of God. It is an extraordinary book, full of apocryphal
history, 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 Senor 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 Gumbel 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 Handworterbuch; 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 (Frejus) 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 Taus (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 of the
Caledonians. Having explored the coasts of Fife and Forfar, he
gained a decisive victory over the Caledonians under Galgacus
at the Graupian hill (see BRITAIN, Roman.) His successes,
however, had aroused the envy and suspicion of Domitian.
He was recalled to Rome, where he lived a life of studied
retirement, to avoid the possibility of giving offence to the
tyrant. He died in 93, poisoned, it was rumoured, by the
emperor's orders. The Life of Agricola by his son-in-law
Tacitus is practically a panegyric or funeral oration.
See Urlichs, De Vita et Honoribus Agricolae (1868);
Dio Cassius xxxix. 50, lxvi. 20: Mommsen, Provinces of
the Roman Empire (Eng. trans., 1886), i. 183-184, 194.
AGRICOLA, JOHANN FRIEDRICH (1720-1774), German musician, was
born at Dobitschen in Saxe-Altenburg, on the 4th of January
1720. While a student of law at Leipzig he studied music
under Johann Sebastian Bach. In 1741 he went to Berlin,
where he studied musical composition. He was soon generally
recognized as one of the most skilful organists of his time;
and in 1751, as the result of a comic opera, Il Filosofo
convinto in amore, performed at Potsdam, he was made court
composer to Frederick the Great. He died in Berlin on the
1st of December 1774. In 1759, on the death of Karl Heinrich
Graun, he was appointed conductor of the royal orchestra.
Besides several operas of merit, he composed instrumental
pieces and church music. His reputation chiefly rests,
however, on his theoretical and critical writings on musical
subjects. He wrote under the pseudonym of Flavio Anicio Olibrio.
AGRICOLA (originally SCHNEIDER, then SCHNITTER), JOHANNES
(1494-1566), German Protestant reformer, was born on the 20th of
April 1494, at Eisleben, whence he is sometimes called Magister
Islebius. He studied at Wittenberg, where he soon gained the
friendship of Luther. In 1519 he accompanied Luther to the great
assembly of German divines at Leipzig, and acted as recording
secretary. After teaching for some time in Wittenberg, he
went to Frankfort in 1525 to establish the reformed mode of
worship. He had resided there only a month when he was called
to Eisleben, where he remained till 1526 as teacher in the
school of St Andrew, and preacher in the Nicolai church. In
1536 he was recalled to teach in Wittenberg, and was welcomed by
Luther. Almost immediately, however, a controversy, which
