282 



Essays. 



tages from the extensive cultivation of certain plants which cannot be 

 successfully cultivated in the open air in Great Britain, some of which have 

 been already naturalized in this island, such as the vine, the mulberry, the 

 castor-oil plant (Siciinis communis) , the olive {Olea europcea), the cochineal 

 cactus {Opuntia sp.), the tobacco, and the maize, the last both for the sake 

 of its spathes and leaves for paper-mating {for ivJiich it seems admirably 

 adapted), as well as for its grain. The northern parts of this island, 

 especially the warm climate and rich volcanic soils north of the Thames, 

 Avill doubtless produce wine and oil in abundance, and perhaps silk, as the 

 climate is well known to be suited to the mulberry, and the European olive 

 might be advantageously grafted upon the several indigenous olives of the 

 island. Further, it is not improbable that cochineal, cinchona, and coffee 

 may also be successfully cultivated in the warm climate of the northern 

 districts, seeing these two last-mentioned plants have very near botanical 

 relations in the many species of the genus Coprosma, everywhere common 

 and flourishing amongst us. Those parts of the island possessing limestone 

 soils, and, at the same time, not below the necessary isotherm, seem admir- 

 ably adapted for raising tobacco, a plant which, like clover and lucerne, 

 requires a deal of lime in the soil to bring it to perfection, its ashes 

 containing more than 20 per cent, of lime and magnesia salts ; while the 

 more equable and temperate climate and rich alluvial soils of the southern 

 parts of the island will also continue to produce and export, as heretofore, all 

 British grain and fruits and edible roots very abundantly : — 



Hie segetes, illic reniuut felicius uvse ; 

 Arborei fetus alibi, atqiie injiissa virescuut 

 G-ramina." — 



-ViEG. Georg. 1. i. 



A Comparative Table oe Weight and Specific G-eavity. 





Weight per 



Speciiic 





Name of Wood. 



cubic foot. 



Gravity. 



Eemarka. 





lb. oz. 







English Oak ... 



40 14 



•654 



Epping. 



Do. 







39 



•625 



Sussex. 



Do. 







40 10 



•714 



Wandsworth. 



American Oat ... 







42 9 



•681 





Eufflish Beecli ... 







41 2 



•658 



From Oxfordshire. 



Do. 







27 6 



•438 



Fi'om Epping. 



Eiga Fir 







37 10 



•602 





Malabar Teak ... 







37 14 



•606 





Ceylon Teak 







47 3 



•755 





