92 ATOMIC WEIGHT DETERMINATIONS. 



to one another as 16 to 14. {Erdmann's Journ. fur Prak. 

 Chem., 8, 1836, 375; Records of General Science^ by R. D. 

 Thomson, 1836, 179.) 



F. Penny : 14.018 (O = 16). 



From the mean of three series of experiments (vide 

 Penny's determination of potassium) it follows that 100 

 potassic chloride = 135.636 potassic nitrate. Penny found 

 the molecular weight of KCl = 74.527 ; hence the difference 

 between a chloride and a nitrate is 26.560. Similar experi- 

 ments were made on the sodium salts. In four experiments 

 100 sodium chlorate were found = 54.930 chloride ; extreme 

 difierence, 0.02. In three experiments, 100 sodium chlo- 

 rate were found = 79.882 sodium nitrate; extreme difier- 

 ence, 0.015. In six experiments 100 sodium nitrate were 

 found = 68.771 chloride ; extreme difference, 0.013. In 

 seven experiments 100 chloride were found ^= 145.416 

 sodium nitrate ; extreme difference, 0.016. These data 

 give sodium chloride = 58.5, and the nitrate = 85.068, or 

 the difference between a chloride and a nitrate = 26.568. 

 Penny found 01 = 35.454. If NO3 - CI = 26.564, N = 

 14.018. Weighings for vacuum. {Phil Trans., 129, 1839, 25.) 



L. SvANBERQ : 13.91 (O = 16). 



Determined by four experiments on the decomposition of 

 plumbic nitrate by heat which gave a mean of 67.4016 per 

 cent, oxide ; extreme difference, 0.0087. [If Pb = 206.926 

 (Stas) the value follows.] {Berzelius^ Jahresbericht, 22, 1842, 

 38.) 



C. Marignac: U.02 (0 = 16); 87.625 (O = 100). 



Marignac made five experiments by dissolving a known 

 weight of silver in nitric acid and melting and weighing 

 the nitrate formed. The silver carried out of the retort by 

 the vapors was precipitated and determined. The mean 

 result was that 100 silver = 157.430 nitrate ; extreme 

 difference, 0.046 ; or, if Ag = 1349.01, N = 87.535. Six 

 experiments were made by the decomposition of a known 

 weight of argentic nitrate with a know^n weight of potassic 

 chloride by Pelouze's method. Mean, 100 KCl = 227.986 

 argentic nitrate ; extreme difference, 0.18. This gives N = 

 87.685 if K = 488.94 and CI = 443.2. Seven experiments 

 by the same method showed that 100 silver dissolved in 

 nitric acid = 49.522 ammonium chloride : extreme differ- 



