1803. Anfwers to ^teries on Vegetaticn» 52 



crop, it would be ftill more fo. Potatoes, cabbages, &c. maj, 

 with propriety, be cultivated in young tree-plantations, for four or 

 five years, or till the roots of the trees begin to come into contucl 

 •with one another, but not longer ; becaufe, if peihfted in after 

 that time, the extreme fibrils, which are the purveyors of the 

 plant, might be materially injured 



5. Firjly Of courfe, yes. Secondly, The foil is alfo much bene- 

 fited by this fpecies of fallow. 



6. By anv procefs of ploughing, and harrowing, that I have yet 

 witnelVed, no. 



7. Much muft depend on the quality and the fituation of the 

 land, and the ftate of labour ; the dilference of expence may be 

 from 20 to 30 Ihillings per acre 



8. 1 believe it would, in many cafes ; and I am convinced, that, 

 in all cafes where the depth of good foil is greater, or beyond the 

 reach of the plough, trenching with the fpade, once in four or five 

 vears, would anfwer the expeccations of the moft fanguine. 



Vil. Concerning Suhjlances in the Earth, injurious to Vegetation, 



Anf. to QjLief. I. Metallic, fulphureous, aluminous, and all af- 

 trin^ent fubllances are inimical to vegetation ; and foils wherein 

 thefe are found, are more or lefs fertile, according to the quantitj 

 of metal, &:c. they contain. Their effects on the tender roots of 

 plants, in corroding and cankeriag them, are fuch as frequently 

 occafion decay, ficklinefs, and diffolution. 



2. PulveriTiation, expofition to the elements, and the addition of 

 diffolvent matter, as lime, chalk, &c. 



3. Firjl, Yes. Secondly, By judicious draining, and afterwards 

 treating it, as above, as the cafe may require. In many cafes, alfo, 

 it is neceiTary, and in all cafes proper, to add adhefive and more 

 ponderous matter in the cultivation of peat-mofs. 



4. A mixture of peat- earth, purged of its noxious qualities, 

 with loam, &c. is found generally to fuit their nature, as more im- 

 mediately refembling the foil of their nativity. There are many 

 European, and even Britifh plants, which alfo thrive beft in this 

 kind of foil ; and there are many American and other foreign 

 plants that do not. 



5. When trees are obferved to decay, from their roots having 

 reached a cankering metallic llratum, I think it is then time to Hub 

 them up, as I have not been yet able to difcover a cure j and I 

 had rather fee no tree than fee a fickly one. 



VIIL 



