PRINCIPLES OF COMBUSTION. 



143 



become condensed into one volume of carbonic acid (as shown in 

 the last figure) ; and that, in the second constituent, the two vol- 

 umes (meaning double bulk) of hydrogen, and one volume of 

 oxygen, become condensed into two volumes of steam, (as 

 shown in the annexed figure.) 



other as 1 to 8. Hence, the equivalent of the atom of water will be, 1 

 hydrogen -f- 8 oxygen = 9. But oxygen and hydrogen exist in the gase- 

 ous state, and the weight of equal volumes of those gases (or, in other 

 words, their relative densities, or specific gravities) are to each other as 

 1 to 16 ; hence, 1 volume of hydrogen is combined with a volume of 

 oxygen to form 1 volume of the vapor of water, or steam : for the specific 

 gravity of steam, compared with hydrogen, is as 1 to 9. The annexed 

 diagram, therefore, will represent the combining weights and volumes of 

 the elements of water and of its vapor." 



Steam. 



or thus, 



The following is also much to the point : "La composition de 1'eau 

 cst un des elemens les plus necessaires aux calculs des chemistes, les 

 derniers experiences de MM. Berzelius et Dulong out fourni pour sa 

 composition des nombres qui sont adoptes t>ar t.ous les chemistes. Elle 

 est formee d'apres eux de 



Oxygene 88.90 1 volume, oxygene. 



Hydrogene . . . .11.10 2 volumes, hydrogene. 



100.00 1 volume eau. 



Parmi les nombreuses decouvertes que la science doit a M. Gay Lussac, 

 on remarquera toujours la belle observation sur la composition de 1'eau, 

 qui le conduisit a trouver les vrais rapports des gaz et des vapeurs dans 

 leurs combinaison. Des experiences tres exactes, qu'il avoit faites con- 

 jointement avec M. de Humboldt, lui prouverent que Ve.au formee (Pun 

 volume d'oxygene et de deux volumes de hydrogene, resultat plainement 

 confirme depuis par tous les phenomenes ou 1'eau joue un role actif, et 

 qui s'accorde avec la composition trouve par MM. Berzelius et Dulong." 

 Dumas, vol. i., p. 33. 



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