visions and scholasticism, which professes to have been written by divine inspiration, and is devoted to praise of the Virgin. In 1642 she sent to Philip IV. an account of a vision she had had, of a council of the infernal powers for the destruction of Catholicism and Spain. The king visited her when on his way to Aragon to suppress the rebellion of Catalonia. A long correspondence, which lasted till her death on the 29th of March 1665, was begun. The king folded a sheet of paper down the middle and wrote on the one side of the division. The answers were to be written on the other and the sheet returned. By a pious fraud copies were kept at Agreda. How far Maria was only the mouthpiece of the Franciscans must of course be a matter of doubt. Her correspondence was apparently suspended whenever her confessor was absent. She must, however, have co-operated at least, and it is certain that the Franciscans, who were very unfortunate in some of their pious women, owed not a little to her. The letters are in excellent Spanish, are curious reading, and are invaluable as illustrations for the second part of the reign of Philip IV.
The correspondence of Sor Maria with the king has been published in full by Don F. Siluela, Cartas de la Venerable Madre Sor Maria de Agreda y del Señor Rey Don Filipe IV. (Madrid, 1885). The Mystic City of God is one of the most characteristic monuments of Mariolatry, and has continued to be much in favour with supporters of the dogma of the Immaculate Conception. It appeared in Madrid in 1668, with a biographical introduction by Samaniego, has been often reprinted, and was translated into French and Italian. It was for a time reserved by the Index, both Spanish and Papal, but was taken off by the influence of the Franciscans and of Spain, the chief supporters of the Immaculate Conception. An account of Maria de Agreda will be found in the Tracts of Michael Geddes (London, 1706), vol. iii., written by a competent critic and Anglican divine of the 18th century who detested “enthusiasm.” (D. H.)
AGRICOLA, CHRISTOPH LUDWIG (1667–1719), German landscape painter, was born and died at Regensburg (Ratisbon). He spent a great part of his life in travel, visiting England, Holland and France, and residing for a considerable period at Naples. His numerous landscapes, chiefly cabinet pictures, are remarkable for fidelity to nature, and especially for their skilful representation of varied phases of climate. In composition his style shows the influence of Caspar Poussin, while in light and colour he imitates Claude Lorraine. His pictures are to be found in Dresden, Brunswick, Vienna, Florence, Naples and many other towns of both Germany and Italy.
AGRICOLA (the Latinized form of the name Bauer), GEORG (1490–1555), German scholar and man of science, known as “the father of mineralogy,” was born at Glauchau in Saxony on the 24th of March 1490. Gifted with a precocious intellect, he early threw himself into the pursuit of the “new learning,” with such effect that at the age of twenty he was appointed Rector extraordinarius of Greek at the so-called Great School of Zwickau, and made his appearance as a writer on philology. After two years he gave up his appointment in order to pursue his studies at Leipzig, where, as rector, he received the powerful support of the professor of classics, Peter Mosellanus (1493–1524), a celebrated humanist of the time, with whom he had already been in correspondence. Here he also devoted himself to the study of medicine, physics and chemistry. After the death of Mosellanus he went for a short time to Italy, where he took his doctor’s degree. On his return he settled as practising physician in the Joachimstal, a centre of mining and smelting works, his object being partly “to fill in the gaps in the art of healing,” partly to test what had been written about mineralogy by careful observation of ores and the methods of their treatment. His thorough grounding in philology and philosophy had accustomed him to systematic thinking, and this enabled him to construct out of his studies and observations of minerals a logical system which he began to publish in 1528. Bermannus, sive de re metallica dialogus, the first attempt to reduce to scientific order the knowledge won by practical work, brought Agricola into notice. In 1530 Prince Maurice of Saxony appointed him historiographer with an annual allowance, and he migrated to Chemnitz, the centre of the mining industry, in order to widen the range of his observations. The citizens