A new system of the spleen, vapours, and hypochondriack, melancholy; wherein all decays of the nerves and lownesses of the spirits, are mechanically accounted for. to which subjoin'd a discourse upon the nature, causa, and cure of melancholy, madness and lunacy; with a particular dissertation on the origine of the passions... to which is prefix'd a philosophical essay concerning the principles of thought, sensation and reflexion...