Part 8
Boron hydride has probably never been isolated in the pure condition; on heating boron trioxide with magnesium filings, a magnesium boride Mg3B2 is obtained, and if this be decomposed with dilute hydrochloric acid a very evil-smelling gas, consisting of a mixture of hydrogen and boron hydride, is obtained. This mixture burns with a green flame forming boron trioxide; whilst boron is deposited on passing the gas mixture through a hot tube, or on depressing a cold surface in the gas flame. By cooling it with liquid air Sir W. Ramsay and H.S. Hatfield obtained from it a gas of composition B3H3. The mixture probably contained also some BH3 (W. Ramsay and H.S. Hatfield, _Proc. Chem. Soc._, 17, p. 152). Boron fluoride BF3 was first prepared in 1808 by Gay Lussac and L. Thenard and is best obtained by heating a mixture of the trioxide and fluorspar with concentrated sulphuric acid. It is a colourless pungent gas which is exceedingly soluble in water. It fumes strongly in air, and does not attack glass. It rapidly absorbs the elements of water wherever possible, so that a strip of paper plunged into the gas is rapidly charred. It does not burn, neither does it support combustion. A saturated solution of the gas, in water, is a colourless, oily, strongly fuming liquid which after a time decomposes, with separation of metaboric acid, leaving hydrofluoboric acid HF.BF3 in solution. This acid cannot be isolated in the free condition, but many of its salts are known. Boron fluoride also combines with ammonia gas, equal volumes of the two gases giving a white crystalline solid of composition BF3.NH3; with excess of ammonia gas, colourless liquids BF3.2NH3 and BF3.3NH3 are produced, which on heating lose ammonia and are converted into the solid form.
Boron chloride BCl3 results when amorphous boron is heated in chlorine gas, or more readily, on passing a stream of chlorine over a heated mixture of boron trioxide and charcoal, the volatile product being condensed in a tube surrounded by a freezing mixture. It is a colourless fuming liquid boiling at 17-18 deg. C, and is readily decomposed by water with formation of boric and hydrochloric acids. It unites readily with ammonia gas forming a white crystalline solid of composition 2BCl3.3NH3.
Boron bromide BBr3 can be formed by direct union of the two elements, but is best obtained by the method used for the preparation of the chloride. It is a colourless fuming liquid boiling at 90.5 deg. C. With water and with ammonia it undergoes the same reactions as the chloride. Boron and iodine do not combine directly, but gaseous hydriodic acid reacts with amorphous boron to form the iodide, BI3, which can also be obtained by passing boron chloride and hydriodic acid through a red-hot porcelain tube. It is a white crystalline solid of melting point 43 C.; it boils at 210 deg. C., and it can be distilled without decomposition. It is decomposed by water, and with a solution of yellow phosphorus in carbon bisulphide it gives a red powder of composition PBI2, which sublimes _in vacuo_ at 210 deg. C. to red crystals, and when heated in a current of hydrogen loses its iodine and leaves a residue of boron phosphide PB.
Boron nitride BN is formed when boron is burned either in air or in nitrogen, but can be obtained more readily by heating to redness in a platinum crucible a mixture of one part of anhydrous borax with two parts of dry ammonium chloride. After fusion, the melt is well washed with dilute hydrochloric acid and then with water, the nitride remaining as a white powder. It can also be prepared by heating borimide B2(NH)3; or by heating boron trioxide with a metallic cyanide. It is insoluble in water and unaffected by most reagents, but when heated in a current of steam or boiled for some time with a caustic alkali, slowly decomposes with evolution of ammonia and the formation of boron trioxide or an alkaline borate; it dissolves slowly in hydrofluoric acid.
Borimide B2(NH)3 is obtained on long heating of the compound B2S3.6NH2 in a stream of hydrogen, or ammonia gas at 115-120 deg. C. It is a white solid which decomposes on heating into boron nitride and ammonia. Long-continued heating with water also decomposes it slowly.
Boron sulphide B2S3 can be obtained by the direct union of the two elements at a white heat or from the tri-iodide and sulphur at 440 deg. C., but is most conveniently prepared by heating a mixture of the trioxide and carbon in a stream of carbon bisulphide vapour. It forms slightly coloured small crystals possessing a strong disagreeable smell, and is rapidly decomposed by water with the formation of boric acid and sulphuretted hydrogen. A pentasulphide B2S5 is prepared, in an impure condition, by heating a solution of sulphur in carbon bisulphide with boron iodide, and forms a white crystalline powder which decomposes under the influence of water into sulphur, sulphuretted hydrogen and boric acid.
