Page:Popular Science Monthly Volume 43.djvu/117

Rh practicable to run milk into the machine and take from it butter, thus avoiding the handling of the cream at all.

The cream separator enables the dairyman to dispense with numerous utensils ordinarily used in setting milk, and in hot climates is invaluable, as it saves much of the great expense of ice. Centrifugal cream is unexcelled. In a comparatively few years these valuable dairy utensils will be commonly found in use on the dairy farms of the country.

Never before in the history of man have agricultural plants apparently suffered so greatly from parasitic vegetable growths and injurious insects. The conditions of growth have been made so much more intense for many plants that they have in consequence, in certain directions, thus made themselves more vulnerable to the attacks of parasites and insects. Some insects have been deprived of their normal food in a large degree, and have sought sustenance in agricultural crops. The destruction of these ravagers meant the saving of valuable crops; consequently much important experimental work has been accomplished with fungicides and insecticides.

For two score of years the grape rot has caused immense damage in the vineyards of the Eastern United States. A small plant, so minute as to require a high-power microscope to bring it to view, feeds upon the juices of the tender leaves and berries of the grape, blasting and ruining the fruit. The parasite matures and ripens its spores or seeds in vast quantities, and these are blown over adjacent vines and the disease more widely scattered.

Within a few years the botanists of both Europe and America began to devise means to prevent this malady. After long experimental work with fungicides and spraying machines, a mixture of sulphate of copper (six pounds), unslaked lime (four pounds), and water (forty-five gallons), termed Bordeaux mixture, was adopted, which, when sprayed on the vines several times during the growing season before the grapes became ripe, completely prevented the ravages of the rot. Applications are made after the buds have started, and four or five times later on. Experiments, generally conducted by scientists with the Bordeaux mixture, have shown it to be most excellent for preventing numerous diseases of plants caused by parasitic growth. The method is cheap, and small hand machines, or large pump tanks with spraying attachments and drawn by teams, are made, by which one can rapidly and effectively spray large areas at comparatively slight expense. So extensive is the use of Bordeaux mixture becoming that all along the Hudson and in other grape regions, in