The intervening notes of the chromatic scale are obtained by means of valves or pistons usually four in number, which by opening a passage into additional lengths of tubing lower the pitch one, half, one-and-a-half, two-and-a-half tones (see [Bombardon]; [Tuba]; [Valves]). The euphonium gives out the fundamental, or first note of the harmonic series, readily, but no harmonic above the eighth. Euphoniums are made in C and in B♭, the latter being more generally used. By means of all the valves used at once, the B♭, an octave below the fundamental, can be reached, giving a compass of four octaves, with chromatic intervals. The bass clef is used in notation. The euphonium is treated by French and German composers as a transposing instrument; in England the real notes are usually written, except when the treble clef is used. The quality of tone is rich and full, harmonizing well with that of the trombone. The euphonium speaks readily in the lower register, but slowly, of course, owing to the long dip of the pistons. Messrs Rudall Carte have removed this difficulty by their patent short action pistons, which have but half the dip of the old pistons. On these instruments it is easy to execute rapid passages.
The euphonium is frequently said to be a saxhorn, corresponding to the baryton member of that family, but the statement is misleading. The bombardon and euphonium, like the saxhorns, are the outcome of the application of valves to the bugle family, but there is a radical difference in construction; the tubas (bombardon and euphonium) have a conical bore of sufficiently wide calibre to allow of the production of the fundamental harmonic, which is absent in the saxhorns. The Germans classify brass wind instruments as whole and half[1] according to whether, having the wide bore of the bugle, the whole length of the tube is available and gives the fundamental proper to an organ pipe of the same length or whether by reason of the narrow bore in proportion to the length, only half the length of the instrument is of practical utility, the harmonic series beginning with the second harmonic. (See [Bombardon].)
(K. S.)
[1] See Dr Schafhäutl’s article on “Musical Instruments” in sect. iv. of Bericht der Beurtheilungs- Commission bei der Allg. deutschen Industrie Ausstellung (Munich, 1854), pp. 169-170; also Fried. Zamminer, Die Musik und die Musikinstrumente in ihrer Beziehung zu den Gesetzen der Akustik (Giessen, 1855).
EUPHORBIA, in botany, a large genus of plants from which the order Euphorbiaceae takes its name. It includes more than 600 species and is of almost world-wide distribution. It is represented in Britain by the spurges—small, generally smooth, herbaceous plants with simple leaves and inconspicuous flowers arranged in small cup-like heads (cyathia). The cyathium is a characteristic feature of the genus, and consists of a number of male flowers, each reduced to a single stamen, surrounding a central female flower which consists only of a stalked pistil; the group of flowers is enveloped in a cup formed by the union of four or five bracts, the upper part of which bears thick, conspicuous, gland-like structures, which in exotic species are often brilliantly coloured, giving the cyathium the appearance of a single flower. Another characteristic is the presence of a milky juice, or latex, in the tissues of the plant. In one section of the genus the plants resemble cacti, having a thick succulent stem and branches with the leaves either very small or completely reduced to a small wart-like excrescence, with which is generally associated a tuft of spines (a reduced shoot). These occur in the warmer parts of the world as a type of dry country or desert vegetation. The only species of note are E. fulgens and E. jacquiniaeflora, for the warm greenhouse; E. Cyparissias (the Cypress spurge), E. Wulfeni, E. Lathyris and E. Myrsinites, for the open air.
EUPHORBIACEAE, in botany, a large natural order of flowering plants, containing more than 220 genera with about 4000 species, chiefly tropical, but spreading over the whole earth with the exception of the arctic and cold alpine zones. They are represented in Britain by the spurges (Euphorbia, q.v.) (fig. 1) and dog’s mercury (Mercurialis) (fig. 2), which are herbaceous plants, but the greater number are woody plants and often trees. The large genus Euphorbia shows great variety in habit; many species, like the English spurges, are annual herbs, others form bushes, while in the desert regions of tropical Africa and the Canary Islands species occur resembling cacti, having thick fleshy stems and leaves reduced to spines. Another large genus, Phyllanthus, contains small annual herbs as well as trees, while in some species the leaves are reduced to scales, and the branches are flattened, forming phylloclades. The leaves also show great variety in form and arrangement, being simple and entire as in the English spurges, or deeply cut as in Ricinus (castor-oil) (fig. 3), and Manihot or sometimes palmately compound (Hevea). The majority contain a milky juice or latex in their tissues which exudes on cutting or bruising. In Hevea, Manihot and others the latex yields caoutchouc. The flowers are unisexual; male and female flowers are borne on the same, as in the spurges (fig. 1), or on different plants, as in dog’s mercury (fig. 2). Their arrangement shows considerable variation, but the flowers are generally grouped in crowded definite partial inflorescences, which are themselves arranged in spikes or stand in the axils of the upper leaves. These partial inflorescences are generally unisexual, the male often containing numerous flowers while the female flowers are solitary. The partial inflorescence (cyathium) of Euphorbia (fig. 1) resembles superficially a hermaphrodite flower. It contains a central terminal flower, consisting of a naked pistil; below this are borne four or five bracts which unite to form a cup-shaped involucre resembling a calyx; each of these bracts subtends a small cyme of male flowers each consisting only of one stamen. Between the segments of the cup are large oval or crescent-shaped glands which are often brightly coloured, forming petal-like structures.