On Smut 'hi Wheat. 



loured powder; who knows but a third species of fun- 

 gus may produce the black powder, which constitutes 

 the smut? And the mushroom tribe be found more in- 

 jurious to grain than has yet been imagined? 



The time of blooming is the critical period at which 

 the smut first begins to shew itself, and then proceeds 

 rapidly, as Mr. Young observes, converting part of the 

 ear into chaff, or preventing the grain coming to matu- 

 rity. For whatever may be the hidden source of the 

 smut, the proximate cause of scanty crops of grain, fre- 

 quently consists in an imperfect impregnation at the 

 time of flowering. For according to the impregnation, 

 the grain will be either plump, shrivelled, or entirely 

 abortive. Heavy rains with high winds, at this season, 

 by washing off* a part or the whole of the pollen, des- 

 tined for fecundation, generally cause a scarcity in the 

 ensuing crops. If the pollen be consumed or vitiated 

 by insects or fungi, a proportionable failure will take 

 place. On the other hand, a calm, dry fiow^ering sea- 

 son is favourable towards a full and perfect impregna- 

 tion. Hence, when the spring proves dry, and wells and 

 rivulets sink to a low ebb, the British wheat harvest is 

 generally abundant. Here permit me to propose ano- 

 ther experiment. 



Exp. 4. Let a portion of smut be sprinkled on the 

 centre of the flower, and let the same be performed on 

 rye, barley, oats and other grain in the blooming season, 

 to determine whether the disease can be propagated b}' 

 inoculation. If the wheat should acquire the smut, it 

 proves the contagious nature of the disease, if all the 

 other kinds of grain should resist it, it will confirm the 

 opinion of its being more incidental to wheat; accord- 



