26 



On the Atomic Theorrj, 



volumes of other substances, but this would subject us to 

 the serious inconvenience of giving a varying size to the 

 same substance, in its different combinations. 



Let us now state the advantages which arise from con- 

 sidering water, as composed of two atoms, hydrogen, united 

 to one atom oxygen, which theory' has been adopted by Sir 

 H. Davy in Great Britain, Berzelius in Sweden, and Gay 

 Lussac, and Thenard in France. 



The theory of volumes, which has been so ably illustrated 

 by Gay Lussac, will then coincide with the theory of atoms, 

 and the same numbers may be applied on either hypothesis; 

 it of course destroys the necessity, which has heretofore ex- 

 isted, of dividing the volumic representative of any sub- 

 stance by two, in order to obtain the atomic equivalent. In 

 this mode, much complexity of ideas, and of language, will 

 be avoided in treatises on chemistry. 



It will also be perceived, that the numbers representing 

 the atoms, or volumes of substances, will approach very near 

 to their specific gravity. From the coincidence, in many 

 well authenticated instances, it is probable, that, on more 

 accurate investigation, the specific gravity, and atomic 

 weight, and volumic weight, will correspond with each oth- 

 er in every simple substance. By the Daltonian hypothesis, 

 the representative number of the atom of oxygen, was eight, 

 of nitrogen, fourteen ; thus the atomic weight of the latter, 

 was nearly twice as great as that of the former, although its 

 specific gravity is much less — other instances of a similar 

 kind might be adduced. 



It may be supposed, a matter of slight importance, 

 whether water is composed of two atoms hydrogen, and one 

 atom oxygen, or one atom of each, but when it is known 

 that the whole fabric of chemical equivalents rests on these 

 as a foundation, and that an alteration of these numbers, af- 

 fects the whole scale of substances, it will then be consider- 

 ed a subject of importance. 



Chemical Equivalents. 



Hydrogen. 

 1. 





Oxygen. 

 10. 





Carbon. 

 12. 





Nitrogen. 

 14. 



















(Sulphur. 



1 32. 





Chlorine. 

 36. 





Iodine. 

 125. 





Phosphoru 



24. 



s. 



