Whale-oil soap dissolved in water and used as a spray is an effective remedy for the San Jose scale. Kerosene emulsion is used to kill the insects which suck the juices of plants and trees. It is made by mixing a half-pound of hard soap with one gallon of hot water and stirring into it, so as to mix thoroughly, two gallons of kerosene oil. This may be kept on hand for use, and is mixed with ten parts of water to one of the emulsion. For use in large orchards force-pumps operated by compressed air and drawn by two horses are used. The spraying should be done as soon as the blossoms drop, and many orchards are sprayed three times in a season, but the work should never be done while the trees are in blossom. Vegetables should be sprayed many times through the season. A careful study of these methods of control, adapted to the various plants and the insects which prey on them, with the natural enemies of insects encouraged and protected, would go far to prevent the wide-spread and serious damage now affecting our crops, our vegetables, our orchards, and our forests. REFERENCES Circulars of the Bureau of Entomology. Dept. of Agriculture. List furnished on application. Annual Loss Occasioned by Destructive Insects. Yearbook 1904.[C] [Footnote C: Some of the Yearbooks of the Dept. of Agriculture contain very instructive reports on Insects and on Birds. Reprints on various subjects have been made from them which are available in pamphlet form, or the entire Yearbook may be had in many cases.] Value of Insect Parasitism to the American Farmer. Yearbook 1907. House Flies. Dept. of Agriculture. Bulletin 71. The Grasshopper Problem. Bulletin 84. The Boll-Weevil Problem. Bulletin 344. The Most Important Step in the Control of the Boll-Weevil. Bulletin 95. The San Jose Scale. Yearbook 1902. The Plum-Curculio. Bulletin 73. The Apple Codling-Moth. Bulletin 41. Price 20c. The Gipsy Moth and How to Control It. Bulletin 275. The Brown-tail Moth and How to Control It. Bulletin 264. The Spring Grain Aphis or Green-Bug. Bulletin 93. The Army-Worm. Bulletin 4. The Hessian Fly. Bulletin 70. The Chinch-Bug. Bulletin 17. The Principal Household Insects of the U. S. Bulletin 4. Insects Affecting Domestic Animals. Bulletin 5. CHAPTER XI BIRDS Birds give us pleasure in three ways: by their beauty, by their song and by their usefulness in destroying animals, insects or plants which are harmful to man. But although they are among man's best friends they have been greatly misunderstood, so that to the many natural enemies that are constantly preying on birds, we must add the warfare that man himself wages on them, and the cutting down of their forest homes. This work of bird destruction has gone on until all the best species are greatly reduced in numbers and some species have been almost entirely driven out.