526 



PRODUCTION OF 



Sect. XVIII. 2. 15. 



called Swilcar oak, celebrated in an unpubliflied poem by Mr.Mundy, 

 on his leaving that foreft, and is there faid to be 600 years old. 



But the caudexes of buds, which compofe the barks and afterwards 

 the timber of trees, differ from the nefts or cells of the coralline in- 

 fers, which compofe their calcareous rocks beneath the waves, in 

 this circumftauce. The cells of the coralline infeds, like the fliells 

 of other fea-animals, become harder by time, changing by flow de- 

 grees the phofphoric acid, which they contain, for carbonic acid ; and 

 fome of them afterwards for {iliceous acid, and are thus converted 

 into limeftone and flint, and remain eternal monuments of departed 

 animal life. 



Whilft the remaining vafcular fyftem, after the death of vegeta- 

 ble buds, like the flefli of anim 

 chemical 



dergoes in procefs of time 



a 



decompofition, and lofes by ferment 



d putrefad 



both their carbonic and phofphoric acids, which probably o-ave them 

 their folidity, and crumble into duft ; which is {ecu in the rotten 

 trunks of trees, which lofe fo much of their carbon as they decay ; 

 and alfo become luminous, when expofed to the air by the efcape or 

 produdion of phofphoric acid. And finally, their other component 

 parts are feparated by elutriation, and form moralTcs : whence coals 



iron, clay, and fandflone 



hich are found 



th 



which 



ime-rock 



previoufly generated 



th 



ocean 



monuments of departed vegetable Jife. Wh 



d remain eternal 



it appears 



h 



a 



boundary is fet to the fize of trees by their internal decay, b 



to the growth of coral-rocks, which are fo formidable in th 

 gation of the fouthera ocean^ 



5 



^efilon on the cultivation of Timber 



The political advantage or difad 



this ifland fhould be here confidered 



a 



of cultlvatlns: timbei 



to 



In the prefent infane flate of 



human 



