THE GREAT LONDON CHEMISTS 55 



with hydrochloric acid. Davy communicated his dis- 

 covery to Gay-Lussac, who by no means agreed with his 

 conclusions; and it was not until a considerable time 

 had elapsed, and the latter chemist had carried out his 

 masterly researches on iodine and its compounds, that he 

 became convinced of the correctness of Davy's views. 



On his return from this Continental tour, he devoted 

 his time to the investigation of the nature of flame, with 

 the result that he discovered how to prevent flame from 

 spreading into the adjoining atmosphere, by surrounding 

 it with a sheath of wire-gauze ; the conducting power of 

 the gauze so cooling the explosive mixture of gases, that 

 they no longer inflame after traversing the gauze dia- 

 phragm. This invention was hailed with the greatest 

 satisfaction by the public, as well as by those whose 

 interest was bound up in mines; and in 1817, he was pre- 

 sented with a service of plate, valued at 2500, by the 

 owners of many important collieries. His services to 

 humanity were, indeed, valued so highly, that in the 

 following year a baronetcy was bestowed on him. And in 

 1820, on the death of Sir Joseph Banks, who had presided 

 over the meetings of the Royal Society for no less than 

 forty- one years, Sir Humphry Davy received the highest 

 honour which can be bestowed on a scientific man, in 

 being elected his successor. He resigned the presidency 

 in 1827. His own view regarding honours was : ' It is not 

 that honours are worth having, but it is painful not to 

 have them ' ; and again, ' It is better to deserve honours 

 and not to have them, than to have them and not deserve 

 them.' These sentiments remind one of Burns's rhyming 

 grace before meat : 



Some hae meat, and canna eat, 



And some wad eat that want it ; 

 But we hae meat, and we can eat, 



And sae the Lord be thankit. 



