establishing his reputation as a jurist with the court and the bar.

BLACK, JOHN, a London journalist, born at Dunse, in the county of Berwick, in 1783, died June, 1855. He received the ordinary Scottish parochial education, and commenced active life at the age of 14 in his native place, as errand boy. In his 18th year, he removed to Edinburgh, where he struggled for several years, chiefly as writing clerk in a lawyer's office. He taught himself Latin, Greek, and French, and also acquired German and Italian. In 1810, at the age of 27, he arrived in London, with 3 half-pence in his pocket, having walked the whole way from Edinburgh. He had a letter to Mr. Perry, of the "Morning Chronicle," who engaged him first as a parliamentary reporter, and, soon after, as translator of the foreign journals. In 1819, 2 years before Mr. Perry's death, Mr. Black rose to the position of principal editor of that journal, in which his fearlessness, tact, probity, and general knowledge were largely available. When the "Morning Chronicle" was sold (in 1823 to Mr. Clements, and to Sir John Easthope in 1834), Mr. Black was continued as editor, and retired in 1844. He was then in such distressed circumstances, that he was compelled to sell his large and valuable library, the collection of over 30 years. The leaders of the liberal party, whose opinions he had devoted his life to advocating, subscribed enough to purchase him an annuity, on which he lived in easy circumstances, until his death. Mr. Black, whom Cobbett delighted to call "the Scotch feelosopher," was a heavy political writer, fond of filling his articles with long extracts from old books, and fully persuaded that his duty as a journalist was to write all the "leaders" himself. Latterly he had the assistance of many able writers. Indeed, while the "Chronicle" was in Mr. Perry's hands, almost every "old whig" of note occasionally contributed to it. Mr. Black never wrote an original book, but translated Humboldt's work on New Spain, Leopold's “Travels in Norway and Lapland," Goldoni's "Autobiography, and Schlegel's "Lectures on the Dramatic Arts and Literature."

BLACK, JOSEPH, a Scotch chemist, born of Scotch parentage at Bordeaux, in France, in 1728, died in Edinburgh, Nov. 26, 1799. He was sent in his 12th year to prosecute his studies at Belfast, and 6 years later to the university of Glasgow, where he displayed a fondness for physical science, selected the profession of medicine, and became the favorite pupil of Dr. Cullen, under whom he made great progress in chemical studies. Physicians and chemical professors were at that time discussing the cause of the causticity of lime and the mode of its action as a lithontriptic medicine, and Mr. Black, as the assistant of Dr. Cullen in his chemical operations, began to make experiments upon this subject, which he continued with ardor after his departure to the university of Edinburgh, where he took his medical degree VOL. III.-20

in 1754. It had formerly been supposed that quicklime held in absorption some igneous particles or something of an igneous character, but the investigations of Black led him to the discovery that the causticity of the calcareous earths was not derived from any combination, but was their peculiar property, and that they lost this property when they combine with a certain portion of air, to which he gave the name of fixed air, but which is now known as carbonic acid gas. This discovery, which forms an era in the history of chemistry, and opened the way for the experiments of Priestley, Cavendish, and Lavoisier, was stated and explained by Black in his dissertation when he received his medical degree. Dr. Black was invited in 1756 to succeed Dr. Cullen at Glasgow, the latter having removed to Edinburgh, and in this position he made his second and most important discovery. Ice, he observed, being converted into water, absorbs a large amount of heat, the existence of which is no longer indicated by the thermometer. Water being converted into vapor absorbs another large amount of heat, which is in like manner lost to the senses or the thermometer. To change a solid into a fluid, or a fluid into a gas, a quantity of heat has to lose its existence, as it were, in the newly created state of the body. On the other hand, heat is given out when a gas is liquefied, or a liquid solidified; that is, the heat which was apparently lost when the solid was made a liquid, becomes sensible again when the liquid is made a solid; and the same is true, also, of the change from a gas to a fluid. Thus a freezing process is always a warming process to the things which are nearest it, because the heat which was lost in the fluid is let loose when the solid is formed. On the other hand, a melting process is always a cooling process to the things in the neighborhood, because to melt a substance a large amount of heat has to be sacrificed, and this heat is abstracted from the nearest bodies. Thus, on a sunny spring day in the north, when the snow is melting, there is always a raw chill in the air, because the heat is constantly taken out of the air to change the snow into water, and becomes insensible in the latter. Dr. Black, observing these phenomena, said that the heat is concealed (latet) in the water and vapor, and introduced the name and the theory of latent heat. This discovery suggested to Watt, who was a pupil of Black, his improvements in the steam engine. In 1766, Dr. Black was again made the successor of Dr. Cullen, being appointed to the chemical chair of the university of Edinburgh. Impressed with his responsibility as a lecturer before the large concourse of students who frequented that university, he made no further investigations, devoting himself exclusively to the preparation of his lectures, and so great was his success that he made chemistry a fashionable study at Edinburgh, and a branch of a polite education. Ilis lectures were resorted to by the gentlemen of the capital and

