70 THE ATOMIC WEIGHTS. 



to calculate the atomic weight of nitrogen. Let us first collect and num- 

 ber these ratios : 



(I.) Ag : AgNOg : : lOO : 157.479, ± .0003 



(2.) AgNOg : AgCl : : loo : 84.3743, ± .0025 



(3.) AgNO, : KCl : : 100 : 43.8715, =t: .0004 



(4.) AgNOg : NH^Cl : : 100 : 31.488, ± .0006 



(5.) Ag : NH^CI : : 100 : 49-5983, ± .00031 



(6.) Ag : NH^Br : : 100 : 90.8299, ± .0008 



(7.) KCl : KNO3 : : 100 : 135.636, zh .0007 



■ (8.) KCIO3 : KNO3 : : 100 : 82.500, ± .0012 



(9.) NaCl : NaNOg : : lOO : 145 418, zb .001 1 



(10.) NaClOg : NaNOg : : 100 : 79.8823, ± .0029 



(11.) NH3 : HCl : : i.oo : 2. 1394, i .000053 



From these ratios we are now able to deduce the inolecular weight of 

 ammonium chloride, ammonium bromide, and three nitrates. For these 

 calculations we must u^e the already ascertained atomic weights of oxy- 

 gen, silver, chlorine, bromine, sodium and potassium, and the molecular 

 weights of sodium chloride, potassium chloride, and silver chloride. The 

 following are the antecedent values to be employed : 



Now, from ratio number five we get the molecular weight of NH^Cl = 

 53.124,, ± .0016, and N = 13.945, ± .0051. 



From ratio number six, NH.Br = 97.286, ± .0029, and N = 13.942, 

 ± .0077. 



From ratio number eleven, NH3 = 16.911, ± .0048, and N = 13.911, 

 ± .0048. 



From ratio number four, which involves an expression of the type 

 A : B : : C + •'''' : 1^ + 2;, an independent value is deducible, N = 13.935, 

 ± .0073. 



For the molecular weight of silver nitrate there are three values, 

 namely : 



From (i) AgNOg = 168.673, ± .0049 



From (2) " ^ 168.634, rb .0066 



From (3) " ^ 168.731, zb .0046 



General mean AgNOg = 168.690, zb .0030 



Hence N=: 13.945, ± .0044. 



