The atmosphere in relation to human life and health.

  • Russell, Francis Albert Rollo, 1849-1914.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: The atmosphere in relation to human life and health. 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.

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    metallic and other elements of the earth, forms also, in union with hydrogen, the great body of water which covers three-fourths of the terrestrial surface. Water consists of two volumes of hydrogen and one volume of oxygen chemically combined. Stated by weight, out of nine parts of water eight are oxygen. But water, as we know it, always contains other matter, and chiefly atmospheric air, which is dissolved in it, and to a considerable extent changes its character. Eor the serv- ice of man, water, deprived of air, would have lost several important characteristics. Oxygen is dissolved in water to the extent of 2.99 volumes to 100 of water at 15° C, an amount sufficient to support the existence of fishes and hosts of other aquatic creatures, and to oxidize and render innocuous some of the common imfturities which result from animal and vegetable processes and decay. Probably its jjower when dissolved in the liquid is greater than in the atmosphere, and it must be compressed into a smaller space. Fresh charcoal absorbs eighteen times its volume of oxygen, and a much larger bulk of organic vajjors, especially ammonia; in this condensed state the oxygen acts so power- fully as to unite with hydrogen to form water vapor, and with sulphur to form sulphur dioxide. We may thus assume that water, as we use it and drink it, has important effects upon the body which would not take place if robbed of its contained oxygen. As an instance of the value of the air contained in water for many domestic purposes, its assistance in the making of tea may be mentioned; if the air be allowed to boil out of the water the beverage is spoiled. Eecent observation, however, shows that oxygen is not altogether removed from good water by the process of boiling.' Oxygen has a very strong chemical attraction for the elements; only one is known with which it does not combine. Hence, to burn in common language means combination with oxygen, and most sub- stances in the crust of the earth are already burnt, or combined with oxygen. In its ordinary form it has no color, taste, or smell, according to most observers, but recently a faint blue color has been detected as belonging to it, when seen in sufficient quantity. It has a small refracting influence on light, and exhibits a magnetic proj)erty, espe- cially strong in the liquid form, to which it has recently been driven by intense cold and pressure. The degree of cold required was — 140° 0. under a pressure of 320 atmospheres. The x>roportion, by weight, of oxygen in the air has l)een determined by Leduc as 23.58 per cent.^ The volume of oxygen in the air in different localities and conditions has been tested by various observers. On the western seashore of Scotland the percentage was found to be 20.991; on the tops of hills, 20.98; in a sitting room (close), 20.89; at the backs of houses, 20.70j at the bottom of shafts in mines, 20.44. 1 See Comptcs Rendus, 1890. M. Muller. 'Coniptes Rendus, 1890. A. Leduc.