•^38 MK. J. B. HAXNAY ON SILICEOUS FOSSILIZATIOX. 



water, even when the temperature rose to 150° C. A 

 fractured rod (fig. 2), thus rendered traiisparent, shows on 

 the fracture plain markings of the layers composing the 



rod cylindrically arranged. It was found that when a rod 

 was heated with water in a tube to 150° for five or six 

 hours, the side of the rod next the glass became dissolved, 

 this action seeming to be due to the solvent action of the 

 soda of the glass, as water at that temperature decomposed 

 the glass, removing the alkali. Fig. 9 shows a rod so 

 treated; and fig. 13 shows a section of that rod through 

 the dotted line in fig. 9. This action clearly shows at 

 least four layers in the rod. Fig. 15 shows the action of 



