182 BIOGKAPHIES OF SCIENTIFIC MEN 



and carbon dioxide. His chemical and physical researches 

 were incessant, and most important discoveries were 

 made by this indefatigable genius. 



Gay-Lussac discovered the monochloride and trichloride 

 of iodine, and dithionic acid ; and " by heating sodium in 

 dry ammonia, Gay-Lussac and Thenard obtained an olive- 

 green, easily-fusible mass, sodamide, hydrogen being 

 separated. This substance with water forms sodium 

 hydroxide and ammonia ; with carbon monoxide, it 

 forms sodium cyanide and water; and with dry hydro- 

 chloric acid it forms sodium and ammonium chlorides." 



Gay-Lussac also worked on the products of the 

 explosion of gunpowder in both confined and open spaces. 

 This was the beginning of the vast province of artillery 

 science ; and his elaborate and beautiful researches on 

 the fulminates of silver and mercury were of the highest 

 order. Mercury fulminate is prepared by warming 

 alcohol with nitric acid and mercuric nitrate. It forms 

 silky, lustrous prisms, which explode with the utmost 

 violence upon being heated or struck; hence it is ex- 

 tensively used for percussion caps, dynamite cartridges, 

 etc. The analogous silver fulminate is still more 

 explosive. 



In 1831 Gay-Lussac was elected a member of the 

 Chamber of Deputies; and in 1839 he was created a 

 peer of France by King Louis Philippe. The latter's 

 education, it may be remarked, was entrusted to the 



