S8 Cultivation of Arable Land.JFkeat Infcfts, DcftruQfoe of. . 



power in deftroying the grub : there can be little doubt, that when applied in its 

 cauflic or moft active ftate, it will prove destructive to it, as well; as moft other 

 animals of the infect kind. It has indeed been remarked, that both hot lime 

 and alkaline falts arc capable of deftroying fuch noxious infects as feed upon 

 the roots, Hems, and leaves of field plants, by the property they poffjfs of com 

 bining with and reducing the organization of their bodies.* This effect would 

 not however feem to be produced on living animals, except where fuch fubftan- 

 ces are laid on in very large proportions, by which the crops would be in danger 

 of being deftroy ed. It is added by the fame author, that neutral fal ts may often 

 be made ufe of with fuccefs in the fame intention. 



Thefe are fuppofed to produce their deftructive effects on mails, fiugs, grubs, 

 and other limilar animals, by caufing fuch exceflive evacuations, by their power 

 ful action, that they are incapable of with Handing them. In this view it is pro 

 bable that, in the neighbourhood of the fea, fuch fand as has been constantly for 

 along time covered by the tides might be employed with advantage in the way 

 of a top-dreffing where wheat or other crops are injured by fuch animals. But 

 when either cauftic lime or fea-falt is laid on in the way of top-drefling for grain, 

 crops, in order /to deftroy the grub, when exifting at their roots, immediately! 

 below the furface of the ground, grear care mould be taken that they be not 

 poffeffed of fuch caufticity, or applied in fuch quantities, or fo unevenly, as tot 

 hurt the young plants by their too powerful operation on them. 



Soot is likewife a faline fubftance that has-been much made ufc of in differ 

 ent diftricts for fowing over young wheat and other grain crops when injured 

 by worms, grubs, or other infects that feed upon and deftroy the tender items, 

 leaves, and roots of fuch plants. It is a material which, in addition to carbo 

 naceous and earthy matters, confifts of mineral or refmous oil made capable o 

 folution in water by the large proportion of faline fubftance which it contains. 

 The folution thus formed, it is afferted, &quot; is an extremely bitter, high coloured^ 

 oily liquor, which not only poifons the infect on which it may fall, but alfo com*. 

 municates a bitter tafte to the furface of the roots and leaves of plants, thus 

 rendering them unfit for the food of fuch infects. &quot;t But the effects of this- 

 fubftance may be ufeful in other ways befides that of deftroying infects ; the 

 growth of the plants may be fo quickly promoted by the bituminous oily folu 

 tion formed by the faline principle of the foot, as to allow no time for the 

 ravages of the infects on them.J.. 



* Dimdonald s Connexion of Agriculture with Chemiftry, p. 136. 

 i Ibid,. 1 Ibid, p, 138, 



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