Christie (London, 1896, fol.). Of his other works perhaps the most
important are: the editing of Frankfurts Reichskorrespondenz, 1376–1519
(Freiburg, 1863–1872); and of the Leben, Briefe und kleinere
Schriften of his friend J. F. Böhmer (Leipzig, 1868); a monograph,
Schiller als Historiker (Freiburg, 1863); and Zeit- und Lebensbilder
(Freiburg, 1875).
See L. Pastor, Johannes Janssen (Freiburg, 1893); F. Meister, Erinnerung an Johannes Janssen (Frankfort, 1896); Schwann, Johannes Janssen und die Geschichte der deutschen Reformation (Munich, 1892).
JANSSEN, PIERRE JULES CÉSAR (1824–1907), French astronomer, was born in Paris on the 22nd of February 1824, and studied mathematics and physics at the faculty of sciences. He taught at the lycée Charlemagne in 1853, and in the school of architecture 1865–1871, but his energies were mainly devoted to various scientific missions entrusted to him. Thus in 1857 he went to Peru in order to determine the magnetic equator; in 1861–1862 and 1864, he studied telluric absorption in the solar spectrum in Italy and Switzerland; in 1867 he carried out
optical and magnetic experiments at the Azores; he successfully
observed both transits of Venus, that of 1874 in Japan, that of
1882 at Oran in Algeria; and he took part in a long series of
solar eclipse-expeditions, e.g. to Trani (1867), Guntoor (1868),
Algiers (1870), Siam (1875), the Caroline Islands (1883), and to
Alcosebre in Spain (1905). To see the eclipse of 1870 he escaped
from besieged Paris in a balloon. At the great Indian eclipse
of 1868 he demonstrated the gaseous nature of the red prominences,
and devised a method of observing them under ordinary
daylight conditions. One main purpose of his spectroscopic
inquiries was to answer the question whether the sun contains
oxygen or not. An indispensable preliminary was the virtual
elimination of oxygen-absorption in the earth’s atmosphere,
and his bold project of establishing an observatory on the top of
Mont Blanc was prompted by a perception of the advantages to
be gained by reducing the thickness of air through which
observations have to be made. This observatory, the foundations
of which were fixed in the snow that appears to cover the
summit to a depth of ten metres, was built in September 1893,
and Janssen, in spite of his sixty-nine years, made the ascent
and spent four days taking observations. In 1875 he was
appointed director of the new astrophysical observatory established
by the French government at Meudon, and set on
foot there in 1876 the remarkable series of solar photographs
collected in his great Atlas de photographies solaires (1904).
The first volume of the Annales de l’observatoire de Meudon
was published by him in 1896. He died at Paris on the 23rd of
December 1907.
See A. M. Clerke, Hist. of Astr. during the 19th Century (1903); H. Macpherson, Astronomers of To-Day (1905).
JANSSENS (or Jansens), VICTOR HONORIUS (1664–1739), Flemish painter, was born at Brussels. After seven years in the studio of an obscure painter named Volders, he spent four years in the household of the duke of Holstein. The next eleven
years Janssens passed in Rome, where he took eager advantage
of all the aids to artistic study, and formed an intimacy with
Tempesta, in whose landscapes he frequently inserted figures.
Rising into popularity, he painted a large number of cabinet
historical scenes; but, on his return to Brussels, the claims of
his increasing family restricted him almost entirely to the larger
and more lucrative size of picture, of which very many of the
churches and palaces of the Netherlands contain examples. In
1718 Janssens was invited to Vienna, where he stayed three
years, and was made painter to the emperor. The statement
that he visited England is based only upon the fact that certain
fashionable interiors of the time in that country have been
attributed to him. Janssen’s colouring was good, his touch
delicate and his taste refined.