by men of science from all parts of Europe. It is a curious fact that Dr. Black, having given up experimenting for lecturing, combated for several years results which other chemists had legitimately founded upon his own discoveries. A feeble constitution obliged him to husband his strength in his later years, and, unable to develop his views with the completeness and nicety which he desired, he desisted at length from any attempts at composition, and various continental chemists put forth in their own names the ideas which they had received in the lecture-room of Dr. Black. His only publications were 3 dissertations, giving an account of his experiments on magnesia, quicklime, and other alkaline substances; his observations on the more ready freezing of water that has been boiled; and his analysis of some boiling springs in Iceland. His death occurred while he was sitting at table, and so gently that he did not drop the glass of milk which he held at the moment in his hand, but rested it upon his knee, and was, at first, thought to have fallen asleep.

BLACK ASSIZE, a judicial sitting of the courts held at Oxford in 1577, and rendered historical by the pestilential and deadly fever which was introduced into the court from the, gaol, and swept away judges, jurymen, and counsel, and extended itself into the town and neighborhood. The superstitions of the age invested it with a special character, and it was remarked that no women nor poor people died of it.

BLACK BAND, the name given by Mushet to certain layers of argillaceous carbonate of iron of the coal formation found near Airdrie, E. of Glasgow, as also in other parts of Scotland, and in Wales, and which, until he called attention to them, had escaped notice. They are of the common variety of this ore, only of a darker color than usual, and in blocks of pretty regular thickness. The great extent and convenient access of the beds in Scotland, together with their occurrence near beds of coal and limestone, have given to this ore an importance due neither to its percentage of iron nor to the quality of the metal it produces. It may be also that its value is somewhat enhanced by the mixture of bituminous and coaly matters, which renders a less amount of fuel necessary to produce the iron. A rich specimen of it, of specific gravity 3.0533, analyzed by Dr. Colquhoun, gave per cent. carbonic acid, 35.17; protoxide of iron, 53.03; lime, 3.33; magnesia, 1.77; silica, 1.4; alumina, 0.63; peroxide of iron, 0.23; carbonaceous or bituminous matter, 3.03; moisture and loss, 1.41. Its percentage of metallic iron is 41.25.

BLACK COPPER, the crude metal produced by the first smelting of copper ores, and which requires subsequent melting and refining to convert it into merchantable copper. It is sometimes conveniently and rudely prepared in cheap furnaces near the copper mines, as the easiest method of concentrating the metallic portions of the ore and reducing the cost of transporta

tion to distant markets. It generally contains from 70 to 95 per cent. of copper, mechanically mixed with metallic iron and a small proportion of other foreign matters.

BLACK DEATH. See PLAGUE.

BLACK FEET, a powerful Indian tribe at the foot of the Rocky mountains, and between the Yellowstone river and the Missouri. They are one of the most powerful and formidable tribes in the western territory, and, until recently, have given much trouble to the government, which, on more than one occasion, has found it necessary to send troops to overawe them. Against them the famous expedition to the Yellowstone, in 1826 and 1827, under command of Gen. Atkinson, was directed. They are said to number about 10,000 warriors, but as they receive no annuities from the government but little care has been taken to obtain a correct census. They are great robbers and depredators, and furnish large quantities of furs, &c., to the American traders, who have a station on the Yellowstone at the falls. They seem to have more affinity in language and customs with the tribes west than east of the Rocky mountains.

