Medical essays : compiled from reports to the Bureau of Medicine and Surgery / by medical officers of the U.S. Navy.

  • United States. Navy Department. Bureau of Medicine and Surgery.
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Medical essays : compiled from reports to the Bureau of Medicine and Surgery / by medical officers of the U.S. Navy. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    57/384 (page 47)
    VENTILATION It is scarcely possible on board ship to supply every man with the thousand cubic feet of space for air which physiologists declare to be the minimum that can be safely assigned, except when extraordinary provisions are in operation for its renewal. Probably no single-decked vessel in the service supplies one-third of that amount. The best authorities agree that a healthy man requires a supply of twenty cubic feet of fresh air every minute. Hammond states that thirty to forty are desirable, and Professor Donkin places the minimum at three thousand cubic feet per hour. According to Martin, the constant movements going on in the atmosphere prove that the amount of change which nature has provided for healthy existence' is unlimited. The test of ventilation in a sick-ward is the comparative freshness or purity of the air. The interesting experiment of Lariboisiere appears to prove that about four thousand cubic feet per hour are required to insure this. The amount of air which passes through the lungs is variously estimated at from three hundred to four hun- dred and eighty cubic feet, four per cent, of which, at the ordi- nary rate of respiration, is carbon di-oxide, (carbonic acid gas,) that is, one hundred tinies as much as normally exists in the atmosphere, while the proportion is largely increased when the latter is moist; consequently, were there no renewal of air by ven- tilation on board ship, one day would suffice to make its atmos- phere irrespirable, since, according to Lankester, over six parts in ten thousand in a breathing atmosphere are adverse to comfort and obnoxious to health. The rapidity with which air is deterio- rated by respiration may be understood by imagining a room seven feet in size in each of its dimensions, and having nearly the