| 588 | BERYL | BERZELIUS |
and turnips than most of them. Sheep and cattle are raised in great numbers. The coast is rugged, with no bays save at Coldingham and Eyemouth. Excepting the Eye in the northeast, all the streams are tributaries of the Tweed and abound with fish. The salmon fisheries, long suspended, have lately resumed some of their former importance. The chief trade is carried on through Berwick-on-Tweed. The only royal burgh is Lauder; the largest town is Dunse; and the county town is Greenlaw, 3 m. S. of which is Hume castle, on a hill 900 feet high. There are numerous relics of Roman and British encampments, and among the many antiquities are those of Fast castle (the Wolf's Crag of the “Bride of Lammermoor”), 2 m. from the celebrated St. Abb's Head promontory, and the ruins of Coldingham priory and of Dryburgh abbey.
BERYL (Gr. βήρυλλος), a mineral composed of silica 66.8, alumina 19.1, glucina 14.1 = 100. The union of the emerald and beryl in one species, which Pliny says was suggested in his time, was first recognized on crystallographic grounds by De Lisle, and more satisfactorily through measurements of angles by Haüy, and chemically by Vauquelin. The beryl, emerald or smaragd, and aquamarine are all the same mineral species, and only distinguished from each other by their blue and yellow shades of green, or by the delicacy of the crystals. The beryl is sometimes also white. The emerald is more transparent and of finer colors than the beryl, and makes a handsomer gem. Aquamarine is a beautiful sea-green variety. The brilliant green color of the emerald is due to the presence of a minute quantity of oxide of chromium; beryl and aquamarine derive their colors from the oxide of iron. The beryl crystallizes in regular 6-sided prisms, which are often striated with longitudinal channels. Its hardness, rated at 7.5 to 8 on the mineralogical scale, is less than that of topaz and greater than that of quartz. Its specific gravity is 2.7. The crystals are found in metamorphic limestones, in slate, mica schist, gneiss, and granite rocks, generally as single crystals or in clusters, rather than in veins. There are many celebrated localities of gigantic beryls and beautiful emeralds in various parts of the world. Upper Egypt produced the mineral in ancient times, and it is still found in the mica slate of Mount Zabarah. Siberia, Hindostan, Limousin in France, Peru, and Colombia have all furnished splendid emeralds. The largest beryls known have been found in Acworth and Grafton, New Hampshire, and in Royalston, Massachusetts. One from Grafton measures 4 ft. 3 in. in length, 32 in. through in one direction and 22 in another transverse, and weighs 2,900 lbs. Another is estimated to weigh nearly 2½ tons, measuring 45 in. through in one direction and 24 in. in another. A crystal in the museum at Stockholm, found in Sweden, is considered to be the largest in Europe; it weighs 80 lbs. The value of the specimens is not at all dependent on their size. The large crystals are of coarse texture and feeble lustre, and possess no beauty. As the beryl expands by heat in a direction perpendicular to the principal axis, and contracts on the line of the axis, there is a point where the expansion and contraction exactly neutralize each other, and a section across this would maintain a constant length. Soleil recommends the cutting of prisms in conformity with this direction, to be used as normal units of measurement.
BERYTUS. See Beyrout.
BERZELIUS, Johan Jakob, baron, a Swedish chemist, born at Väfversunda, district of Linköping, Aug. 20, 1779, died in Stockholm, Aug. 7, 1848. His father was government schoolmaster in his native village, and was very poor. Berzelius received his early education at home, and in 1796, through the assistance of friends, commenced the study of medicine in the university of Upsal. The lectures at Upsal in those days were read without any experimental illustrations, and the instructions in the laboratory were of a superficial and unsatisfactory kind. He contrived, however, to obtain the means of making an analysis of a mineral water, and in 1800 published his first paper, entitled Nova Analysis Aquarum Medeviensium, which at once gained for him considerable local celebrity. In 1802 he became adjunct professor of medicine in Stockholm, at the same time practising his profession and delivering lectures on chemistry. At this period nearly all the scientific men of the world were attracted by Volta's discoveries to experiment with voltaic electricity, and Berzelius in 1803 published an important paper on the action of electric currents on solutions of salts, in which he first pointed out that combustible bodies, alkalies, and earths went to the negative pole, while oxygen and the acids went to the positive. Three years later Davy published similar views and extended his researches further than Berzelius, as he had far greater means at his command; in Davy's paper, however, no allusion is made to Berzelius, an omission which was at once supplied by the translators of Davy's article for the German and Swedish annals. In 1806 Berzelius was made teacher of chemistry at the military school of Carlberg, and in 1807 was appointed professor of medicine and pharmacy at the medical institute in Stockholm. At this time he constructed a battery consisting of zinc, copper, and two liquids so made that the zinc was not attacked by the liquid in which it was immersed, while the copper was rapidly oxidized. By aid of this apparatus and the employment of mercury at the negative pole, he succeeded early in 1808 in preparing the metals calcium, barium, and the supposed amalgam of ammonium. Simultaneously with his electrical researches he conducted the analysis of minerals, and in 1803, when he was only 23 years old, made the discovery of the metal cerium. While thus engaged it was necessary for him to
