ATOMIC WEIGHTS 67 



Several other ratios are calculable from the data given, and, indeed, 

 were computed by Guye and Fluss; but they are not needed here. They 

 involve to a greater extent the uncertainties due to the losses from the 

 initial substance. The values found in this series of analyses may now 

 be combined with those obtained in the preceding sections of this work, 

 as follows : 



N. 



Previously found N = 14.0074, ± .00018 



From NOCl N = 14.006, ±.0017 



General mean N = 14.0074, ± .00018 



CI. 



Previously found ^ CI = 35.4637, ± .00042 



From NOCl CI = 35.468, ±.0010 



General mean CI = 35.4643, ± .00039 



THE RATIO HCl : NHg. 



Julius Thomsen,^ for the purpose of fixing indirectly the ratio H : 0, 

 has made a series of determinations of the ratio HCl : NHg, which may 

 properly be used toward establishing the atomic weight of nitrogen. 

 First, pure, dry, gaseous hydrochloric acid is passed into a weighed 

 absorption apparatus containing pure distilled water. After noting the 

 increase in weight, pure ammonia gas is passed in until a very slight 

 excess is present, and the apparatus is weighed again. The excess of 

 JSTHg, which is always minute, is measured by titration with standard 

 hydrochloric acid. In weighing, the apparatus is tared by one of similar 

 form, and containing about the same amount of water. Three series of 

 determinations were made, differing only in the size of the absorption 

 apparatus; so that for present purposes the three may be taken as one. 

 Thomsen considers them separately, and so gives greatest weight to the 

 experiments involving the largest masses of material. I give his weigh- 



TTCl 



ings, and also, as computed by him, the ratio ^^ • 



' Not including' addenda. 



'Zeitsch. physikal. Chem., 13, 398. 1894. For a criticism of Thomsen's work, see Acree and 

 Brunei, Amer. Chem. Journ., 36, 117. The ratio, as determined, is of small value. 