BLACK FLUX, a mixture of carbonate of potash and carbon in a state of the finest division. It is prepared by intimately mixing 1 part of nitre with 2 to 3 parts of crude tartar or cream of tartar, and deflagrating the mixture by dropping ignited charcoal into it. When the chemical action has ceased, the black product is ground in a mortar, passed through a fine hair-sieve, and then put away for use. It must, from its property of deliquescing on exposure to the air, be kept in well-stopped bottles. It is employed as a flux in reducing ores of metals, particularly of lead and copper; and it has the properties both of the reducing and of the desulphurizing fluxes. See FLUX.

BLACK FOREST, the south-western extremity of the ancient Hercynian forest, called by the Romans Sylva Martiana, and which received during the middle ages the name of Schwartzwald or Black Forest. It is a range of woody mountains in the south-western part of Germany, traversing the territories of Baden and Würtemberg, and forming the eastern boundary of the basin of the Rhine. It extends 85 miles in length, alınost parallel with the course of the Rhine, from which it is distant in many places not more than 20 miles, and has a breadth in its southern part of about 30 miles, and in its northern part of about 18. The Black Forest consists rather of elevated plains or tableland, than of insulated mountains, and describes itself upon the horizon in regular undulating lines without any of those sudden peaks and notches which mark the summits of the Alps and Pyrénées. Its greatest elevation is near and to the east of Freiburg, in the region where the Wiesen takes its rise, and where is the famous defile called Hell, a narrow valley surrounded by lofty mountains, and celebrated in the retreat of Moreau in 1796. The highest summits, the Feldberg, the Belchenberg, and

the Kandel, are between 4,000 and 5,000 feet above the level of the sea. The descent of the Black Forest toward the Rhine is very abrupt, causing the rivers which take their rise on this side, the Murg, Kinzig, and Eltz, to swell gradually during the rains, and to merit, until their union with the Rhine, the name of capricious torrents. The eastern slope is very gentle, and gives rise to the Neckar and the Danube, the former soon changing its direction to the north and west, and joining the Rhine, the latter receiving numerous tributaries from the Alpine systems as it continues its course to the east. The Black Forest is composed mainly of granite, though the surface is in some places covered with sandstone, and gneiss appears around its base. On some of the heights porphyry is found, and there are many mines of silver, copper, iron, lead, and cobalt. Its mineral waters too, especially those of Baden and Wildbad, have a European celebrity. The summits of the Black Forest are during 8 months of the year covered with snow; they are generally destitute of trees, and except during the greatest heats of summer display no verdure. Descending from the top, the first trees that appear are the pine, the beach, and the maple, which are succeeded by the dense forests of fir with which all the middle and lower parts of the mountains are covered. These firs make the timber of ships for navigating the Rhine, and also furnish those forests of masts which fill all the great ports of Europe. Here, near the foot of the mountains, are many picturesque valleys, of which that of the Murg, situated near the thermal waters of Baden, is particularly distinguished for its natural beauty. Villages and hamlets are interspersed, and the inhabitants are mainly engaged in rearing live stock, trading in timber, and in the manufacture of numerous toys, which are spread over the world for the amusement of the youthful generation. The most famous of these is the wooden clock, of which it is estimated that the number of 180,000 are annually distributed through Europe and America. Agriculture is there of little importance, the soil being unfruitful and the climate severe, yet the valleys produce excellent fruits.-The middle and more recent ages have left traces of their history on the whole range of the Black Forest. Abbeys and castles stand in decay, the monuments of a past greatness, and pious and poetic legends hover about their ruins. There is the castle of Geroldseck, founded, if tradition be true, by the brother of Charlemagne; the castle of Stauffenburg, once occupied by a bold knight, the lover of an Undine or water-spirit; the 2 castles of Baden, one in ruins, transformed into a park and made open to all, the other near by, built over a dungeon in which the Vehmic tribunal used to meet; the castle of Yberg, ill-famed in the mouths of the people, because an impious and rapacious knight had there exhumed the bones of one of his ancestors to find treasure; and the castle of Rocteln, in the vale of Wiesen,

