[511] Dalton. John Dalton was an English chemist who, about the beginning of the nineteenth century, perfected the atomic theory, that is, the theory that all chemical combinations take place in certain ways between the atoms, or ultimate particles, of bodies. [512] Davy. (See note 69.) [513] Black. Joseph Black, a Scotch chemist who made valuable discoveries about latent heat and carbon dioxide, or carbonic acid gas. [514] The astronomers said, etc. Beginning with this passage, several pages of this essay was published in 1844, under the title of Tantalus, in the next to the last number of The Dial, which Emerson edited. [515] Centrifugal, centripetal. Define these words. [516] Stoics. See "Stoicism," 331. [517] Luther. (See note 188.) [518] Jacob Behmen. A German mystic of the sixteenth century; his name is usually written Boehme. [519] George Fox. (See note 202.) [520] James Naylor. An English religious enthusiast of the seventeenth century; he was first a Puritan and later a Quaker. [521] Operose. Laborious. [522] Outskirt and far-off reflection, etc. Compare with this passage Emerson's poem, The Forerunners. [523] [OE]dipus. In Greek mythology, the King of Thebes who solved the riddle of the Sphinx, a fabled monster. [524] Prunella. A widely scattered plant, called self-heal, because a decoction of its leaves and stems was, and to some extent is, valued as an application to wounds. An editor comments on the fact that during the last years of Emerson's life "the little blue self-heal crept into the grass before his study window." SHAKESPEARE; OR, THE POET