166 ON THE RUST OR 



elude the seeds, , or prevent the fungus, growing 

 on their pickles and preserves, even by tied 

 down bladders and tight corks ? And if horse- 

 dung in a mass be placed in certain situations, 

 it is well known that even the large edible mush- 

 rooms will rise and grow where they never were 

 seen before. 



Thus, then, if the cause of the rust or black 

 blight be as I have stated, and the observations 

 both of Sir John Sinclair and Mr. Knight con- 

 firm my opinions, and the observations of Sir 

 Joseph Banks do not controvert them, the 

 remedy is simple and obvious : viz. for the pro- 

 duction of seed crops j let manuring follow, and 

 not immediately precede them ; or at any rate, 

 dung should not be ploughed in, on such lands, 

 immediately before sowing the seeds. 



And it i& equally obvious, that the ploughing 

 in, green crops, must be conducive to the produc- 

 tion of rust. And the feeding off turnips with 

 sheep, or folding them on the land, immediately 

 before sowing, must have a strong tendency to 

 the same effect. 



If, when lands are manured, two or three 

 succulent or green crops be taken off, before it is 

 sown for seed-crops, although the leaf and plant, 

 or straw or haulm, of such crops may not appear 

 so luxuriant in consequence, the seed will be 



