While still in the cradle he had been attacked by smallpox of the most malignant type.  The virus having spread through all his body, laid bare his ribs, and almost ate away his skull.  For several months he lay between life and death; but life at last gained the upper hand.  He remained weak and sickly, however, up to his seventh year, at which time a brain fever attacked him; and again put his life in danger.  As a compensation, however, this fever, when it left him, seemed to carry away with it all vestiges of his former illness.  From that moment his health and strength came into existence; but during these two long illnesses his education had remained very backward, and it was not until the age of eight that he could begin his elementary studies; moreover, his physical sufferings having retarded his intellectual development, he needed to work twice as hard as others to reach the same result.

Seeing the efforts that young Sand made, even while still quite a child, to conquer the defects of his organisation, Professor Salfranck, a learned and distinguished man, rector of the Hof gymnasium [college], conceived such an affection for him, that when, at a later time, he was appointed director of the gymnasium at Ratisbon, he could not part from his pupil, and took him with him.  In this town, and at the age of eleven years, he gave the first proof of his courage and humanity.  One day, when he was walking with some young friends, he heard cries for help, and ran in that direction:  a little boy, eight or nine years old, had just fallen into a pond.  Sand immediately, without regarding his best clothes, of which, however, he was very proud, sprang into the water, and, after unheard-of efforts for a child of his age, succeeded in bringing the drowning boy to land.

At the age of twelve or thirteen, Sand, who had become more active, skilful, and determined than many of his elders, often amused himself by giving battle to the lads of the town and of the neighbouring villages.  The theatre of these childish conflicts, which in their pale innocence reflected the great battles that were at that time steeping Germany in blood, was generally a plain extending from the town of Wonsiedel to the mountain of St. Catherine, which had ruins at its top, and amid the ruins a tower in excellent preservation.  Sand, who was one of the most eager fighters, seeing that his side had several times been defeated on account of its numerical inferiority, resolved, in order to make up for this drawback, to fortify the tower of St. Catherine, and to retire into it at the next battle if its issue proved unfavourable to him.  He communicated this plan to his companions, who received it with enthusiasm.  A week was spent, accordingly, in collecting all possible weapons of defence in the tower and in repairing its doors and stairs.  These preparations were made so secretly that the army of the enemy had no knowledge of them.