silicate.

The most comprehensive account of the British chalk is contained in
the _Memoirs of the Geological Survey of the United Kingdom_, "The
Cretaceous Rocks of Britain," vol. ii. 1903, vol. iii. 1904 (with
bibliography), by Jukes-Browne and Hill. See also "The White Chalk of
the English Coast," several papers in the _Proceedings of the
Geologists' Association_, London, (1) Kent and Sussex, xvi. 1900, (2)
Dorset, xvii., 1901, (3) Devon, xviii., 1903, (4) Yorkshire, xviii.,
1904. (J. A. H.)

CHALKHILL, JOHN (fl. 1600?), English poet. Two songs by him are included
in Izaak Walton's _Compleat Angler_, and in 1683 appeared "Thealma and
Clearchus. A Pastoral History in smooth and easie Verse. Written long
since by John Chalkhill, Esq., an Acquaintant and Friend of Edmund
Spencer" (1683), with a preface written five years earlier by Walton.
Another poem, "Alcilia, Philoparthens Loving Follie" (1595, reprinted in
vol. x. of the _Jahrbuch des deutschen Shakespeare-Vereins_), was at one
time attributed to him. Nothing further is known of the poet, but a
person of his name occurs as one of the coroners for Middlesex in the
later years of Queen Elizabeth's reign. Professor Saintsbury, who
included _Thealma and Clearchus_ in vol. ii. of his _Minor Poets of the
Caroline Period_ (Oxford, 1906), points out a marked resemblance between
his work and that of William Chamberlayne.

CHALKING THE DOOR, a Scottish custom of landlord and tenant law. In
former days the law was that "a burgh officer, in presence of witnesses,
chalks the most patent door forty days before Whit Sunday, having made
out an execution of 'chalking,' in which his name must be inserted, and
which must be subscribed by himself and two witnesses." This ceremony
now proceeds simply on the verbal order of the proprietor. The execution
of chalking is a warrant under which decree of removal will be
pronounced by the burgh court, in virtue of which the tenant may be
ejected on the expiration of a charge of six days.

CHALLAMEL, JEAN BAPTISTE MARIUS AUGUSTIN (1818-1894), French historian,
was born in Paris on the 18th of March 1818. His writings consist
chiefly of popular works, which enjoyed great success. The value of some
of his books is enhanced by numerous illustrations, e.g. _Histoire-musee
de la Revolution francaise_, which appeared in 50 numbers in 1841-1842
(3rd ed., in 72 numbers, 1857-1858); _Histoire de la mode en Franc