The theory and practice of military hygiene / by Edward L. Munson.

  • Edward Lyman Munson
Date:
1901
Catalogue details

Licence: Public Domain Mark

Credit: The theory and practice of military hygiene / by Edward L. Munson. Source: Wellcome Collection.

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    the recent relief expedition in China the great heat resulted in much suf¬ fering ; during the march on Pekin there were 8 deaths hi a regiment about 1,200 strong, and it is said that at one time about one-fourth of the com¬ mand was unfitted for marching from this cause. It appears to be excess of internal heat more than sunshine which re¬ sults in the phenomena known as insolation; and hence the condition may occur at night if the atmosphere, while hot, is also saturated with moist¬ ure, and heat dissipation, through evaporation of perspiration, is imperfectly carried on. Insolation rarely occurs at a high altitude and in a dry cli¬ mate, no matter how elevated the temperature. Laveran and Regnard have found that as soon as the bodily temperature exceeds 40° C. it begins to ex¬ ercise a marked influence upon the nervous system; this being greatly increased if the head is exposed to the direct solar rays. Where the condi¬ tion of insolation is actually established, the lieat-regulating centers are dis¬ organized and the temperature is extraordinarily high. Death results from the primary stimulation and subsequent paralysis of the nervous system by the heat. Exercise is a great factor hi the production of heat-stroke, and a large proportion of cases among marching troops depend almost as much on exhaustion as upon high temperature. Animals made to undergo violent exertion are more readily made to succumb than those allowed to rest quietly —and in the army it is the infantry which are most affected in this respect, cavalrymen being less liable to sunstroke than are their horses. Exercise greatly increases the production of body-heat, and Hiller found that the rectal temperature in soldiers after a hard march was that of a high fever. The mental strain and unconscious muscular rigidity which accompany mili¬ tary movements undoubtedly favor the occurrence of sunstroke. Anything which interferes with the loss of body-heat increases liability to sunstroke; this including too heavy clothing, diminution of perspiration through de¬ ficient water-supply or lowering of the processes of evaporation through excessive humidity. If the atmosphere is both hot and moist, the loss of heat by the lungs is largely impaired; hence in a marching column, carrying with it a close atmosphere saturated with moisture, it is the men in the center of the ranks who are most liable to sunstroke. The period of digestion is favorable to insolation, and it is the debilitated or intem¬ perate who are most liable to suffer in this respect. Insolation is undoubt¬ edly aided by the pressure of tight clothing, or the belts and straps by which the soldier’s load is suspended from his person. McCartie, in India, records a striking instance in the Chitral campaign of 1897, when sufficient coolies could not be obtained and part of the baggage had to be carried by native soldiers. Before the end of the march, nearly all the men in the ranks were completely exhausted and some had heat apoplexy, while their com¬ rades, carrying a much heavier weight but having assumed the light and loose native dress, were not in the least distressed. The races indigenous to hot climates possess a notable immunity as re¬ gards sunstroke; this, in the negro, being especially great and furnishing an additional argument for the organization of native forces for tropical service. Some of the symptoms of insolation are said by Notter to be caused by the reflected rays of the sun through the orbit, when the optic nerve is exposed to direct rays of light. In the British service, neutral- tinted glasses are frequently worn as a protection to the eyes, and the