Abstract
The article deals with the priority of Mendeleev in arranging the elements and formulating a general conclusion - the periodic law. The periodic system of elements was a product of centuries old attempts to organize material, inorganic world.
Not only Mendeleev but many scientists before and after publication of the table failed in their search for new elements, what has resulted in numerous erroneous discoveries. They belong inherently to the history; a few examples are given in this contribution.