00 THE ATOMIC WEIGHT OF NITROGEN. 



that of nitrogen ; consequently, that the true 

 atomic weight of nitrogen is 7 compared with 

 hydrogen, (as maintained by Dalton and Berze- 

 lius,) instead of 14, as supposed by the majority 

 of chemists. And if such be the fact, it follows, 

 that hydrogen, carbon, nitrogen, and oxygen, 

 (which are by far the most important of all the 

 elements, because the most active, and because 

 they are the principal constituents of organized 

 bodies,) contain the same amount of caloric 

 around their chemical atoms.* 



A still more direct and cogent proof that the 

 refractive power of bodies is in proportion to the 



* There is, therefore, reason to believe, that when the refrac- 

 tive power of all bodies shall be rightly ascertained, we shall have 

 a more certain method of determining their atomic equivalents, 

 many of which are acknowledged to be doubtful ; and that we 

 shall be able to correct errors in regard to the chemical compo- 

 sition of bodies, that have arisen from imperfect analyses. It 

 must, however, be admitted, that in the present state of science, 

 the refractive power of compound gases, liquids, and solids, does 

 not always correspond with that of their constituents in the se- 

 parate state; a circumstance which may be owing in part to 

 imperfect experiments, and partly to the fact, that during nearly 

 all chemical combinations and decompositions, caloric is either 

 absorbed or given out, as will be shewn hereafter. But as we 

 have found that in hydrogen, carbon, and oxygen, it coincides 

 so nearly with the quantities of caloric they give out during com- 

 bustion; and is nearly the same in several compound gases, 

 when deduced from the refractive power of their elements, the 

 subject is one that merits the most careful investigation. For if 

 there be no uniform ratio between the refractive power of bodies 

 and their specific gravities, while in the best ascertained cases, it 

 accords with the quantities of caloric they afford by combustion, 

 it is difficult to resist the conclusion that caloric is the cause of 

 refraction, as it is of attraction and repulsion. 



