Having obtained the permission of the landgrave to visit Berlin, he sent the keys of his cabinet back to the authorities at Cassel--and disappeared.

His thefts, to the amount of two thousand rixdollars, were promptly discovered, and advertisements were issued for the arrest of the Councillor Raspe, described without suspicion of flattery as a long-faced man, with small eyes, crooked nose, red hair under a stumpy periwig, and a jerky gait.

The necessities that prompted him to commit a felony are possibly indicated by the addition that he usually appeared in a scarlet dress embroidered with gold, but sometimes in black, blue, or grey clothes.

He was seized when he had got no farther than Klausthal, in the Hartz mountains, but he lost no time in escaping from the clutches of the police, and made his way to England.
He never again set foot on the continent.
He was already an excellent English scholar, so that when he reached London it was not unnatural that he should look to authorship for support.

Without loss of time, he published in London in 1776 a volume on some German Volcanoes and their productions; in 1777 he translated the then highly esteemed mineralogical travels of Ferber in Italy and Hungary.