Czerny, KARL, pianoforte teacher and composer, born at Vienna in 1791, was the pupil and friend of Beethoven, and also gained much from Clementi and Hummel. Besieged by pupils, he would teach only those who showed especial talent; among these were Liszt, Thalberg, and Döller. Living in great retirement, he devoted much of his time to composition; a mass of MS. is preserved in the archives of Vienna, while his published works number over 900, of which his Theoretical and Practical School is the best known, and probably also the most valuable. He died 15th July 1857.

D

is the fourth letter in our own alphabet, as well as in the Phœnician, Hebrew, Greek, and Latin, from which last it was immediately derived. The original symbol in the Egyptian hieroglyphs was the picture of a hand. When taken over by the Phœnicians, this sign was called daeth, 'the door,' from a fancied resemblance to the curtained aperture of a tent, rather than to the wooden quadrangular door of a house. This resemblance may be traced in the Greek letter Δ, whose name delta was derived from the Semitic daeth. In Phœnician and the oldest Greek, the letter had a short tail, A, but as this form differed very little from that of B, and hardly at all from that of R, the three letters were differentiated, B acquiring a second loop, R a tail, while D lost the downward prolongation of the stem.

In eursive Greek the letter was rounded, and acquired the form δ, which is due to the ligature connecting it with the following letter. These changes are shown in the table given in Vol. I., page 187, which also explains the singular process whereby, in the minuscule form d, the loop of D has been transferred from the right of the stem to the left. In the Aramean alphabets the loop opened out, as is seen in the Hebrew ד.

The sound of D is the soft dental mute. It has, like t, an affinity for n, and is often brought in as a sort of shadow to facilitate the utterance of this letter. It is intrusive in such words as sound, eomound, lend, riband, gender, thunder, kindred. Sometimes it disappears, as in the case of cruel from crudelis, or winnow from windewe. It is often assimilated to the following consonant, especially in compounds derived from the Latin, as in the words accept, attain, allocation, appear, affirm, arrogant, gossip. It is sometimes replaced by l, r, or b, as in the words lacrina, Ulysses, lingua, arbiter, meridies, bellum, bonus, bis. By Grimm's Law a primitive d becomes t in English, and z in German: as in the words decem, ten, zehn; or duo, two, zwei. A primitive dth becomes th in Greek, th in German, f in Latin, and d in English; as the words thip, thier, fera, and deer. Di followed by a vowel sometimes becomes j, as in journal from diurnal.

D, the Roman numeral for 500, arose out of IO, the half of CI, which was the old way of writing ①, the primitive sign for 1000, which was afterwards written M.

D, in Music, is the second note in the natural scale. See MUSIC, SCALE.