BLACK BLIGHT IN WHEAT. 165 



" never materially injured by rust, potatoes are 

 " considered in its best cultivated district (the 

 " Pays de Waes) as the best preparation for that 

 ** crop. If too much dung occasion the pro- 

 ** pagation of fungi, which there is reason to 

 «* beheve is the case, smothering crops, by 

 " exhausting and diminishing the strength of 

 " the dung, may take away that tendency." 



Undoubtedly the tares, cole-seed, potatoes, &c. 

 growing on the manured soil, must reduce, if not 

 wholly consume, its gross and over-luxuriant 

 qualities, and time and exposure, effect a more 

 complete decomposition and evolution of its 

 vitiating effluvia, and thus the great cause being 

 removed, the effect must cease. 



Sir John further says, " Mr. Knight is de* 

 «* cidedly of opinion that the disease is taken up 

 •* by the root, every experiment to communi- 

 «* cate it from infected straw to others proving 

 •* abortive, and indeed if it were introduced into 

 " the ear of the plant how could it descend, and 

 " infect solely the stem, which is the case, un» 

 ♦* less when the disease is inveterate T* 



As to the fungus passing into plants by the 

 roots, or being prevented from propagating, by 

 any of the means here pointed out, it appears 

 almost too preposterous to be seriously thought ofl 



How difficult do our housewives find it, to ex» 

 M 3 



