Though Sand was not accustomed to great bodily fatigues, he endured those of the campaign with surprising strength, refusing all the alleviations that his superiors tried to offer him; for he would allow no one to outdo him in the trouble that he took for the good of the country. On the march he invariably shared: anything that he possessed fraternally with his comrades, helping those who were weaker than himself to carry their burdens, and, at once priest and soldier, sustaining them by his words when he was powerless to do anything more.
On the 18th of June, at eight o’clock in the evening, he arrived upon the field of battle at Waterloo, On the 14th of July he entered Paris.
On the 18th of December, 1815, Karl Sand and his brother were back at Wonsiedel, to the great joy of their family. He spent the Christmas holidays and the end of the year with them, but his ardour for his new vacation did not allow him to remain longer, and an the 7th of January he reached Erlangen. Then, to make up for lost time, he resolved to subject his day to fixed and uniform rules, and to write down every evening what he had done since the morning. It is by the help of this journal that we are able to follow the young enthusiast, not only in all the actions of his life, but also in all the thoughts of his mind and all the hesitations of his conscience. In it we find his whole self, simple to naivete, enthusiastic to madness, gentle even to weakness towards others, severe even to asceticism towards himself. One of his great griefs was the expense that his education occasioned to his parents, and every useless and costly pleasure left a remorse in his heart. Thus, on the 9th of February 1816, he wrote:—
“I meant to go and visit my parents. Accordingly I went to the ‘Commers-haus’, and there I was much amused. N. and T. began upon me with the everlasting jokes about Wonsiedel; that went on until eleven o’clock. But afterwards N. and T. began to torment me to go to the wine-shop; I refused as long as I could. But as, at last, they seemed to think that it was from contempt of them that I would not go and drink a glass of Rhine wine with them, I did not dare resist longer. Unfortunately, they did not stop at Braunberger; and while my glass was still half full, N. ordered a bottle of champagne. When the first had disappeared, T. ordered a second; then, even before this second battle was drunk, both of them ordered a third in my name and in spite of me. I returned home quite giddy, and threw myself on the sofa, where I slept for about an hour, and only went to bed afterwards.
“Thus passed this shameful day, in which I have not thought enough of my kind and worthy parents, who are leading a poor and hard life, and in which I suffered myself to be led away by the example of people who have money into spending four florins—an expenditure which was useless, and which would have kept the whole family for two days. Pardon me, my God, pardon me, I beseech Thee, and receive the vow that I make never to fall into the same fault again. In future I will live even more abstemiously than I usually do, so as to repair the fatal traces in my poor cash-box of my extravagance, and not to be obliged to ask money of my mother before the day when she thinks of sending me some herself.”