ATOMIC WEIGHT OF SILICON'. 



251 



A new distillation system can now be sealed on at M and the process 

 repeated. 



Sample I. All the details of the fractionation of Sample I are 

 shown in Figure 2. The chloride was freed from suspended material 

 by filtration through glass wool and was admitted to the exhausted 

 bulb A together with several cubic centimeters of mercury. After 

 standing for a week with occasional shaking, in order to remove the 

 excess of chlorine as mercurous chloride, three small fractions, a, b, c, 

 were removed and all but about one fifth the original chloride was 

 distilled into B. From B about four fifths of the product was dis- 



W f D \ c ha 



21 20 



2 1 



SiCI 4 II 



Figure 2. 



tilled into C, after sealing off the liter reservoir E, and finally all the 

 material was collected in fourteen small bulbs, 1-14. The appearance 

 of a bulb sealed off for analysis is shown at g (Fig. 1). In the figures, 

 special joints are represented as at j, expansion reservoirs as at E, 

 more volatile fractions to the right of the center, a, b, c, less volatile 

 fractions to the left of the center, d, e. The volumes of the fractions 

 are indicated roughly by the size of the circles. Fractions 3, 6, 9 and 

 12 were analyzed. 



Sample II. Figure 2 shows diagrammatically the fractionation of 

 Sample II. After standing over mercury for some time, three small 

 light fractions, a, b, c, were removed with liquid air and the greater 



