
          195

Concludes that something prostrates the vital power in
the diseased leaves and fruit.  Does not think it is a poison
derived from the soil (8) nor from the atmosphere (12). "It
cannot, I think, be owing to particular sorts of peaches having
been propagated for a long period , and beyond their natural 
term of existence (13 and 17).  It may be remarked that
the early Ann mentioned in Sec. 17 is one of our oldest sorts."

"I think the disease cannot be ascribed to defective
cultivation, to injudicious pruning, of injury to the roots
of trees; for there was abundance of such cultivation, pruning
and injury to roots before the 'yellows' made its appearance.
The peach worm cannot, I think, be charged justly
with the mischief; for thousands of trees have had the yellows
which were untouched by the borer."  He hazards a conjecture 
that the disease may be due to 'some new, unknown, shy
insect."  Thinks that it has been gradually extending from 
place to place over the country and poisoning our peach trees.

He knows no means of warding off or curing the yellows.
Mentions ashes, salt, saltpeter, urine, etc. "Some of them
have seemed to promote for a time the growth of the trees,
and to give a deeper green to their leaves; but none, that I 
have ever observed have at all checked the progress of the
yellows."
        