atise on _Granular Degeneration of the Kidneys_
(1839), and a _Commentary on the Pharmacopoeias of Great Britain_
(1842). Sir Robert Christison, who retained remarkable physical vigour
and activity down to extreme old age, died at Edinburgh on the 23rd of
January 1882.

See the _Life_ by his sons (1885-1886).

CHRISTMAS (i.e. the Mass of Christ), in the Christian Church, the
festival of the nativity of Jesus Christ. The history of this feast
coheres so closely with that of Epiphany (q.v.), that what follows must
be read in connexion with the article under that heading.

The earliest body of gospel tradition, represented by Mark no less than
by the primitive non-Marcan document embodied in the first and third
gospels, begins, not with the birth and childhood of Jesus, but with his
baptism; and this order of accretion of gospel matter is faithfully
reflected in the time order of the invention of feasts. The great church
adopted Christmas much later than Epiphany; and before the 5th century
there was no general consensus of opinion as to when it should come in
the calendar, whether on the 6th of January, or the 25th of March, or
the 25th of December.

The earliest identification of the 25th of December with the birthday of
Christ is in a passage, otherwise unknown and probably spurious, of
Theophilus of Antioch (A.D. 171-183), preserved in Latin by the
Magdeburg centuriators (i. 3, 118), to the effect that the Gauls
contended that as they celebrated the birth of the Lord on the 25th of
December, whatever day of the week it might be, so they ought to
celebrate the Pascha on the 25th of March when the resurrection befell.

The next mention of the 25th of December is in Hippolytus' (c. 202)
commentary on Daniel iv. 23. Jesus, he says, was born at Bethlehem on
the 25th of December, a Wednesday, in the forty-second year of Augustus.
This passage also is almost certainly interpolated. In any case he
mentions no feast, nor was such a feast congruous with the orthodox
ideas of that age. As late as 245 Origen, in his eighth homily on
Leviticus, repudiates as sinful the very idea of keeping the birthday of
Christ "as if he were a king Pharaoh." The first certain mention of Dec.
25 is in a Latin chronographer of A.D. 354, first published entire by
Mommsen.[1] It runs thus in English: "Year 1 after Christ, in the
consulate of Caesar and Paulus, the Lord Jesus Christ was born on the
25th of December, a Friday and 15th day