Esdubleveium

Esdubleveium (colloquially called "esew gas") is a chemical element with very addictive properties.

Chemical properties
Esdubleveium is a relatively dense gas with a very high atomic number. It has a greenish shade. The only known stable isotopes are Z=420, A=669 and Z=420, A=842.

Addictive properties
When consumed by breathers of oxygen, hydrogen, nitrogen and other light gases, Esdubleveium creates multiple copies of atoms to multiply the gas. It facilitates breathing to such an extent, that when the effect ends, the inhaler requires more of this, which leads to mental illnesses and sometimes suicide.

Legality
Esdubleveium is illegal in a wide array of verses. Some councils refuse to treat intentional Esdubleveium takers with proper healthcare, instead sending them to cells where they cannot pose any threat.