We have now to consider the destructive influence which marches have upon an army. It is so great that it may be regarded as an active principle of destruction, just as much as the combat.
One single moderate march does not wear down the instrument, but a succession of even moderate marches is certain to tell upon it, and a succession of severe ones will, of course, do so much sooner.
At the actual scene of war, want of food and shelter, bad broken-up roads, and the necessity of being in a perpetual state of readiness for battle, are causes of an excessive strain upon our means, by which men, cattle, carriages of every description as well as clothing are ruined.
It is commonly said that a long rest does not suit the physical health of an army; that at such a time there is more sickness than during moderate activity. No doubt sickness will and does occur if soldiers are packed too close in confined quarters; but the same thing would occur if these were quarters taken up on the march, and the want of air and exercise can never be the cause of such sicknesses, as it is so easy to give the soldier both by means of his exercises.
Only think for a moment, when the organism of a human being is in a disordered and fainting state, what a difference it must make to him whether he falls sick in a house or is seized in the middle of a high road, up to his knees in mud, under torrents of rain, and loaded with a knapsack on his back; even if he is in a camp he can soon be sent to the next village, and will not be entirely without medical assistance, whilst on a march he must be for hours without any assistance, and then be made