A supplement to the Revolution in mind & practice of the human race : shewing the necessity for, and the advantages of this universal change : also, a copy of the original memorial (in English, French, and German) which was presented to the sovereigns assembled in congress at Aix-la Chapelle in 1818 ... from the author of this work, shewing the correctness of his anticipations, as proved by subsequent events : to which is added, a discourse delivered to the socialists of London on the 25th of October, 1849