DAVY. 117 



The long labour thus ending in so mighty a result, 

 and the excitement naturally enough produced in an 

 irritable habit, threw him into an illness of a most 

 serious complexion. For many days he lay between 

 life and death in a low nervous fever, and it was not till 

 the following March that he could resume his inquiries 

 into the composition of the alkaline earths. It is to 

 the credit of chemists that no one deemed himself at 

 liberty to interfere with him, as any one might now 

 by only following his footsteps have done, and thus 

 analysed these earthy bodies. He himself, early in 

 the summer following his illness, had reduced lime, 

 magnesia, strontites, and barytes. In these experiments 

 he was greatly assisted by the ingenious contrivances 

 which Gay-Lussac and Thenard had recently used for 

 the reduction of the alkaline oxides. The metals thus 

 discovered were not any wise light or fusible like 

 potassium and sodium ; but they burnt with a bright 

 light on being exposed to considerable degrees of heat, 

 and they decomposed water ; and either by their com- 

 bustion, or their exhibition to water, they reproduced 

 the alkaline earths. 



A number of other experimental researches led 

 Davy to new and curious observations on the constitu- 

 tion and habits of different substances. But we need 

 only mention the most important of these, for it was 

 a discovery very unexpected both by himself and the 

 chemical world at large. The acid hitherto called oxy- 

 genated muriatic, or oxymuriatic, on account of its 

 powerful acid qualities, had been always from thence 

 supposed to contain an excess of oxygen, believed to 

 be the acidifying principle. At last Gay-Lussac and 

 Thenard, in 1809, concluded from some experimental 

 researches, or rather they suspected, that it might be a 

 simple and elementary substance ; but they on the whole 

 still inclined to think it contained oxygen according to 

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

 course of satisfactory experiments which have fixed the 



