How to Cite
It is a great honour for me to write these few lines of preface to the special issues of Substantia dedicated to the 150th anniversary of the Periodic Table by Dmitrij Mendeleev. In 2019 there are other important anniversaries besides that of the periodic table. One of these is the centenary of Primo Levi’s birth. I believe these two anniversaries are strictly related, in fact The Periodic Table by Levi has been considered by the Royal Institution of Great Britain as the “best book of science ever written”.