This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
As it appears that mildew on Grapes is still spreading through the country, I am anxious to bear testimony to the efficacy of sulphur as a preventive, and also a cure for this very troblesome disease. Last year it made its appearance here, for the first time, and, being quite unexpected, made some progress before it was perceived; after, however, a good deal of trouble and anxiety, I succeeded, principally by dusting, in saving the greater part of the crop. This year, however, as a preventive, I syringed all my vines, just previous to their expanding their bloom, twice over with a strong mixture of sulphur and water, and with the exception of two or three bunches, all my Grapes have been entirely free from its attacks during the season. The following facts are therefore, I consider, fully established: 1. That sulphur is a certain remedy for mildew after it has made its appearance, but that there is considerable trouble in its application. 2. That it is a sure preventive, with but little trouble, provided it is applied with the syringe, previous to the blooming season. 3. That little or no injury is caused to the vines by its application when mixed in water. - A. Saul, in London Gardener' Chronicle.