SO WILLIAM GOSSAGE 



lime and caustic soda. The silicate of lime 

 thus formed was found to have a peculiar 

 value as a manure. Other uses to which 

 "liquid flint," as those soluble alkaline sili- 

 cates are sometimes termed, was applied, are 

 to render impermeable to water, bricks, 

 stone, wood, paper hangings, and distemper 

 colouring, also to produce waterproof fabrics. 

 The last great effort to which Mr. Gossage 

 applied himself was to obtain the alkaline 

 silicates by passing the vapours of the 

 chlorides into a tower or stack filled with 

 flints, which were heated to an intense heat. 

 When the volatilised chlorides came in 

 contact with the glowing flints, they were 

 decomposed, silicate of soda or potash was 

 formed, and hydrochloric acid was evolved. 

 The apparatus resembled a small blast 

 furnace, at the base of which were three or 

 four gas producers, such as Siemens applied 

 to his gas furnaces. The gases were ignited 

 just before entering the tower; they passed 

 over a bed of chloride of sodium, which, by 

 the intense heat of the flame, was volatilised ; 

 the gases of combustion and the chloride 

 vapours passed up into the shaft filled with 

 flints. These were heated to a white heat, 

 and silicate of sodium was formed, which ran 



