Alaric/icstfr Meinoirs, I W. xhii. (1902), No. 3. 1 1 



In all the experiments in which lime water was in 

 contact with powdered glass, the very bulky and flocculent 

 precipitate resulting was ver}- noticeable after six or eight 

 weeks contact, still more after very prolonged contact. A 

 similar precipitate is noticeable, but not nearly so distinctly, 

 when strontia and baryta solutions are left in contact with 

 powdered glass. Fig. i shows the appearance of three 

 flasks containing lime, strontia, and baryta water respec- 

 tively, in contact with powdered glass for a period of nine 

 months. Unaltered powdered glass is seen both in the 



Fig I. 

 strontia and baryta water flasks, but in the case of the 

 lime water flask the action went on so completely that no 

 particles of glass appeared to remain, although in the early 

 stages the powdered glass is easily distinguished from the 

 flocculent precipitate by its greater densit}' and shining 

 appearance. The precipitate cannot be expected to be very 

 definite in composition, but a quantity was obtained for 

 analysis, separated as completely as possible from the 

 powdered glass and thoroughly washed. It was dried at 

 i20-'C.,and then appeared as a nearly white powder, easily 