the abode of Hebel, the German song writer. These traditional attractions, joined to its beautiful scenery and its mineral waters, make the Black Forest, despite its unpropitious name, a most interesting locality. The peculiar industry and simplicity of the inhabitants, some of them constructing children's playthings in cottages, some guiding rafts of timber down the mountain torrents, give an additional interest. Agreeable sketches of home-life in the Black Forest may be found in the tales of Berthold Auerbach.

BLACK GUM, the arbitrary name of a tree without gum, a species of nyssa or tupelo of Adanson, which is the only genus of Endlicher's suborder nyssacea of his order santalaceœ. Linnæus had it in polygamia diacia; Elliott placed it in diacia pentandria, and Darlington in pentandria monogynia. The black gum is the N. multiflora, and is known in New England as snag-tree and hornpipe; in New York as pepperidge, and as the gum-tree in the middle states. It thrives in low, clayey soil, and in dense forests grows to 40 feet high. Its external habits are various, and it is often confounded with other trees. It has very many branches, which are often crooked; a dense pyramidal head; leaves 1 to 5 inches long, and of a lustrous green, in tufts of 4 or more at the ends of the branches; greenish flowers in clusters, ripening to blue-black; mouse-colored bark in longitudinal furrows; wood close and tough, resists splitting, though it decays sooner in the weather than that of the elm. The wood is used for water-pipes in the salt works at Syracuse; it is also good for hatters' blocks, wheel naves, and oog-wheels. The tree is very vigorous; it was introduced into Europe as an ornamental tree in 1739; it thrives in the south of England, and even in Hanover.

BLACK HAWK, a N. E. central county of Iowa, with an area of 576 sq. miles, divided by Cedar river into nearly equal parts. The surface is occupied mainly by prairies, though portions of it are well wooded. The productions of the county in 1856 amounted to 217,168 bushels of Indian corn, 26,821 of wheat, 2,365 tons of hay, 36,567 lbs. of butter, and 5,904 lbs. of cheese. Pop. 5.538.

BLACK HILLS, the name given to a mountain range of Missouri territory. Commencing near the Missouri river, in lat. 47° N. and long. 103° W., it stretches along this meridian to about 43° N. lat., after which it suddenly changes its course to the west, and is finally lost among the Rocky mountains. On the W. side of this range are the tributaries of the Yellowstone river; on the E. and S. the affluents of the Missouri and the Platte. Laramie Peak is the highest known summit; it has an elevation of 8,000 feet above the sea. Recent explorations have shown the Black Hills to be inuch nearer the Missouri river than was formerly supposed.

BLACK HOLE, a small close dungeon in Fort William, Calcutta, which will long be re

membered as the scene of one of the most tragical events in the history of British India. On the capture of Calcutta by Surajah Dowlah, June 20, 1756, the British garrison, consisting of 146 men, under the command of Mr. Holwell, were taken prisoners and locked up for the night in the common dungeon of the fortress, a strongly barred room, 18 feet square, and never intended for the confinement of more than 2 or 3 men at a time. There were only 2 windows, both opening toward the west, whence, under the best of circumstances, but little air could enter. Add to this that a projecting verandah outside, and thick iron bars within, materially impeded what little ventilation there might be, while conflagrations raging in different parts of the fort gave the atmosphere an oppressiveness unusual even in that sultry climate, and we may form a faint idea of the sufferings of these unhappy creatures, exhausted with previous fatigue, and packed so tightly in their prison that it was with difficulty the door could be closed. A few moments sufficed to throw them into a profuse perspiration, the natural consequence of which was a raging thirst. They stripped off their clothes to gain more room, sat down on the floor that the air might circulate more freely, and, when every expedient failed, sought by the bitterest insults to provoke the guards to fire on them. One of the soldiers stationed in the verandah was offered 1,000 rupees to have them removed to a larger room. He went away, but returned saying it was impossible. The bribe was then doubled, and he made a second attempt with a like result; the nabob was asleep, and no one durst wake him. By 9 o'clock several had died, and many more were delirious. A frantic cry for water now became general, and one of the guards, more compassionate than his fellows, caused some to be brought to the bars, where Mr. Holwell and 2 or 3 others received it in their hats, and passed it on to the men behind. In their impatienco to secure it nearly all was spilt, and the little they drank seemed only to increase their thirst. Self-control was soon lost; those in remote parts of the room struggled to reach the window, and a fearful tumult ensued, in which the weakest were trampled or pressed to death. They raved, fought, prayed, blasphemed, and many then fell exhausted on the floor, where suffocation put an end to their torments. The Indian soldiers, meanwhile, crowded around the windows, and even brought lights that they might entertain themselves with the dreadful spectacle. The odor which filled the dungeon became more deadly every moment, and about 11 o'clock the prisoners began to drop off fast. At length, at 6 in the morning, Surajah Dowlah awoke, and ordered the door to be opened. Of the 146 only 23, including Mr. Holwell (from whose narrative, published in the Annual Register for 1758, our account of this event is partly derived), remained alive, and they were either stupefied or raving. Fresh air soon re

