heats of similar elements and compounds, but considering the
great variations of specific heat with temperature and physical state,
in alloys, mixtures or solutions, and in allotropic or other
modifications, it would be idle to expect that the specific heat of a
compound could be accurately deduced by any simple additive process
from that of its constituents.

AUTHORITIES.--Joule's _Scientific Papers_ (London, 1890); Ames and
Griffiths, _Reports to the International Congress_ (Paris, 1900), "On
the Mechanical Equivalent of Heat," and "On the Specific Heat of
Water"; Griffiths, _Thermal Measurement of Energy_ (Cambridge, 1901);
Callendar and Barnes, _Phil. Trans._ A, 1901, "On the Variation of the
Specific Heat of Water"; for combustion methods, see article
THERMOCHEMISTRY, and treatises by Thomsen, Pattison-Muir and
Berthelot; see also articles THERMODYNAMICS and VAPORIZATION.
(H. L. C.)

CALOVIUS, ABRAHAM (1612-1686), German Lutheran divine, was born at
Mohrungen in east Prussia, on the 16th of April 1612. After studying at
Konigsberg, in 1650 he was appointed professor of theology at
Wittenberg, where he afterwards became general superintendent and
primarius. He died on the 25th of February 1686. Calovius was the most
noteworthy of the champions of Lutheran orthodoxy in the 17th century.
He strongly opposed the Catholics, Calvinists and Socinians, attacked in
particular the reconciliation policy or "syncretism" of Georg Calixtus
(cf. the _Consensus repetitus fidei vere lutheranae_, 1665), and as a
writer of polemics he had few equals. His chief dogmatic work, _Systema
locorum theologicorum_ (12 vols. 1655-1677), represents the climax of
Lutheran scholasticism. In his _Biblia Illustrata_ (4 vols.), written
from the point of view of a very strict belief in inspiration, his
object is to refute the statements made by Hugo Grotius in his
Commentaries. His _Historia Syncretistica_ (1682) was suppressed.

CALPURNIUS, TITUS, Roman bucolic poet, surnamed SICULUS from his
birthplace or from his imitation of the style of the Sicilian
Theocritus, most probably flourished during the reign of Nero. Eleven
eclogues have been handed down to us under his name, of which the last
four, from metrical considerations and express MS. testimony, are now
generally attributed to Nemesianus (q.v.), who lived in the time of the
emperor Carus and his sons (latter half of the 3rd century A.D.). Hardly