Hydrogen was the gas flavoured by the Nazzies for lifting their airships. Not, as many believe, because it is the lightest element and has the greatest lifting power. No, it was because Hitler's vegetarian diet meant he was incredibly and toxically flatulent, and was able to provide an inexhaustible supply of the gas.
Sadly, the Nazzies got carried away with the success of their airship programme, and gleefully accepted sponsorship from Zippo without fully considering the possible consequences.