250 Jsotice oj a Silicious Petrifaction. 



properly with lime, he. that a valuable and cheap water- 

 proof mortar might be obtained. 



N. B. The specimen of petrified wood is about eight- 

 een inches by six inches. It is entirely silicious, a part of 

 it resembling the coarser varieties of wood opal, generally 

 opaque white, but in some portions stained of a rust or vio- 

 let colour by oxide of iron. The wood is unquestionably 

 pine. The layers and fibres are distinctly preserved. There 

 is a knot, very exactly imitated, and on the outside of this 

 knot, there is a collection of resinous matter, such as is com- 

 mon in similar situations in decayed trees now standing. It 

 belona;ed to a dry tree, from which the bark had fallen, and 

 its surface exactly resembles the half decayed surface of dri- 

 ed trees. It is worm eaten, and the intervals between the 

 outer layers are filled with the dust deposited by the larvjeof 

 insects. Though most of the specimen, particularly the 

 firmer parts, is flinty or opaline, (there is a clear line of sep- 

 aration between the opaque white and semi-translucent vio- 

 let coloured portions of which it is chiefly composed,) yet 

 the open spaces between the layers, and particularly around 

 the knot are lined with minute quartz crystals. The spe- 

 cimen is said to have been taken from an entire tree, which 

 lately stood erect and imbedded in a hillock of loose sand. 

 It probably grew on the spot, and was killed and gradually 

 covered by the blowing sand. The specimen of the rock 

 is a sand stone cemented by oxid of iron, formed of the com- 

 mon coarse sand of the southern pine forests. Such sand 

 stones are common all over the Southern states, from N, 

 Jersey to Alabama, particularly near the borders of the 

 primitive. They form entire hillocks in the barrens oppo- 

 site Philadelphia, where they have a striking resemblance 

 to sand hardened by frost. (J. G. P.) 



