Mildew is a parasitical fungus, often seen on greenhouse and other plants, and is quickly destructive to their health. But as with all other plant troubles, it is best to prevent rather than cure. Care should be taken, particularly where roses or grape vines are grown under glass, as both of these are especially liable to be attacked, to avoid a rapid change of temperature, or a long exposure to sudden chill by draughts in ventilating. As soon as spots of grayish-white appear on the leaves of roses or grapevines, either out-doors or under glass, it is certain that mildew is present, but if it has not been neglected too long, the following preparation will usually be found a prompt remedy. Take three pounds each of flowers of sulphur and quick-lime, put together and slake the lime, and add six gallons of water; boil all together until it is reduced to two gallons, allow the liquid to settle until it gets clear, then bottle for use. One gill only of this is to be mixed in five gallons of water, and syringed over the plants in the evening, taking care not to use it on the fruit when ripe, as it would communicate a taste and smell which would render it useless. Applied in this weak state, it does not injure the leaves, and yet has the power to destroy the low form of vegetable growth, which we call mildew. We apply it just as we do tobacco, once or twice a week, as a preventive, and we rarely have a speck of mildew.