BERYLLIUM. 17 



In a calorimetric apparatus constructed for the purpose, the 

 amount of heat given off during cooling by 108 parts of 

 silver heated to 100° was found to be equal to that commu- 

 nicated by a little more than 9.2 parts of beryllium under 

 the same conditions. Assuming the atomic weight of 

 the metal to be 9.2, the atomic heat found would be 5.91. 

 The smallness of this number the observer accounts for by 

 supposing that there was a trace of platinum present intro- 

 duced b}' the use of platinum vessels in the course of re- 

 duction. {Phil. 31ag., (5,) 3, 1877, 38.) 



J. J. Berzelius : 14-^ (0 = 16). 



Berzelius analysed the salt formed by saturating dilute 

 sulphuric acid with beryllium oxide. From the amount of 

 barium sulphate obtained he inferred that the atomic 

 weight of beryllium was 331.261 on the supposition that 

 the oxide was BCj -|- O3 and that the salt was neutral. Ber- 

 zelius took O = 100; S = 200.75, and Ba = 855.29. [Awde- 

 jew having discovered that this salt is basic, this value is 

 reduced to 90.63 ; or, for = 16, to 14.5.] Berzelius 

 accepted Awdejew's determination in preference to his own. 

 [Poggend. AnnaL.S, 1826, 187 ; and Lehrbuch der Chemie, 5th 

 ed., 3, 1225.) 



T. Thomson: 36 (0 = 16). 



Experiments not given. The value is four times nine, 

 and may have arisen from a mistake as to saturation. 

 {Sgstem of Cliem. 7 ed., 1, 1831, 459.) 



— . AwDEJEW : 13.85 (O = 16) ; 86.58 (0 = 100). 



Beryllium sulphate, in chlorhydric acid solution, was de- 

 composed with barium chloride. In the filtrate the excess 

 of barium chloride was precipitated with sulphuric acid, 

 and the beryllium oxide thrown down with ammonia, dried, 

 heated, and weighed. The beryllium sulphate was prepared 

 from pure carbonate by treatment with sulphuric acid and 

 precipitation with alcohol. It was purified by recrystalli- 

 zation. Four experiments were made, the mean of which 

 calculated for S = 201.165, gave Be = 58.084 with an ex- 

 treme difference of 1.955. {Poggend. Annal., 56., 1842, 106.) 

 Weeren recalculated these analyses for S = 200 and got 

 57.^2, [or f of 86.58.] {Poggend. Annal, 92, 1824, 124.) 



