But the dark powers which the soldier invoked to his aid were treacherous. They did not protect against everything; it was, to say the least, very unsatisfactory that they did not preserve from the hand of the executioner: Zimmermann relates many cases in which the far-reaching hopes of an invulnerable person and his adherents were disappointed at the place of execution. Certain portions of the body, the neck, and the back between the shoulders, the armpits, and the under part of the knee, were considered not hard or invulnerable. The body also was only charmed against the common metals of lead or iron. The simplest weapons of peasants, a wooden club, bullets of more precious metals, and sometimes inherited silver could kill the invulnerable. Thus an Austrian governor of Greifswald, on whom the Swedes had fired more than twenty balls, could only be shot by the inherited silver button that a soldier carried in his pocket. Thus too a witch in Schleswig was changed into a were-wolf, and shot by inherited silver.[19] The magic also could be broken by other mixtures, by cast balls, and by magically consecrated weapons. Rye bread which had been leavened and baked on Easter night, was rubbed crosswise over the edge of the steel, and signs were indelibly impressed on blades and barrels: it was known how to cast balls which killed without injuring the skin, others which must draw blood, and some which broke every invulnerability; these were prepared by mixtures of pulverized grains of corn, antimony, and thunder-stones, and cooled in poison. But these arts were considered supernatural and dangerous. Besides these they tried "natural" devices which might be resorted to with advantage, even by an honourable soldier. They imagined they could prepare gunpowder with a mixture of pounded dogs' bones, which would make no report. Powder was also prepared by which the person shot was only stunned for hours; other powder that did not explode, even when glowing steel was inserted. By a mixture of borax and quicksilver they produced a mining powder by which the enemy's pieces were blown up, in case there was not time to spike them. They sought after the secret of giving a man double strength without magic. There was a peculiar and also very old kind of magic, which spell-bound the enemy by mystic sentences, which were recited in moments of danger. The adept could fix whole troops of horsemen and infantry: in the same way, by other sentences, they could dissolve the spell. There was still another kind of sorcery; horsemen were made to appear on the field of battle, that is to say, when support was required in imminent danger, deceptive appearance was produced, as if soldiers were approaching in the distance. Both these conjurations are relics of the heathen occult sciences, the echoes of which may still be discovered in manifold tales and traditions, even up to the present day.