NITROGEN. 39 



NITROOEN. 



The atomic weight of nitrogen has been determined from 

 the density of the gas, from the ratio between ammonium 

 chloride and silver, and from the composition of certain 

 nitrates. 



Upon the density of nitrogen a great many experiments 

 have been made. In early times this constant was deter- 

 mined by Biot and Arago, Thomson, Dulong and Berzelius, 

 Lavoisier, and others. But all of these investigations may 

 be disregarded as of insufficient accuracy ; and, as in the case 

 of oxygen, we need consider only the results obtained by 

 Dumas and Boussingault, and by Regnault. 



Taking air as unity, Dumas and Boussingault* found the 

 density of nitrogen to be — 



.970 

 .972 



•974 

 Mean, .972, i .00078 



For hydrogen, as was seen in our discussion of the atomic 

 weight of oxygen, the same investigators found a mean of 

 .0693, ± .00013. Upon combining this with the above 

 nitrogen mean, we find for the atomic weight of the latter 

 element, N = 14.026, ± .0295. 



By Regnaultf much closer work was done. He found the 

 density of nitrogen to be as follows : 



97148 

 97148 

 97154 

 97155 

 97108 

 97108 



Mean, .97137, ifc .000062 



* Compt. Rend., 12, 1005. 1841. 

 f Compt. Rend., 20, 975. 1845. 