showed their appreciation of his learning by appointing him town physician and electing him burgomaster. His popularity was, however, short-lived. Chemnitz was a violent centre of the Protestant movement, while Agricola never wavered in his allegiance to the old religion; and he was forced to resign his office. He now lived apart from the contentious movements of the time, devoting himself wholly to learning. His chief interest was still in mineralogy; but he occupied himself also with medical, mathematical, theological and historical subjects, his chief historical work being the Dominatores Saxonici a prima origine ad hanc aetatem, published at Freiberg. In 1544 he published the De ortu et causis subterraneorum, in which he laid the first foundations of a physical geology, and criticized the theories of the ancients. In 1545 followed the De natura eorum quae effluunt e terra; in 1546 the De veteribus et novis metallis, a comprehensive account of the discovery and occurrence of minerals; in 1548 the De animantibus subterraneis; and in the two following years a number of smaller works on the metals. His most famous work, the De re metallica, libri xii., was published in 1556, though apparently finished several years before, since the dedication to the elector and his brother is dated 1550. It is a complete and systematic treatise on mining and metallurgy, illustrated with many fine and interesting woodcuts and containing, in an appendix, the German equivalents for the technical terms used in the Latin text. It long remained a standard work, and marks its author as one of the most accomplished chemists of his time. Believing the black rock of the Schlossberg at Stolpen to be the same as Pliny’s basalt, he applied this name to it, and thus originated a petrological term which has been permanently incorporated in the vocabulary of science.
In spite of the early proof that Agricola had given of the tolerance of his own religious attitude, he was not suffered to end his days in peace. He remained to the end a staunch Catholic, though all Chemnitz had gone over to the Lutheran creed; and it is said that his life was ended by a fit of apoplexy brought on by a heated discussion with a Protestant divine. He died at Chemnitz on the 21st of November 1555, and so violent was the theological feeling against him, that he was not suffered to rest in the town to which he had added lustre. Amidst hostile demonstrations he was carried to Zeitz, seven miles from Chemnitz, and there buried.
See article by Gümbel in Allgem. Deutsche Biog. (1875); F. L. Becher, Georg Agricola und Werner (Freiberg, 1819); F. A. Schmidt, Georg Agricola’s Bermannus mit Einleitung (Freiberg, 1806); Poggendorff, Biographisches Handwörterbuch; Agricola’s works passim.
AGRICOLA, GNAEUS JULIUS (A.D. 37–93), Roman statesman and general, father-in-law of the historian Tacitus, was born on the 13th of June A.D. 37 (according to others, 39) at Forum Julii (Fréjus) in Gallia Narbonensis. His father, Julius Graecinus, having been put to death by Caligula, Agricola was brought up by his mother Julia Procilla. After studying philosophy at Massilia, he entered the army and served (59) under Suetonius Paulinus in Britain. In 61 he returned to Rome, where he married Domitia Decidiana, a Roman lady of distinction. In 63 he was quaestor in Asia, in 65 tribune, in 68 praetor, and when Vespasian was proclaimed emperor, he immediately declared himself his supporter. In 70 he was appointed to the command of the 20th legion in Britain, then stationed at Deva (Chester). On his return to Rome at the end of three years he was made censor, raised to the rank of patrician, and appointed governor of Aquitania (74–78). Appointed consul suffectus in the following year, he was admitted into the college of pontiffs and made governor of Britain. In the same year he betrothed his daughter to Tacitus. Although the legation of Britain lasted as a rule only three years, Agricola held the post for at least seven and succeeded in reconciling the inhabitants to Roman rule and inducing them to adopt the customs and civilization of their conquerors. His military achievements were equally brilliant. After conquering the Ordovices in North Wales and the island of Mona (Anglesey), during the next two years he carried his victorious arms to the Taüs (Tay; others read Tanaus, perhaps the north Tyne), and in his fourth campaign fortified the country between Clota and Bodotria (the firths of Clyde and Forth) as a protection against the attacks
