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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![THE ATMOSPHERE IIT RELATION TO HUMAK LIFE AND HEALTH. By Francis Albert Rollo Russell,* Vice-President of the Boyal Meteorological Society, Fellow of the Sanitary Institute of Great Britain, Member of the Royal Institution of Great Britain. [Memoir Hubmitted in the Hodgkins Fund Prize competition of the Smitlisoniaa Institution, and awarded honorable ruentioa with a silver medal.] Part I.—Constitution and Conditions of the Air. The atmosphere has been compared to a great ocean, at the bottom of which we live. But the comparison gives do idea of the magnitude of this ocean, without definite bounds, and varying incessantly in den- sity and other important qualities from depth to height and from place to place. Uninterrupted by emergent continents and islands, the atmosphere freely spreads high above all mountains and flows ever in mighty cur- rents at levels beyond the most elevated regions of the solid earth. What is the composition of this encompassing fluid, and what its char- acter? The work of the present century has gathered in a rich store of knowledge to answer the inquiry. The atmosphere consists in the main of two gases, oxygen and nitro- gen, and these are intimately mixed in the proportion of about 20.9 of oxygen to 79.1 of nitrogen by volume, and 23.1 of oxygen to 76.9 of nitrogen by weight. ^ These gases, which are each of them chemical ele- ments, are not chemically combined with one another, but only mixed; each preserves its qualities, modified only by solution in the other. Gases have the property of diffusing among each other so comj^letely, that no portion which could be conveniently taken, however small, would fail to represent the two gases in a proportion corresponding with that which they maintain in the whole atmosphere. Another valuable constituent of the atmosphere, though varying greatly in amount at different times and places, is of no less impor- 'Author of Lonilon Fogs, Epidemics, Plagues, and Fevers; their Causes and Prevention, The Spread of Influenza, Observations on Dew and Frosts, etc. -M. Leduc gives the weights as follows: Oxygen, 23.58; nitrogen, 76.42. Dumas and Boussingault give the density of nitrogen as 0.09725. (Comptes Eendus, 1890.)](https://iiif.wellcomecollection.org/image/b21208724_0015.jp2/full/800%2C/0/default.jpg)
