PRINCIPLES OF COMBUSTION. 



335 



umes of hydrogen and one of carbon vapor; the gross bulk 

 of these three being condensed into the bulk of a single atom of 

 hydrogen ; that is, into two fifths of their previous bulk, as shown 

 in the annexed figures. Let figure A represent an atom of coal 

 gas — carburetted hydrogen — with its constituents, carbon and 

 hydrogen ; the space enclosed by the lines representing the rela- 

 tive size or volume of each ; and the numbers representing their 

 respective weights — hydrogen being taken as unity both for vol- 

 ume and weight."^ 



Carburetted Hydro ge7i. Bi-carburetted Hydrogen, 



1 atom of 



the above gas, 



weight 8. 



1 atom of 



the above gas, 



weight 14. 



Its 

 constituents. 



* '' Ce gaz (carburetted hydrogen) est compose de 75.17 parties (by 

 weight) de carbone, et 24.33 d'hydrogene ; ou, d'un volume de carbone 

 gazeiix et quatre volumes de gaz hydrogene, condenses a la moitie due 

 volume de ce dernier, ou, aux 2/5 du volume total du gaz, de maniere 

 que de cinq volumes simples, il n'en resulte pas plus de deux de la com- 

 binaison." — Berzelius, vol. i., p. 330. 



12=^ 



