532 M I T M N E subject. We may in particular refer to his discovery of the relation of benzene to benzoic acid, of nitro-benzene, and of a considerable number of the derivatives of benzene. In 1833 he published his Lehrbuch der Chemie, a student s text-book of chemistry of the most thoroughly practical and yet rigidly scientific kind, from the study of which teachers of chemistry may still derive many a valuable hint. His interest in mineralogy led him to the study of the geology of volcanic regions, and he made frequent visits to the Eifel with a view to the discovery of a theory of volcanic action. He did not, however, publish any papers on the subject, but since his death his notes have been arranged and published by Dr Koth in the Memoirs of the Berlin Academy (1866). In December 1861 symptoms of heart disease made their appearance, but he was able to carry on his academical work till December 1862. He died at Schoneberg near Berlin on 28th August 1863. Mitscherlich s published papers are chiefly to be found in the Abhandlunycii of the Berlin Academy, in Poggendorffs Annalen, and in the Annalcs dc Chimic ct dc Physique. The fourth edition of the Lehrbuck dcr Chemie was published in 1844 ; a fifth was begun in 1855, but was not completed. (A. C. B. ) MITYLENE, or MYTILENE. See LESBOS. MIZPAH (nBTO) and MIZPEH (nBVP) are Hebrew words for a "place of prospect," or high commanding point. The cities of Palestine generally occupied such positions ; and so in the Old Testament we find several places bearing the name of "The Mizpah" (Mizpeh). Sometimes a determining genitive is added ; " The Mizpeh of Gilead " (Judg. xi. 29), "The Mizpeh of Moab" (1 Sam. xxii. 3). (1) The most famovis of these places is that in Gilead, a noted sanctuary (Judg. xi. 11 ; Hosea v. 1), claiming consecration from the sacrifice of Jacob (Gen. xxxi. 54) and the masscba or sacred stone erected by him (ver. 45). The narrative of Gen. xxxi. 45 sq. is somewhat obscure, and not all from one hand. We gather, however, from it that another name of " The Mizpah " was Galeed, i.e., Gilead. Thus Mizpah, Mizpeh Gilead, Gilead (Hos. vi. 8), Kamath Mizpeh (i.e., the height of Mizpeh, Josh. xiii. 26), and Ramoth Gilead (the heights of Gilead), or simply The Ramah (2 Kings viii. 28, 29), are almost universally taken to be one place. With this it agrees that Ramoth Gilead was a city of refuge, which points to an early sanctity. The place is prominent throughout the liistory. It was the seat of Jephthah (Judg. xi. ), the mourning for whose daughter probably gives us a glimpse into the ancient rites of a provincial sanctuary, the residence of one of Solomon s officers (1 Kings iv. 13), and a hotly disputed frontier city in the wars between Syria and the house of Omri, before which Ahab fell (1 Kings xxii. ), and in which the military revolt of Jehu was organized (2 Kings ix.). Maspha was still a strong place in the Greek period, and was taken by Judas Maccabams (1 Mac. v. 35). Eusebius knows Ramoth as a place 15 miles west of Philadelphia or Rabbah of Ammon. It is therefore commonly identified with El-Salt, the modern capital of the Belka ; but this cannot be said to be made out. (2) The Benjamite Mizpah or Mizpeh, also a sanctuary, is often named in the history of Samuel. It was a border fortress of King Asa (1 Kings xv. 22), and the residence of Gedaliah as governor of Judnea after the fall of Jerusalem (Jer. xl.). Its old sanctity was still remembered in the Maccabee times, and from 1 Mac. iii. 46 we conclude that it commanded a view of Jerusalem. The most prob able identification is with the prominent hill-top of Neby Samwil. There was (3) another Mizpeh in the low country of Judah (Josh. xv. 38), and (4) a land or valley of Mizpeh (Josh. xi. 3, 8) under Mount Hermon. MNEMONICS, or artificial helps to the memory, have been employed in a more or less systematic form from a very early period. Mnemonics (TO /u,v?///ovtK6V, sc. Te^i ?