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alluded to, I do not take it on me to fay. In 

 matters of fuch nice difquifition as the prefent, many 

 facts obtained by very accurate obfervation are ne- 

 cefTary, before any conclufion can be relied on. 



The following accidental experiment, relating to 

 the fubjeft here in agitation, deferves to have a 

 place: — 



Experiment Thirteenth. 



In the year 1776, 1 planted with potatoes afmall plot in 

 my garden ; it accidently happened that the one half of it 

 had been in cabbages the year before, and the other half in 

 graft, which, for the fake of an experiment, had lain in that 

 ftate for three years. The foil was in every other refpecT: 

 the fame. The whole was dug over in the month of April, 

 fome loofe mould having been (hovelled up on the top of 

 that part which had been in grafs, merely to cover the 

 grafTy part of the fod. It was all planted with the fame 

 kind of potatoe on the fame day, and managed in every 

 refpecr. alike. None of it got any dung. The crop was 

 in both places very good, and nearly equal in quantity ; 

 but it was remarked, as a fmgular peculiarity, that the 

 potatoes which grew upon the part that had been in grafs 

 were remarkably meally, whereas thofe that grew upon the 

 other divifion were of a very foft and watery kind. The 

 difference between them was fo perceptible, that no perfon 

 in the family but could have told at once if the fervant 

 by miftakc at any time brought the one kind infteadof 

 the other. 



In this cafe, it is obvious, that the difference in quality 

 was produced entirely by fome peculiarity in the foil, and 



could 



