8 ATOMIC WEIGHT DETERMINATIONS. 



tic cliloride, and 0.2975 aluminic oxide. {Silliman's Ayner, 

 Journ., ^7 1835, 138, 241.) Berzelius points out the incon- 

 sistency of these data. [Berzelius' Jahresberiehi, 15, 1835. 

 138.) 



C. TissiER : ^7.12 (O = 16). 



Determined by dissolving aluminium in chlorhydric acid, 

 evaporating to dryness with excess of nitric acid and de- 

 composing the nitrate by heat. The aluminium employed 

 contained 0.135 per cent, sodium. 1.935 of this metal gave 

 3.645 oxide. [If Na = 23, these data give Al = 27.12.] 

 The metal was prepared by heating aluminic fluoride with 

 purified sodium in a graphite crucible. {Paris Comptes 

 Bend., Jfi, 1858, 1105.) ^ 



J. Dumas : 27.446 (O = 16). 



Determined by six experiments on the titration of aluminic 

 chloride with argentic nitrate. The mean result was Al = 

 13.723 (0=8) ; extreme difference 0.09. The aluminic chlo- 

 ride, which had been prepared on a large scale, was purified 

 by sublimation over iron-tilings and over aluminium filings, 

 and by a third sublimation in a current of hydrogen over 

 aluminium tilings, after which it was melted. Experiments 

 on the oxidation of aluminium were found unsatisfactory on 

 account of the difiiculty of obtaining the metal pure. They 

 gave Al at from 13.74 to 13.89. D^umas takes Ag = 108; 

 CI = 35.5. {Ann. de Chim. et de Phys., (3,) 55, 1859, 151.) 



W. Odling : 27.5 (0 = 16). 



Determined from the vapor density of aluminium methide 

 and ethide at 220° and upwards. {Phil. 3Iag., (4,) 29, 1865, 

 316.) 



— . IsNARD : 27 (O = 16). 



Pure aluminium dissolved in chlorhydric acid, evaporated 

 and heated to redness, gives y of its weight in oxide. {Paris- 

 Comjjtes Rend., 66, 1868, 508.) 



Pelouze and Fremy give 27.357 (O = 16) ; 170.98 (O = 

 100,) for the atomic weight of aluminium, and assert that 

 this value is derived from the composition of potash-alum, 

 but they give no authority for the value. The experiments- 

 were made by precipitation with barium chloride. {Traite 

 de Chimie, 3d ed., 1, 50.) 



