622 HELLEN IIELMHOLTZ veratria and viridia, which produces the sedative effect upon the circulation just mentioned, and very little if any emetic or cathartic action. The fluid extract and tincture of V. viride have been largely employed, in doses of one, two, or three drops frequently repeated, in dis- eases attended with fever. It is doubtful, however, whether the curative effect over the disease corresponds to the lowering of the pulse. Pneumonia, peritonitis, and cardiac diseases are the affections in which it has been most employed. HELLEN. See GREECE, vol. viii., p. 187. HELLER, Joseph, a German author, born in Bamberg, Sept. 22, 1798, died there, June 4, 1849. He left mercantile pursuits for the study of art, made extensive collections, and wrote biographies of Lucas Cranach, Albrecht Dtirer, and other artists. Among his other works are Geschichte der Holzschneidekunst (Bamberg, 1822), and Handbuch far JTupferstichsamm- lung (3 vols., 1823-'36). HELLER, Karl Kartliolomans, a German natu- ralist, born in Moravia in 1824. In 1845 he made collections of natural history in Mexico and Central America for the horticultural so- ciety of Vienna, and on his home journey in 1848 he visited Cuba and the United States. In 1851 he became adjunct and in 1853 titular professor of natural history at the university of Gratz. His publications include Beitrdge zur ndheren Kenntniss Mittelamerikas (Gratz, 1853), Rei&en in Mexico (Leipsic, 1853), and Das dioptrische Mikroslcop (Vienna, 1856). HELLER, Stephan, a German composer, born in Pesth, Hungary, May 15, 1814. At the age of nine he played in public with his teacher Dussek's concerto for two pianos. He went soon after to Vienna, and received lessons from Czerny and Hrflm. In 1827 and 1828 he gave concerts in Vienna, and in 1829 went on a con- cert tour through Hungary and Germany. At the age of 16 he took up his residence at Augs- burg, remaining there until he went to Paris in 1838, where he has since for the most part resided. His compositions are almost exclu- sively for the pianoforte, and are distinguished by originality of thought and treatment, eleva- tion of style, and poetic refinement. Fe"tis ranks him as a composer for the pianoforte above Chopin. While this praise may be ex- aggerated, it is nevertheless true that Heller is one of the most poetic and captivating writers for that instrument. His published works number about 150, including many admirable arrangements for piano of the songs of Schu- bert, Mendelssohn, and other composers, and such original series as the Nuits blanches and the Wanderstunden. HELLESPONT (Gr. 'E/atfenrovrof, sea of Helle), in ancient geography, the narrow strait (now the Dardanelles) connecting the ^Egean sea with the Propontis (sea of Marmora), and sepa- rating the Thracian Chersonesus (peninsula of Gallipoli) from Asia Minor. HELL GATE. See BLASTING, vol. ii., p. 702. HELLIN, a town of Murcia, Spain, in the province and 35 m. S. by E. of the city of Alba- cete, situated on the slope of the Segura moun- tain chain, near the E. bank of the Mundo ; pop. about 10,000. It contains a large square and a number of smaller ones, a fine old parish church, and remains of a Roman castle. Trade is carried on in various goods manufactured here, in grain, wine, and silk, but chiefly in sulphur, from celebrated mines about 13 in. distant, which belong to the government, and were known to the Romans. Near the town is the hermitage of San Rosario, and at a dis- tance of about 6 m. the springs of Azaraque. HELM. See STEERING APPARATUS. II ELMERS, Jan Frederik, a Dutch poet, born in Amsterdam in 1767, died Feb. 26, 1813. His principal work is his national poem De Hollandsche natie ("The Dutch Nation") (Amsterdam, 1812, and many later editions), which has been translated into French by Auguste Clavereau. He published a collection of his poems (2 vols., Amsterdam, 1809-'10), and his posthumous writings appeared in Haar- lem in 1814-'15. HELMET SHELL (cassis), a genus of gastero- pod mollusks, separated by Lamarck from the Linna3an genus luccinum. About 40 species are described, living in shallow tropical seas in the East and West In- dies, on the east coast of Africa, in the Pa- cific, and in the Medi- terranean ; nearly as many fossil species have been found in the eocene of Chili and France. The shell is ventricose, with irregular rows of protuberan- ces on the whorls ; spire short ; aperture long, with the outer lip reflected and toothed, and the inner lip spread over the body whorl. The species are of considerable size, and many are used for the manufacture of cameos, the different colors of the layers of the shells ren- dering them well adapted for this purpose. In the C. cornuta the cameo would be white on an orange ground ; in C. tiiberosa and Madagas- cariemis (the queen conch of Madagascar), white on a dark claret color ; in C. ritfa, pale salmon color on orange. (See CAMEO.) HELMHOLTZ, Hermann Lndwig Ferdinand, a Ger- man physicist and physiologist, born in Potsdam, Aug. 31, 1821. At the age of 17 he was admit- ted to the royal military school in Berlin, and commenced the study of medicine. In 1842, in his graduating thesis entitled De Fabrica Sys- tematis Nervosi Evertebratum, he endeavored to prove the existence of an anatomical con- nection between the nerves of motion and those of sensation through the intermediate means of ganglion cells, and presented the re- sults of numerous examinations of the delicate nerve fibres of bugs, spiders, crab?, and many lower animals. Until 1843 he was assistant physician at the Charite" hospital, and then be- Helmct ShelL
