The Potatoe Plague. 103 



the crops there are beginning to fail, owing to the practice of 

 planting year after year on the same soil. They do not rot 

 but get smaller in size. An alkali of a very deleterious 

 nature ( Solaniri) is found in the sprouts of potatoes which 

 shoot in cellars, while not a trace of it is found in sprouts 

 grown in soil. How far this tends to injure the tuber is not 

 ascertained, but it is highly probable that such a tendency is 

 induced. It is not probable that the degeneration of the 

 tuber in one year immediately induced rot, by neglect, 

 transformations have been going on for years, which have 

 ultimately led to it. Experiments might easily be instituted 

 to show how far shoots produced in cellars affect the crop, 

 and it is certainly worth ascertaining. 



OVER-CULTIVATION. What has been said on this sub- 

 ject in the foregoing pages should be re-perused with care 

 and especial attention, as this is one of the main causes that 

 has produced the great evil. It may be asked, indeed it will 

 be asked, " If rot arises from this, and the other causes you 

 have named, why has not the evil appeared before, and why 

 is it so universal now ? " I answer, that while the crop was 

 produced by manures that are not highly stimulating, on land 

 that did not contain a superabundance of nutritive matter, 

 and w r hile the quantity produced per acre was moderate, the 

 disease was not developed ; that in the interior, away from 

 cities and large towns, there was no trouble with the crop for 

 a great number of years ; that in the immediate vicinity of 

 cities where manure is abundant, and the land highly fed, the 

 disease made its appearance in a very early stage of the cul- 

 tivation of the crop, and its progress was only stayed by 

 yearly importations of seed from back countries ; that the 

 disease has been steadily increasing for years, and it is not 

 a new disease, but has progressively increased wherever the 

 crop is cultivated ; that the manner of saving and preparing 

 seed, growing crops, manuring and cultivation is, and has 



