DAVY. 461 



the old and received opinion. Davy now found, by a 

 course of satisfactory experiments which have fixed the 

 opinions of all philosophers on the subject, that the 

 suspicion of those eminent men was well founded ; that 

 the oxymuriatic acid is a simple substance, containing 

 no oxygen; that it unites with oxygen to form an 

 acid, which forms with alkalis the detonating salts 

 hitherto called oxymuriates, as being supposed to 

 contain oxymuriatic acid combined with alkaline bases ; 

 and finally, that with hydrogen it forms the acid long 

 and well known as the muriatic or marine. To the 

 oxymuriatic acid he gave the name of chlorine from 

 its green colour, and to common muriatic acid that of 

 hydrochlorine. The union of chlorine and oxygen he 

 calls chlorine acid, and its compounds, of course, 

 chlorates. This is justly reckoned one of the most im- 

 portant of Davy's many brilliant discoveries. 



It remains to make mention of the valuable present 

 which this great philosopher offered to humanity his 

 safety-lamp. The dreadful ravages made on human 

 life by the fire-damp explosions that is, the burning 

 of hydrogen gas in mines had often attracted the 

 notice of both the mine-owner and the philanthropist. 

 Various inventions had been fallen upon to give light 

 in those recesses of the earth with so low a degree of 

 heat as should be insufficient to explode the gas. One 

 of them was a series of flints playing by machinery 

 against each other so as to give a dim light ; but this 

 had very little success ; it was clumsy, and it was not ef- 

 fectual so as to cause its use by miners. The ventilation 

 of the galleries by furnaces and even by air-pumps was 

 chiefly relied on as a preventive ; but gas would collect 