vived them, and the commander was then taken before the nabob, who expressed no regret for what had occurred, and gave no other sign of sympathy than ordering the Englishman a chair and a glass of water. Notwithstanding this indifference, Mr. Holwell and some others acquit him of any intention of causing the catastrophe, and ascribe it to the malice of certain inferior officers, but many think this opinion unfounded. Holwell and 3 others were sent prisoners to Muxadavad; the rest of the survivors obtained their liberty, and the dead bodies were carelessly thrown into a ditch. The Black Hole is now used as a warehouse, and an obelisk, 50 feet high, erected in memory of the victims, stands before the gate. It was struck by lightning some years ago, and has since been gradually falling to ruin.

BLACK JACK, a term loosely applied by miners to blende, the sulphuret of zinc, or to any other ore which resembles it in being obnoxious to them, if in no other respect.-It is also the name commonly given in the southern states to a small species of oak tree (quercus stellata), also called post-oak, for its being, when full grown, of a convenient size for making posts.

BLACK LEAD, an incorrect name for GRAPHITE, which see. It contains no lead, and has no relations with lead ore.

BLACK LETTER, a term applied to the old English or modern Gothic letter, in which the early manuscripts were written, and the first English books were printed.

BLACK MAIL, a tribute formerly paid by the occupants of lands in the northern counties of England to some Scottish chieftain for protection against the depredations of border rievers or moss troopers. By the terms of the arrangement the borderer receiving this tribute was bound not merely to abstain from injury to the person paying it, but also to recover his property if taken by others-hence it has been called protection rent. (See Scott's introduction to "Border Minstrelsy.") At a later period, after civil order had been established in the border counties, and agriculture and peaceful habits prevailed in the lowlands of Scotland, the custom of paying black mail to the highland chiefs by the lowland farmers became common, and continued till within a century. Some incidents of this custom are related in 2 of Scott's novels, "Waverley" and "Rob Roy." The origin of the term seems to be this: mail in the old Scottish law was used for rent of an estate. It seems to have been the name of a small coin in England and Scotland. Black mails may be considered therefore as equivalent to black rents, which were payable in kind, that is, what was produced by the estate; being the same as the reditus nigri, in contradistinction to the reditus albi, which were payable in silver.-The modern sense of the phrase is mainly derived from the fact that such rent was paid to robbers and thieves as the price of immunity; hence now used for money paid under any extortion, especially when the injury sought to be guarded

against is one for which there is no adequate protection by law. It generally implies a corrupt speculation out of some advantage which it is unconscionable to use. It is also sometimes used for money paid to prevent an exposure of some wrong doing, being in this sense what is called hush money.

