Air and moisture on shipboard : a fragment of applied physiology / by Th. J. Turner.

  • Turner, Thomas J., 1815-1901.
Date:
[1877?]
Catalogue details

Licence: Public Domain Mark

Credit: Air and moisture on shipboard : a fragment of applied physiology / by Th. J. Turner. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    Thus much briefly for the air in its constitution as affecting the health of seamen. In a much greater degree is dryness of the air an essential requirement for the health of the sailor. The amount of 0O2 being taken as the measure of aerial impurity, it has been observed by Angus Smith that its volume is increased in moist air. Lehmann says the weight of carbonic acid excreted in moist air greatly exceeds that eliminated in a dry atmosphere. It has already been observed that the effect of an increased temperature is to diminish the exhalation of CO, from the lungs. Now, the influence of moisture is so great that at high temperatures it neutralizes the effect of such tem- perature in diminishing the elimination of C02, which under such circum- stances is retained in the system. Again, as ;i general rule the expired air is saturated with moisture so that w hen the temperature of the air comes to be the same as the temperature of the body and saturated, no exhalation of aqueous vapor from the skin and lungs is possible; and there is also retained, from that fact, within the body, the excreta from these organs. It is evident that life cannot be prolonged in such an air at a temperature between 90° and 100° F. With a temperature above 80° air of excessive humidity is injurious, and yet in tropical climates such humidity is sought for by the constant wetting of the decks. The natural humidity of the air on decks at sea, or anywhere else, should never be supplemented by artificial menus to render it saturated. The writer is of the opinion from observations of his own that the aqueous vapor in the air is the solvent and carrier of the CO,,, as well as the vehicle for organic matter; and he is led to believe that in deter- mining the purity of the air by C()2 the relative humidity at the time the observation is made should always be associated. By such group- ing the value of this test is much increased, and he hazards the sugges- tion that it is the want of such connection which has led to the few dis- cordant results b.v this method of air examination. The atmospheric observations before referred to, as well as those of the writer, abundantly confirm the fact of the excessive humidity of the air on shipboard. In these observations the relative humidity of the open air on the spar-deck lias been assumed as the unavoidable as well as the standard of comparison with the relativ e humidity of the other decks. The excess over such standard, when it occurs, may be considered as the preventable humidity. It is not an unfrequenl occurrence on dry ships, and indeed it must l»e considered characteristic of them, to find the relative humidity on the inclosed decks less than that of the open air. It is well to remember in all these observations the physical law that the capacity of the air for moisture increases in a geometrical ratio with its temperature, and that for every l-'T0 F. rise in temperature the capacity of the air for moisture is doubled; and also that air is dry or moist, not in proportion to the amount of water it contains, but in pro-