//xa or TrapuyyeA/xa) were much cultivated by Greek sophists and philosophers, and are repeatedly referred to by Plato and Aristotle. In later times the invention was ascribed to the poet Simonides, 1 perhaps for no other reason than that the strength of his memory was famous. Cicero, who attaches considerable importance to the art, but more to the principle of order as the best help to memory, speaks 1 Pliny, //. N., vii. 24. Cicero, De Or., ii, 86, mentions this belief without committing himself to it. of Carneades (or perhaps Charmades) of Athens and Metro- dorus of Scepsis as distinguished examples of the use of well-ordered images to aid the memory. The latter is said by Pliny to have carried the art so far ut nihil non iisdem verbis redderet auditum. The Romans valued such helps as giving facility in public speaking. The method used is described by the author of Rhet. ad Heren., iii. 16- 24; see also Quintilian (Inst. Or., x. 1, 2), whose account is, however, somewhat incomplete and obscure. In his time the art had almost ceased to be practised. The Greek and Roman system of mnemonics was founded on the use of mental places and signs or pictures. The thing to be re membered was localized in the imagination, and associated with a symbol which concretely represented what it was desired to retain in the memory, special care being taken that the symbols should be as vivid, pleasing, and impres sive as possible. The most usual method was to choose a large house, of which the apartments, walls, windows, statues, furniture, &c., were severally associated with cer tain names, phrases, events, or ideas, by means of symbolic pictures ; and to recall these it was only necessary to searcli over the apartments of the house, till the particular placi; was discovered where they had been deposited by the ima gination. As the things to be remembered increased, new houses could be built, each set apart to a certain class of ideas or events, and these houses Avere again constructed into a mnemonic town. In accordance with this system, if it were desired to fix an historic date in the memory, it was localized in an imaginary town divided into a certain number of districts, each with ten houses, each house with ten rooms, and each room with a hundred quadrates or memory-places, partly on the floor, partly on the four walls, partly on the roof. Thus, if it Avere desired to fix in the memory the date of the invention of printing (1436), an imaginary book, or some other symbol of printing, Avould be placed in the thirty-sixth quadrate or memory-place of the fourth room of the first house of the historic district of the toAvn. The success of the method depended largely on the poAver of the imagination to give the different houses, rooms, etc., characteristic A r arieties of aspect, and AVC may suppose that it Avas the effort to frame suitable images and places, giving an adventitious interest to dry details, that constituted the real advantage of the system. Except that the rules of mnemonics are referred to by Martianus Capella, nothing further is knoAvn regarding the practice of the art until the 13th century, AA hen the system of the Romans AA r as revived and a good many treatises were published on the subject. Among the A r oluminous AATit- ings of Roger Bacon is a tractate De Arte Memorativa, Avhich exists in MS. at Oxford. Raymond Lully devoted special attention to mnemonics in connexion with his ars yeneralis. The first important modification of the method of the Romans Avas that invented by Conrad Celtes, a, German poet, who, in his Epitoma in utramque Ciceroni* rhetoricam cum arte memorativa nova (1492), instead of places made use of the letters of the alphabet. About the end of the loth century Petrus de Ravenna aAvakened such astonishment in Italy by his mnemonic feats that he Avas believed by many to be a necromancer. His Phoenix Artis Memorise, published at Venice in 1 491 in four volumes, Avent through as many as nine editions, the seventh appear ing at Cologne in 1608. An impression equally great Avas produced about the end of the 16th century by Lambert Schenkel, who taught mnemonics in France, Italy, and Germany, and, although he Avas denounced as a sorcerer by the university of Louvain, published in 1593 his tractate De Memoria at Douai Avith the sanction of that celebrated theological faculty. The most complete account of his sys tem is given in tAvo Avorks by his pupil Martin Sommer, pub
lished at Venice in 1619. Giordano Bruno, in connexion