1 other embodiments of the recognition elements described above can also be correspondingly attached instead of the magnets 2 fig7 including fig7 a c shows three exemplary embodiments for attaching a recognition element 2 e g a magnet 2 in the wall 1 a of an ampoule 1 wherein the magnet 2 is formed cylindrical and is shown as a circular cross section in the embodiment shown in fig7 a magnets 2 can be inserted in a cylindrical hollow space which exhibits a certain tolerance in their dimensions wherein the magnets 2 can be either freely mounted in the corresponding hollow spaces or fixed using a suitable adhesive fig7 b and 7c show a magnet being fastened by clamping it in the ampoule wall 1 a it is advantageous here if the ampoule wall 1 a consists of an elastic material such as for example a suitable plastic fig8 shows an alternative embodiment for fastening a magnet 2 in an ampoule wall 1 a wherein the magnet 2 is formed parallelepipedal and can be deformed if such a parallelepipedal magnet 2 is deformed at its edges and inserted into a cylindrical hollow space of the ampoule wall 1 a then the magnet 2 can be supported laterally in the ampoule wall 1 a by its edges and thus be held fixedly in the ampoule wall 1 a fig9 including fig9 a and b shows another embodiment for forming a magnet 2 in an ampoule wall 1 a wherein a plastic emulsion comprising magnetic or magnetizable materials is inserted into.