C 95 1 



continues to produce others. But this is hazarded 

 merely as a conjecture. Are there any facts fuffi- 

 ciently authenticated, which prove that a plant once 

 known to be infected with this difeafe, invariably 

 produces difeafed plants ? Or is it for certain known, 

 that in any cafe a curled potatoe has been produced 

 from a plant that was perfectly found, and not in 

 the fmalleft degree affected with that diforder? 

 Clear proofs by experiments made with the utmoft 

 caution are here wanted, and not the refult of ran- 

 dom obfervation. 



In confidering thefe queftions, and comparing 

 them with phenomena already known, it feems dif- 

 ficult to decide which way the probability lies. On 

 the one hand, feeing this difeafe is, or at leaft moft 

 certainly was, entirely unknown in many large dif- 

 tricts where potatoes have been long cultivated, it 

 would feem to favour the opinion that it only ori- 

 ginated from infected feed: — on the other hand, it 

 is afferted, as a well-known fact, that fields which 

 have been planted with feed that was in the former 

 year very little if at all affected, have been known 

 to produce plants the fucceeding year, almoft en- 

 tirely of the curled fort. Should this fact be 

 proved, it would feem to favour the oppofite hy- 

 pothec's ; but even here, we mail foon fee reafon to 

 judge cautioufly. 



Infectious 



