Climatology and mineral waters of the United States, by A. N. Bell.

  • Bell, A. N. (Agrippa Nelson), 1820-1911.
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: Climatology and mineral waters of the United States, by A. N. Bell. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    110/404 (page 96)
    OHAPTEE XII. FORESTS. FUNCTIONS OF PLANTS IN DRYING THE SOIL—FOREST AIR ESSENTIALLY MOIST—SPECIAL QUALITIES OF PINE FORESTS—CONSERVATIVE IN- FLUENCE OF FORESTS IN COLD CLIMATES—EFFECTS OF FORESTS ON TEMPERATURE—RELATIONS OF ELECTRICITY AND OZONE TO FORESTS —THE EUCALYPTUS, ITS HISTORY, CULTIVATION, AND PROPERTIES. The influence of forests in producing and modifying the effects of a humid state of the atmosphere is, in some respects, comparable with the sea-coast and the ocean. The great Dismal Swamps of Virginia and the Carolinas, for example, are known to be healthy in the interior, even for the white man, while on their borders, or in portions where the trees are felled, they are like the sea-coast—commonly insalubrious. The same conditions obtain in the Mexican Gulf region and on the west coast of Africa. On the borders of the great forests, or wherever they are interspersed with sandy plains or sparse of trees from other causes, fevers prevail; while in the denser regions, and especially where the forest consists of spike-leaved trees, fevers are ordinarily absent. In- deed, the common belief that intervening trees even often afford protec- tion against malarious marshes is founded on observations sufficiently well verified to be accepted as a general truth. And, as truly remarked by Becquerel, more than thirty years ago, Humid air charged with mias- mata, is deprived of them in passing through a forest.-1 Yet forests are in themselves store-houses of moisture everywhere. That forests are commonly salubrious is probably due to the joint functions of the trees in draining the soil, distilling the moisture, emission of aromatic vapors, particularly of the pitch-pine and eucalyp- tus, and absorbing the emanations of vegetable putrefaction. And here it may be remarked that while moisture is an indispensable condition of forests, they do not have, as is popularly supposed, much, if indeed any, influence over the rainfall. Those who hold that they do, mistake effect for cause—the rain produces the forest, and not the forest the rain. Soil drainage is naturally accomplished in forests by the processes of 1 Becquerel: Des Climats et de l'lnfluence qu exercent les sols boises et non •boises.