DOMAIN II. SILICEOUS. 223 



MODE XIV. SILICEOUS GLUTEN1TE. 



This division will comprehend many import- Description, 

 ant substances of various structures, from the 

 celebrated Egyptian bricia, containing large 

 pebbles of jasper, granite, and porphyry, to the 

 siliceous sand-stone of Stonehenge. The glu- Origin, 

 tenites are of various formations ; and the pud- 

 ding-stone of England would rather seem, as 

 already mentioned, to be an original rock, the 

 pebbles or rather kernels having no appearance 

 of having been rolled in water. Patrin* has 

 expressed the same idea concerning those pud- Pudditig : stone 

 ding-stones which so much embarrassed Saus- 

 sure, as he found their beds in a vertical posi- 

 tion, while he argues that they could only have 

 been formed on a horizontal level. This curious 

 question might, as would seem, be easily decided 

 by examining if the kernels have been rolled, or 

 if, on the contrary, they retain their uniform 

 concentric tints, observable in the pudding-stone 

 of England, and well represented in the speci- 

 men which Patrin has engraved. But the same 

 Idea had arisen to me before I had seen Patrin's 



* i. 164. 



