ATOMIC WEIGHTS 207 



GLUCINUM. 



Our knowledge of the atomic weight of gluciniim is derived from ex- 

 periments made upon the sulphate and three organic salts. Leaving out 

 of account the single determination by Berzelius/ we have to consider 

 the data furnished by Awdejew, Weeren, Klatzo, Debray, ISTilson and 

 Pettersson, Kriiss and Moraht, and Parsons. 



Awdejew/ whose determination was the earliest of any value, analyzed 

 the sulphate. The sulphuric acid was thrown down as barium sulphate; 

 and in the filtrate, from which the excess of barium had been first re- 

 moved, the glucina was precipitated by ammonia. The figures which 

 Awdejew publishes represent the ratio between SO3 and GIO, but not 

 absolute weights. As, however, his calculations were made with SOs = 

 501.165, and Ba probably = 855.39, we may add a third column showing 

 how much BaSO^ is proportional to 100 parts of GIO : 



Mean, 921.316, ± 1.577 



Hence Gl = 9.337. 



The same method was followed by Weeren and by Klatzo, except that 

 Weeren used ammonium sulphide instead of ammonia for the precipita- 

 tion of the glucina. Weeren' gives the following weights of GIO and 

 BaSO^. The ratio is given in a third column, just as with the figures by 

 Awdejew : 



1 Poggend. Annal., 8, 1. 

 2Pog-gend. Annal., 56, ' 106. 1842. 

 'Poggend. Annal., 92, 124. 1854. 



