CHAPTER IV. 
An Account of Diseases which have previously affected the 
Potatoe, and the Remedies that have been found efficacious. 
In finding materials for this chapter I must necessarily 
confine my attention principally to English publications, as 
English writers on agriculture have noted and marked the 
nature, effects, and cure of the various diseases which have 
affected this root, with more exactness and precision than 
have characterized American writers on this subject. 
The potatoe is subject to disease at a very early period of 
its existence, not merely after it has developed its leaves and 
stems, but before the germ has risen from the sets. The 
disease which affects the plant is called the curl, from the 
curled or crumpled appearance which the leaves assume 
when under the influence of the disease. What the imme- 
diate cause of the disease is, it is very difficult to say; but 
the puny stems and stinted leaves indicate weakness in the 
constitution of the plant, and, like weak animals affected with 
constitutional disease, the small tubers produced by curled 
potatoes, when planted, propagate the disease in the future 
crop. The curl is so well known by its appearance, and the 
curled plant so generally shunned, as seed, that the disease is 
never willingly propagated by the cultivator; still there are 
circumstances in the management of the tubers which induced 
the disegse therein, The experiments of Mr. T. Dickson 