BLACK MOUNTAINS, the culminating group of the Appalachian system, already referred to in the article APPALACHIAN MOUNTAINS, named from the dark growth of balsam-firs and other evergreens which cover their summits. Their position is in Yancey and Buncombe counties, North Carolina, between the main central ridges on the west and a portion of the Blue Ridge on the east. Unlike the other ridges of the Alleghanies, they lie for the most part transverse to the general trend of the range, and give this direction to the great valleys and rivers included between them. They rise from a district of great elevation, the height of the valley at Asheville, on the French Broad river, being about 2,000 feet above the sea, and that of Toe river, at Burnsville, Yancey county, about 2,500 feet. From this plateau the drainage is toward the Ohio in a northerly direction by the branches of the Great Kanawha, by those of the Holston and the French Broad toward the south-west, and by those of the Yadkin and the Catawba into the Pedee and Santee toward the south-east. This posi tion at the sources of streams flowing in such diverse directions, long since pointed out this district as probably the most elevated east of the Rocky mountains. The distinguished botanists, Michaux, father and son, were led to the same opinion by their observations upon the northern character of the forest growth with which these mountains are covered. In 1835, the first attempts to determine the elevation of the greatest heights were made by Dr. E. Mitchell, late professor at the university of North Carolina at Chapel Hill. The principal peak, which is known in North Carolina as Mount Mitchell, he estimated, according to the statements of his friends, by barometrical observations, to be 6,476 feet above the sea, calculating Morgantown, his base, to be 968 feet above tide. The late railroad surveys give this point an elevation of 1,169 feet, or of that where his stationary barometer hung about 1,200 feet, which would make the height of the peak about 6,700 feet. In 1844 he visited the locality again, and calculating from a base of more uncertain elevation at Asheville, he made the height 6,672 feet. In 1855, the Hon. T. L. Clingman of North Carolina made the elevation 6,941 feet, and in 1856 Prof. Guyot determined the highest point, which, as stated in the article APPALACHIAN MOUNTAINS, he then called the Black Dome, to be 6,760 feet high. The following are the elevations and names of the 12 highest points, all of which are higher than Mount Washington in New Hampshire, as published in 1857 from the investigations of Professor Guyot:

The summit of Mt. Washington is 6,285 feet above the level of the sea. In 1857 Dr. Mitchell made a third excursion to these mountains, for the purpose of establishing his claim. to having first measured the elevation of the highest summit, the honor of which was also claimed by the Hon. Mr. Clingman. He went well provided with several of Green's barometers, recommended by the Smithsonian institution, intending not only to make exact measurements of the highest point, but also, at the same time, to test in this latitude the formula adopted for barometrical observations. Before he had fixed, however, upon a series of points by the spirit level, preparatory to the observations with the barometer, the sad accident occurred by which he lost his life, as he was traversing alone one of the mountain ravines. His name is thus still more intimately associated with these high summits, by which one of them will long continue to be known.

BLACK RIVER, of New York, rises in Herkimer co., and after passing through Oneida and Lewis counties, changes its course at a place called Great Bend, passes by Watertown, and flows through Black River bay into Lake Ontario. Near Turin, in Lewis co., it has a fall of about 63 feet. Below the fall, it is navigable to Carthage, a distance of 40 miles. From Carthage to Watertown is a series of rapids, rendering navigation almost impossible. A canal has been opened, however, from the Upper falls to Rome on the Erie canal. The whole length of the river is 125 miles, and its breadth at Watertown (6 m. from its mouth) is 60 yards.-BLACK RIVER, or Big Black river, of Missouri and Arkansas, is the largest affluent of White river. It rises in the S. E. part of the former state, takes a southerly course, enters Arkansas, and joins the White river 40 miles below Batesville. During 9 months of the year it is navigable for a distance of 100 miles from its mouth. Its entire length is about 400 miles. Trout and other excellent fish are caught in its waters in great abundance.

BLACK ROD, the usher to the order of the garter, so called from the black rod which he carries at the feast of St. George, when the order annually assembles. He also notifies the election of new knights, carries the garter to foreign princes and others, and is the principal officer of the college of arms, and chief of the heralds.

BLACK SEA (anc. Pontus Euxinus), an inland sea, on the border between Asia and Europe, bounded by Turkey, Russia in Europe, and the Caucasian provinces, and connected with the Mediterranean through the straits of