 



* To decompose the muriatic, boracic, and fluoric acids ; 

 to try triple affinities, and the contact with heated com- 

 bustible bodies at a high temperature. 



' To ascertain all the phenomena of oxydation. 



' To discover with accuracy the vegetable process.' 



The decomposition of the muriatic and the boracic 

 acids was successfully accomplished at a much later date. 

 But the ' phenomena of oxydation ' are even now known 

 only imperfectly. He contributed useful facts, however, 

 as we shall see, to our knowledge of ' the vegetable 

 process.' 



Consistently with these ideas regarding the relative 

 merits of theory and practice, Davy made his greatest 

 successes in the realm of facts. Where he attempts 

 theorising, the results are not happy. It is true that he 

 did not risk the publication of his theories ; but those 



