No. 105.] 367 



of the pits were nearly all fallen in, and the whole fast becoming a 

 mass of putrefaction. 



Query 17. — What is your opinion of the cause of the disease 1 



On- this subject, as might be expected a great diversity of opin- 

 ion exists. Some ascribe the disease to electricity, some to atmos- 

 pheric influence, some to a wet season, some to wet, drought and 

 frost, combined, some to insects or animalculse, some to ruptures of 

 the cells, some to decomposition of proteine, others to fungi, others 

 to a diseased and vitiated constitution in the potato, weakened by 

 long and high cultivation ; others unite nearly all of the above ; others 

 still ascribe it to a direct visitation of Providence ; and yet another 

 class declare that they know nothing about it. I think these last are 

 the safest at present. 



Liebig, as I have before said, considers that the casein, or some ana- 

 logous proteine compound which he has found in the potato is the cause 

 of the disease ; it being peculiarly liable to decomposition, he thinks 

 that some peculiar state of the atmorsphere has this year affected it. 

 That potatoes do contain some proteine compound is not a new dis- 

 covery, but I do not see how it is that it should be in larger quantities 

 than usual this year, than in any preceding it. The disease unques- 

 tionably commences in the nitrogenous compounds of the potato ; 

 whether atmospheric influence caused it, is I think not yet so clear. 



Mr. Gardiner, overseer to Mr. Fleming of Baroclian, states one 

 very singular fact. He says, " Out of a small field planted with early 

 potatoes, I lifted about 5cwt. of potatos upon the 5th September. 

 These were put into a box in a house, where part of them have re- 

 mained ever since. These potatoes were sound, and perfectly free 

 from disease or taint when lifted, and are still so at this date. From 

 the same field, and under the same circumstances, I lifted the same 

 quantity of potatoes upon the 15th of September, which, after being 

 left in the house for two days, were completely tainted, and in a few- 

 days rotten and decayed. By the end of September, the whole of the 

 unlifted potatoes in this field were tainted and decaying." 



It would seem plain that in this case, the crisis in the change of the 

 healthy to the diseased tuber took place between the 5th and 15th of 

 September. 



