Swimming, considered with regard to the movements that it requires, is
useful in promoting great muscular strength; but the good effects are
not solely the result of the exercise that the muscles receive, but
partly of the medium in which the body is moved. Both the considerable
increase of general force, and the tranquillizing of the nervous system
produced by swimming, arise chiefly from this, that the movements, in
consequence of the cold and dense medium in which they take place,
occasion no loss.[8] It is easy to conceive of what utility swimming
must be, where the very high state of the atmospheric temperature
requires inactivity in consequence of the excessive loss caused by the
slightest movement. It then becomes an exceedingly valuable resource,
the only one, indeed, by which muscular weakness can be remedied, and
the energy of the vital functions maintained. We must therefore regard
swimming as one of the most beneficial exercises that can be taken in
summer.
[8] The expression “loss” here, is used as the result produced by
increased evaporation from the pores, consequent upon violent bodily
exertion.
[Illustration: _Plate XX_
_Page 83._