132 THE ATOMIC WEIGHTS. 



GLUCINUM. 



Our knowledge of the atomic weight of gkicinum is chiefly derived 

 from experiments made upon the sulphate. Leaving out of account the 

 single determination by Berzelius, * we have to consider the data fur- 

 nished by Awdejew, Weeren, Klatzo, Debray, Nilson and Pettersson, and 

 Kriiss and Moraht. 



Awdejew, f 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 SO. and GIO, but not 

 absolute weights. As, however, his calculations were made with SO3 = 

 501.165, and Ba probably = 855.29, we may add a third column showing 

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



SO.,. GIO. Ratio. 



4457 1406 921.242 



4531 1420 927-304 



7816 2480 915-903 



12880 4065 920 8 14 



Mean, 921.316, zh 1.577 



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 

 BaS04. The ratio is given in a third column,just as with the figures by 

 Awdejew : 



GIO. BaSO^. Ratio. 



.3163 2.9332 927-031 



.2872 2.6377 918 419 



■ - .• .2954 2.7342 925-592 



.5284 4-8823 902.946 



Mean, 918.497, dr 3.624 



Klatzo's§ figures are as follows, with the third column added by the 



writer : 



GiO. BaSO^. Ratio. 



.2339 2.1520 920.052 



.1910 1.7556 919.162 



.2673 2.4S72 930-490 



■3585 3-3115 923-710 



' .2800 2.5842 922.989 



Mean, 923.281, ± 1.346 



* Poggend. Annal., 8, i. 



t Poggend. Annal., 56, 106. 1842. 



i Poggend. Annal., 92, 124. 1854. 



g Zeitschr. Anal. Chem., 8, 523. 1S69. 



