THEORIES OF THE POTATO-ROT. 41 



mildew. I do not think that the changes of weather have 

 any thing to do with the potato-rot. We must have had 

 the same peculiarities of climate and weather that we have 

 now, as long ago as when I was a boy, when the potato-rot 

 was unknown. I think the gentleman is entirely wrong in 

 his theory. 



Mr. Wetherell of Boston. I rise to ask a question of 

 Mr. Ware touching the potato-rot ; and I wish to give a fact 

 on which I predicate the inquiry. A farmer in Hadley told 

 me that he raised a crop of potatoes in this wise : one half 

 the field was manured with barnyard-manure, and the other 

 half with the stems of tobacco, cut up, and used as manure 

 in the hill ; and the part where he used the manure rotted 

 badly, while the part where he used the tobacco-stems did 

 not rot at all : and, inasmuch as the same atmosphere over- 

 hung both sides of the field alike, if it was filled with spores, 

 as we are told, why did not the spores affect the crop where 

 the tobacco was used, as well as the crop where the barnyard- 

 manure was used? And, furthermore, I would ask the 

 gentleman whence come those spores that he speaks of, that 

 float in the atmosphere. 



Mr. Wake. In the first place, I will suggest an answer 

 to Mr. Hill. I know, that, a number of years ago, the potato- 

 rot was not known in this country. The probability is, that 

 the variety of fungus that produces the potato-rot had not 

 then been introduced into this country. It is a vegetable 

 growth ; and there are a number of varieties of fungi, and 

 that peculiar variety which produces the potato-rot very 

 likely had not been introduced into this country at that time. 

 With regard to the crop of potatoes, where one part was 

 planted with tobacco, and the other with manure, I would 

 like to know if the gentleman knows that both parts of the 

 field came forward alike. Did the manure force the crop 

 along a little more rapidly than the tobacco-stems, or did the 

 tobacco-stems force the crop to come forward a little before 

 the manured part? If there was any difference in either 

 coming forward, when that part of the croj^ that was manured 

 with barnyard-manure was in just the right condition, proba- 

 bly we had the kind of weather that was particularly adapted 

 to the propagation of the spores that produce the potato-rot. 

 If that was not the case, I can only say that I suppose tobacco 



