I ^S3 1 



grown on poor land, with lefs dung, they have no 

 curled plants. On the contrary, when they bough; 

 rich and large potatoes^ for feed, they have been 

 curled in great quantities. He believes, the rich- 

 ncfs and largenefs of the feed to be the caufe of 

 the evil J for he does not remember to have fcen 

 a curled ftcm which did not fpring from a fet of 

 ^ large potatoe. 



LETTER XVII, 



THIS writer apprehends the curled difeafe in 

 potatoes to proceed from a defedt in the planta 

 Jmlnalis or feed-plant j and from comparing curled 

 ones with others, there appeared to be a want of^ 

 or inability in, the powers of expanding or un- 

 folding the parts of the former ; which, from this 

 defed, forms Ihrivelled, ftarved, curled ftems. On 

 examining fome of the fets, at the time of get- 

 ting in the crop, he found them hard and unde- 

 cayedi fo hard indeed, that fome of them would 

 not be foft with long boiling. This led him to 

 think that fome manures might have the fame ef- 

 fcdb on them as tanner's ooze has on leather, and 

 fo harden them that the embryo plant could not 

 come forth with egfci but a clofer examination 

 taught Kim ptherwife, and that they grow equally 

 in all manures. 



Some 



