The Potatoe Plague. 77 
extra supply of food; potatoes, therefore, grown on such soil, 
will be in a growing state when those on old-going Jand will 
be quite ripe, and if harvested together the former will be 
unripe and make good sets. It is very probable, however, 
the more abundant supply of all the elements of nutrition to 
be found in fresh soil may have a considerable effect, and 
concur with the under-ripening of the seed in producing a 
healthy and vigorous plant. 