JANSSENS (or Jansens) VAN NUYSSEN, ABRAHAM (1567–1632), Flemish painter, was born at Antwerp in 1567. He studied under Jan Snellinck, was a “master” in 1602, and in 1607 was dean of the master-painters. Till the appearance of Rubens he was considered perhaps the best historical painter
of his time. The styles of the two artists are not unlike. In
correctness of drawing Janssens excelled his great contemporary;
in bold composition and in treatment of the nude he equalled
him; but in faculty of colour and in general freedom of disposition
and touch he fell far short. A master of chiaroscuro,
he gratified his taste for strong contrasts of light and shade
in his torchlights and similar effects. Good examples of this
master are to be seen in the Antwerp museum and the Vienna
gallery. The stories of his jealousy of Rubens and of his
dissolute life are quite unfounded. He died at Antwerp in
1632.
JANUARIUS, ST, or San Gennaro, the patron saint of Naples. According to the legend, he was bishop of Benevento, and flourished towards the close of the 3rd century. On the outbreak of the persecution by Diocletian and Maximian, he was taken to Nola and brought before Timotheus, governor of Campania, on account of his profession of the Christian religion.
After various assaults upon his constancy, he was sentenced to
be cast into the fiery furnace, through which he passed wholly
unharmed. On the following day, along with a number of fellow
martyrs, he was exposed to the fury of wild beasts, which,
however, laid themselves down in tame submission at his feet.
Timotheus, again pronouncing sentence of death, was struck
with blindness, but immediately healed by the powerful intercession
of the saint, a miracle which converted nearly five
thousand men on the spot. The ungrateful judge, only roused
to further fury by these occurrences, caused the execution of
Januarius by the sword to be forthwith carried out. The body
was ultimately removed by the inhabitants of Naples to that
city, where the relic became very famous for its miracles, especially
in counteracting the more dangerous eruptions of Vesuvius.
Whatever the difficulties raised by his Acta, the cult of St
Januarius, bishop and martyr, is attested historically at Naples
as early as the 5th century (Biblioth. hagiog. latina, No. 6558).
Two phials preserved in the cathedral are believed to contain the
blood of the martyr. The relic is shown twice a year—in May
and September. On these occasions the substance contained
in the phial liquefies, and the Neapolitans see in this phenomenon
a supernatural manifestation. The “miracle of St Januarius”
did not occur before the middle of the 15th century.
A great number of saints of the name of Januarius are mentioned in the martyrologies. The best-known are the Roman martyr (festival, the 10th of July), whose epitaph was written by Pope Damasus (De Rossi, Bullettino, p. 17, 1863), and the martyr of Cordova, who forms along with Faustus and Martialis the group designated by Prudentius (Peristephanon, iv. 20) by the name of tres coronae. The festival of these martyrs is celebrated on the 13th of October.
See Acta sanctorum, September, vi. 761–891; G. Scherillo, Esame di un codice greco pubblicato nel tomo secondo della bibliotheca casinensis (Naples, 1876); G. Taglialatela, Memorie storico-critiche del culto del sangue di S. Gennaro (Naples, 1893), which contains many facts, but little criticism; G. Albini, Sulla mobilità dei liquidi viscosi non omogenei (Società reale di Napoli, Rendiconti, 2nd series, vol. iv., 1890); Acta sanctorum, October, vi. 187–193. (H. De.)
JANUARY, the first month in the modern calendar, consisting
of thirty-one days. The name (Lat. Januarius) is derived from
the two-faced Roman god Janus, to whom the month was
dedicated. As doorkeeper of heaven, as looking both into the
past and the future, and as being essentially the deity who
busied himself with the beginnings of all enterprises, he was
appropriately made guardian of the fortunes of the new year.
The consecration of the month took place by an offering of meal,
salt, frankincense and wine, each of which was new. The
Anglo-Saxons called January Wulfmonath, in allusion to the
fact that hunger then made the wolves bold enough to come into
the villages. The principal festivals of the month are: New
Year’s Day; Feast of the Circumcision; Epiphany; Twelfth-Day;
and Conversion of St Paul (see Calendar).
JANUS, in Roman mythology one of the principal Italian deities. The name is generally explained as the masculine form of Diana (Jana), and Janus as originally a god of light and day, who gradually became the god of the beginning and origin of all things. According to some, however, he is simply the god
