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Page:Popular Science Monthly Volume 19.djvu/147

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a suitable condition to undergo development; 2. That these germs could be collected by the methods they employed, could be made to develop and multiply, and could be systematically distinguished and described; 3. That the presence of some of the germs which are commonly developed in fermenting substances was not detected in the air; 4. That the presence of germs of particular kinds was detected in air taken from the surface of the soil; 5. That the air of the sick-chamber of a typhus-hospital appeared to be singularly free from germs capable of development, a result which was attributed to effective ventilation and disinfection; 6. That the air rising from the sewer was rich in living germs; 7. That the number of observations and experiments in this their first systematic investigation is not yet sufficient to enable them to determine whether the difference in the number of germs collected from the air in different places may be taken as indicating a difference in the healthiness of the several localities—so far, they seem to give a negative result.


Forestry in India.—An address by Sir William Temple, before the Society of Arts, on "Forest Conservancy in India," calls attention to the vast destruction of forests which that country has suffered in common with other populous lands. Traditions show that the country was once covered with sylvan and other vegetation, but this dress has been removed, as the demands of man upon the surface have increased, and the most important forest-growths are now found on the mountain-ranges. The trees of India may be divided into two classes; those of the Himalayas, and those of the other mountain-ranges and the plains. The trees of both classes are magnificent specimens of growth. The Himalayan trees are allied with those of Europe and other temperate regions, and embrace, among the Coniferæ, the cedar, the Pinus longifolia, most valuable timber-trees; the cypress, the fir, the yew, and the juniper, the latter the only valuable tree that grows near Quettah. Of the other orders are the ilex, oak, and walnut, of Simla, the plane-tree of Cashmere, the maple, magnolia, laurel—here a great tree—the rhododendron, and the tree-fern, most graceful of plants. The other mountains produce the teak, the iron-hearted sal, the anjun, with its white, bright, and smooth trunk like a great marble pillar; the saj, which often grows close by the anjun, and, having a black and rough trunk, offers an effective contrast with it; the black-barked bije sal; and the white-barked, weird-looking frankincense-tree. The plains furnish the babul, or acacia, the one tree which is universal in India; the mango, the figs, among which are the banyan; and the India-rubber tree, bamboos, and palms in their varieties. The demands of the population for wood are immense, with thirty-seven million houses in British India, and one fifth as many in the native states, to be supplied, and all the implements of a people with whom iron is in comparatively little use. On account of the scarcity of wood, the people are obliged to burn manure for fuel, and thus to rob the soil of what should be returned to it, adding another to the agencies which are steadily impoverishing it. The absence of woods can not affect the total rainfall of the country, for the vapors that rise from the sea must be condensed somewhere, but it seriously affects its disposition. The clouds pass over the hot, dry plains, and precipitate their moisture upon the mountains, where they cause swift torrents to rush down into the lower country and create destruction there. The capacity of the soil to retain moisture is destroyed, and the water which would be stored in the natural forest through the dry season is lost in a sudden drought. A Forest Department has been created by the Government within the last twenty years, and gives special attention to the preservation of the remaining forests, of which the whole extent is about seventy thousand square miles. These forests are divided into the "reserves," or forests which are carefully guarded, embracing about twenty-five thousand acres, and the "protected" forests, which are imperfectly guarded and preserved. The forests of both classes have been decided to be the property of the Government. The reserves are placed directly under the care of the Forest Department. The protected forests are managed by the ordinary civil officers, under the supervision of the Forest Department. The management is directed to the