On One-Horse Carts. 
161 
Scotch Cart. Harvest Frame. 
XIII. — On the Prevention of Curl and Dry -Rot in Potatoes. 
By H. S. Thompson. 
To Ph. Pusey, Esq. 
My dear Sir, — The prevention of curl and dry-rot in potatoes 
is a problem the solution of which is important to every occupier 
of either farm or garden, and I therefore trust that you will not 
consider any apolojry necessary when I request the insertion, in 
the Journal of our Society, of the following paper, which contains 
the result of my observations and experiments on this subject for 
the last five years. I will first mention the result to which I have 
been led, and then enumerate the facts and state the reasoning 
which to my mind make such a conclusion inevitable. The re- 
sult, then, at which I have arrived is, that curl and dry-rot are 
caused by leaving the potatoes intended for seed in the ground 
until ripe, and that, on the other hand, these diseases may be pre- 
vented by taking up the seed-potatoes whilst the tubers are unripe, 
and the tops still green. 
1840. — In the spring of 1840 I planted 16 acres with potatoes ; 
and having, for some previous seasons, had my attention strongly 
VOL. VI. M 
