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ces, in variable proportion. It has been ascertained by chemical analysis, that in order to be fertile, a. ‘ oil must contain certain quantities of these mineral, saline and vegetable substances, some of which are ound in the ash of plants. It is not only necessary that those substances should be present, but they must exist in certain quantities, and it is their proper adjustment that renders the soil most productive. It hould be the principal object of the farmer to study the soil he cultivates, the kind ot'crop most favorable, and the means necessary for its improvement, che- ' istry, mineralogy and geology being brought to his aid.

The object of chemical analysis is to obtain an ‘aciurate knowledge of the constituents of the best inds of soil for different crops, and to compare them with the elements of soils that are unproductive. By such a comparison, the substances that are deﬁcient .in sterile earth, are readily discovered and may be supplied by artiﬁcial means. It might be expected that from a course so simple and plain, knowledge could be gained, whereby the most barren waste could immediately be rendered fertile. It is true that he iapid advances of geology and chemistry, have brought this desirable end in view, yet nature some- imes seems to mock the efforts of art, and science 5 unable to control the physical world. The electric urrents set in motion by the decomposition of mines 'al matter, are but imperfectly understood, nor has heir inﬂuence upon vegetation been brought within he control ofthe agriculturist. The diﬁ'erences and icissitudes of climate, the variations of the atmos- here, heat, dryness, moisture, 850., all exercise in- uences over the growth of plants, but their causes re beyond the reach of art or industry.

The analysis of soils and minerals is an art that re- uires sound chemical knowledge and skill in manipu- ation. Time and patient investigation are necessary obtain correct results. Heretot‘ore this branch of ,‘hemistry has been undervalued by agricultural bo-

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