Page:Popular Science Monthly Volume 78.djvu/485

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475
CONTROL OF PLANT DISEASES

years 1846 and 1864, notwithstanding the fact that the first sulphur treatment for powdery mildew was recommended in 1821 and the first seed treatment for smuts was discussed in 1807.

PSM V78 D485 Advance knowledge of the spread of animal diseases 1.png

Table II. Showing Advance in Knowledge regarding some of the Chief Diseases of Domestic Animals. The broken upper line indicates vague or indefinite knowledge; the solid line definite knowledge. The lower broken line indicates partial but unsatisfactory knowledge concerning treatment; the solid line the possession of facts sufficient for satisfactory treatment.

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{sc|Table III. Showing Advance in Knowledge regarding some of the Chief Human Diseases.}} The broken upper line indicates vague or indefinite knowledge; the solid line definite knowledge. The lower broken line indicates partial but unsatisfactory knowledge concerning treatment; the solid line the possession of facts sufficient for satisfactory treatment.