148 ON THE NATURALIZATION OF PLANTS. 



Inftruftioui. cording to their thicknefs; ftirT clay or fandy loam, as beans, 

 peach, and apple trees; robuft fpongy roots which have a 

 tendency to mat near the fur face with thin leaves, as the alder 

 (betula dims), willows (falix), require a fomewhat (tiff foil 

 with moifiure ; many of the falix genus will not grow with 

 their accuftomed vigour, in a light turfy or peat mold foil, for 

 want of the neceflary refiftance to the roots, although fuitable 

 in refpect to moifiure. Slender, hard and wiry roots, as thofe 

 of the pine, ciftus, &c. require dry, fandy, or gravelly foils. 

 And extremely fine and hairlike roots, as thofe of erica, hal- 

 mia, rhododendron, &c. muft have a foil whole particles will 

 not impede the (hooting of their tender fibres, and with a fmall 

 but regular degree of moifiure, that the roots, which by their 

 form cannot refill: the flighteft drought, may not be deflroyed. 

 Plants in a warm climate perfpire more than in a cold one ; fo 

 in a warm they require much, and in a cold one little moifiure. 

 Therefore, when tranfplanled from a warm to a cold climate, 

 they mould have a dryer foil, and from a colder to a warmer, 

 a moifter one, than their native ftation. 



In tranfplanta- In the firft cafe, not being able to perfpire the fuperabun- 



tion to a cold Jant moifiure, they will be rotted : and in the Iaft, not having 

 climate the foil .. . _ * J . • ; •■ ' , ,-■ • i 7 



muft be dryer; moiiture iuflicient to lupply the lots by perlpiration, the growth 



and the contrary. w iH be flow, difeafe and death will follow, unlefs they receive 

 a timely fupply of moifiure : by the red or yellow colour of 

 the leaves we may difcern the approach of the firll evil, and 

 by the flunted growth, and fmall curled leaves, that of the 

 laft. A large quantity of pure circulating fluid feldom injures 

 plants, but flagnant water is certain deftru&ion to almofl every 

 vegetable. 

 Local fibration After having determined the mod fuitable foil, we muft 

 or expofureisof afterwards ftrive to give each plant a proper fituation. It is 

 auence. we ^ known, that plants from a fhady will not thrive well in 



an open, nor plants from an open in a fhady fituation. But 

 the neceffity of a natural fituation is by no plant more evidently 

 illuftrated than by the common myrtle (myrtus communis), 

 Even at Glenarm, in the latitude 54° 56' N. it grows with 

 great luxuriance contiguous to the fea, and braves our coldeft 

 winters ; yet all attempts to naturalize it in an inland fituation, 

 feveral degrees farther fouth, and in a much more genial cli- 

 mate, have hitherto proved unfuccefsful. The olive tree 



cannot 



