Fruit cultivators are gradually becoming aware that mildew in some one of its various developments, is the most prevalent and insidious enemy with which they have to contend. Exotic grapes are so subject to it, that their culture in open air has been abandoned, and even in glazed houses considerable attention is required to prevent its attacks. The native grapes are not exempt, and in some seasons the foliage is so extensively injured as to materially reduce the value of the crop. The gooseberry also suffers, and even the hawthorn, lilacs, tulip trees, and other ornamental plants show the extensive range of the parasitic affection. There is a growing conviction that the cracking of the pear is the result also of a species of mildew, ana it may be found that applications of sulphur-water will be a surer prevention of this disease, than those special manures which have been recommended, and which have not been found to remedy the evil, or give indications of a curative process.

The peculiar atmospherical conditions tending to the increase of mildew, are not particularly well understood. I have frequently repeated my conviction that the peculiar mildew seen on the foreign grape under glass, on the gooseberry, lilac, etc, is induced by atmospheric aridity. This mildew develops in the form of a mouldiness on the upper surface of the foliage, and frequently extends and envelops young growing shoots, in which case the bark seems to contract and crack into lengthened openings. Here can be traced a close resemblance to the cracking of the pear, going far to prove that it has the same origin. In sheltered city yards, where drying winds are arrested in their sweeping progress, and where a quiet and more humid atmosphere prevails, the foreign grape will frequently attain to a fair perfection. So also the White Doyenne pear is annually produced in its greatest perfection on trees similarly located, while in open exposures a few miles distant, a fair specimen cannot be procured. No reason that has ever been brought forward on the probable cause of pear-cracking is so philosophical, or so much in accordance with recorded facts, as that which connects it with mildew. The mildew seen on the native grape, is apparently a different fungus from the above.

Here the "under " side of the leaf is attacked, destroying the vitality of the tissue, which is then tender, and is speedily scorched by sun, and the leaves decay and wither. When this occurs during the ripening of the crop, the sudden loss of foliage prevents it from maturing, and hence many bunches will show one-half of the fruit black and the other green. This apparent scorching is most noticeable during the months of August and September, when heavy night dews are succeeded by hot sun, or after a few dull or rainy days.

The whole subject is one demanding the general attention of cultivators; and in connection with practical observation, we would recommend the careful perusal of the valuable reports on this and kindred subjects, made from time to time during the last ten years, by the Rev. C. E. Goodrich, Utica, N. Y.

Mildew #1

Paint your vines, stems, and branches, and the entire of your vinery and wall, with a mixture of lime, flowers of sulphur, soft-soap, and water. So soon as the vine buds begin to swell in the spring, sprinkle flowers of sulphur over the borders. During their growth in summer, though no mildew is perceptible, fill the house occasionally with fumes of sulphur, by placing some on plates of iron kept hot by boiling water. You can easily do this by many simple modes.