The diseases of the Pear, known by Pomologists as Leaf-Blight, Summer-Blight, Winter-Blight, Insect-Blight, and Frozen-Sap-Blight, are generally, at present, recognized under the two latter terms, though we think the leaf-blight an entirely distinct disease. There has been so much speculation upon the causes of Winter or Frozen Sap Blight, and so many remedies recommended, that we are not prepared to adopt any of the theories in explanation of it, or any nostrum as a specific.

The pear tree is a greedy absorber of fluids, and when the warm rains of September excite its absorbents, the gourmand drinks up large quantities of nutriment, and a late and rapid growth of shoots is formed. In these succulent and unripe growths, the sap is retained without that vitality of leaf which will effect its maturity and assimilation, being thin and watery, and not sufficiently matured to enable it to resist the frost, and death ensues. In the plant as well as the animal, great length of time often elapses before the poison affects the whole system and causes death. It is not unfrequent that the tree, poisoned in autumn, survives till the July following. The bark of the trunk and principal limbs exhibits black spots; and on cutting into them, the bark and wood, for some distance beneath, are found quite dead and black.

The only remedy is, to cut away at once all of the tree that is affected, cutting below the lowest spot. But few trees attacked with this disease will be of much value, even with the best treatment that can be given them. Out of forty trees, six or eight feet high, thus affected in one season, we succeeded in saving the stumps, two feet high, of only eight or ten. These trees had been brought from a distance, and planted the fall preceding the attack, and exhibited by their large, thrifty shoots, that rapid unripe growth above mentioned.