The Invisible Monster.

Would-be dictator and scientist, known only as The Phantom Ruler, has developed a formula which, when sprayed on some solid object, renders that object and everything it contains invisible when exposed to rays emitted by a special lamp, also his own invention. Covered from head to toe in formula-treated cloth, he thus moves about unseen, presently with the objective of stealing enough money and formula components to render an entire army of willing followers invisible.