110 ATOMIC WEIGHT DETERMINATIONS. 



and K. All weighings reduced to vacuum. [Stas, Unter- 

 such. iiber Chem. Prop., Leipzig, 1867.) 



SODIUM. 



The specific heat of sodium has been determined by Keg- 

 nault and indicates an atomic weight of about 23. ( Gmelin- 

 Kraut, l. c.) 



H. Davy; F. H. Wollaston : £3.^8 (0 = 16) ; 145.5 

 (O = 100). 



Davy found that 134 CI combine with 88 Na to form 

 sodium chloride. If CI = 441, the value follows. (Fhil 

 Trans., m, 1814, 20.) 



J. J. Berzelius : S3J64. (0 = 16). 



Berzelius found that 100 Na CI = 244.6 Ag CI. [If Ag 

 CI = 143.387, (Stas,) the value follows.] {Poggend. Ann., 8, 

 1826, 189.) 



F..PENNY : 23.046 (0 = 16). 



Penny made four experiments on the conversion of the 

 chlorate into the chloride by means of HCl. A known 

 weight of the salt was dissolved in a flask in the acid and 

 evaporated, dried and weighed without removal. The 

 sodium chloride was not fused. The mean result was tbat 

 100 chlorate equals 54.930 chloride; extreme difference, 0.02. 

 This relation gives the molecular weight of the chloride at 

 58.5. Penny had found the atomic weight of CI = 35.454 ; 

 hence the value for Na. [If CI = 35.457 (Stas,) Na = 

 23.043. Stas himself found 23.043.] The sodium chlorate 

 was prepared by precipitating potassium chlorate with 

 sodium bitartrate, and purifying the sodium chlorate by 

 recrystallizatiou. The weighings are for vacuum. {Phil. 

 Trans., 129, 1839, 25.) 



J. Pelouze: 22.97 (0 = 16); 143.59 (0=100). 



A known weight of perfectly pure silver was dissolved 

 in nitric acid, and brought in contact with a known and 



