CHAPTER IIf. 
Causes of the Disease, and Remedies Stated. 
I HAVE now given, as fully as my limits would permit, the 
most important particulars concerning the history, cultivation, 
and diseases of the potatoe. I have given the various theo- 
ries that are entertained respecting the prevailing disease, 
and come now to state what I consider to be the causes of the 
malady that threatens a total destruction of the potatoe crop 
of the world, and the appropriate and simple remedies that 
will be found efficacious in staying its further progress in the 
crop of 1846, and preventing it for future time. 
The prevailing theories on the subject may be recapitulat- 
ed as follows :— 
1. Atmospheric influences. 
2. Effects of manure. 
3. Wet weather. 
4. Dry weather. 
5. Excessive heat and cold. 
6. Deterioration of the plant. 
7. Parasitical influences. 
8. Attack of the mould. 
9. Over cultivation. 
10. Over ripening. 
It must be evident even to the most superficial observer, 
that a cause must be found that is universal in its effects, be- 
eause the disease has spread throughout the world, regardless 
