SANGER-RIEGEL. — SULPHUR TRIOXIDE-SILICON CHLORIDE. 589 



Table of Complete Analyses. 



for excluding them, and if this is done, all the complete analyses of tlie 

 well-established specimens of the mixture show that it is made up of 

 pyrosulphuryl chloride and silicon oxychloride only. This inference 

 is confirmed in a number of different ways. 



The boiling-point of this fraction 135-150° is what would be expected 

 for while pyrosulphuryl chloride boils at 152.5-153°, the least trace 

 of moisture causes a considerable portion of it to boil 5° to 10° lower, 

 and the boiling point of silicon oxychloride is 136-139°.^ 



The behavior of the distillate with water also is a valuable indica- 

 tion. When much water was added to it there was a violent reaction 

 accompanied by the formation of silica, such as silicon oxychloride 

 gives, and an oily liquid separate*! and sank to the bottom of the 

 vessel, where it dissolved very slowly, showing the behavior of pyro- 

 sulphuryl chloride; dilute sodic hydrate acted in the same Ava}-. 

 As described before, the crystallization could be induced with a com- 