Boron trioxide B2O3 is the only known oxide of boron; and may be prepared by heating amorphous boron in oxygen, or better, by strongly igniting boric acid. After fusion the mass solidifies to a transparent vitreous solid which dissolves readily in water to form boric acid (q.v.); it is exceedingly hygroscopic and even on standing in moist air becomes opaque through absorption of water and formation of boric acid. Its specific gravity is 1.83 (J. Dumas). It is not volatile below a white heat, and consequently, if heated with salts of more volatile acids, it expels the acid forming oxide from such salts; for example, if potassium sulphate be heated with boron trioxide, sulphur trioxide is liberated and potassium borate formed. It also possesses the power of combining with most metallic oxides at high temperatures, forming borates, which in many cases show characteristic colours. Many organic compounds of boron are known; thus, from the
## action of the trichloride on ethyl alcohol or on methyl alcohol, ethyl
borate B(OC2H5)3 and methyl borate B(OCH3)3 are obtained. These are colourless liquids boiling at 119 deg. C. and 72 deg. C. respectively, and both are readily decomposed by water. By the action of zinc methyl on ethyl borate, in the requisite proportions, boron trimethyl is obtained, thus:--2B(OC2H5)2 + 6Zn(CH3)2 = 2B(CH3)3 +
/ CH3 + 6Zn < \ OC2H5
as a colourless spontaneously inflammable gas of unbearable smell. Boron triethyl B(C2H5)3 is obtained in the same manner, by using zinc ethyl. It is a colourless spontaneously inflammable liquid of boiling point 95 deg. C. By the action of one molecule of ethyl borate on two molecules of zinc ethyl, the compound B(C2H5)2.OC2H5 diethylboron ethoxide is obtained as a colourless liquid boiling at 102 deg. C. By the action of water it is converted into B(C2H5)2.OH, and this latter compound on exposure to air takes up oxygen slowly, forming the compound B.C2H5.OC2H5.OH, which, with water, gives B(C2H5).(OH)2. From the condensation of two molecules of ethyl borate with one molecule of zinc ethyl the compound B2.C2H5.(OC2H5)5 is obtained as a colourless liquid of boiling point. 112 deg. C. Boron triethyl and boron trimethyl both combine with ammonia.
The atomic weight of boron has been determined by estimating the water content of pure borax (J. Berzelius), also by conversion of anhydrous borax into sodium chloride (W. Ramsay and E. Aston) and from analysis of the bromide and chloride (Sainte-Claire Deville); the values obtained ranging from 10.73 to 11.04. Boron can be estimated by precipitation as potassium fluoborate, which is insoluble in a mixture of potassium acetate and alcohol. For this purpose only boric acid or its potassium salt must be present; and to ensure this, the borate can be distilled with sulphuric acid and methyl alcohol and the volatile ester absorbed in potash.
BOROUGH [BURROUGH, BURROWE, BORROWS], STEVEN (1525-1584), English navigator, was born at Northam in Devonshire on the 25th of September 1525. In 1553 he took part in the expedition which was despatched from the Thames under Sir Hugh Willoughby to look for a northern passage to Cathay and India, serving as master of the "Edward Bonaventure," on which Richard Chancellor sailed as pilot in chief. Separated by a storm from the "Bona Esperanza" and the "Bona Confidentia," the other two ships of the expedition, Borough proceeded on his voyage alone, and sailing into the White Sea, in the words of his epitaph, "discouered Moscouia by the Northerne sea passage to St Nicholas" (Archangel). In a second expedition, made in the "Serchthrift" in 1556, he discovered Kara Strait, between Novaya Zemlya and Vaygach island. In 1560 he was in charge of another expedition to Russia, and, probably in 1558, he also made a voyage to Spain. At the beginning of 1563 he was appointed chief pilot and one of the four masters of the queen's ships in the Medway, and in this office he spent the rest of his life. He died on the 12th of July 1584, and was buried at Chatham. His son, Christopher Borough, wrote a description of a trading expedition made in 1579-1581 from the White Sea to the Caspian and back.
His younger brother, WILLIAM BOROUGH, born in 1536, also at Northam, served as an ordinary seaman in the "Edward Bonaventure" on her voyage to Russia in 1553, and subsequently made many voyages to St Nicholas. Later he transferred his services from the merchant adventurers to the crown. As commander of the "Lion" he accompanied Sir Francis Drake in his Cadiz expedition of 1587, but he got himself into trouble by presuming to disagree with his chief concerning the wisdom of the attack on Lagos. He died in 1599. He was the author of _A Discourse of the Variation of the Compas, or Magneticall Needle_ (1581), and some of the charts he made are preserved at the British Museum and Hatfield.
BOROUGH (A.S. nominative _burh_, dative _byrig_, which produces some of the place-names ending in _bury_, a sheltered or fortified place, the camp of refuge of a tribe, the stronghold of a chieftain; of. Ger. _Burg_, Fr. _bor_, _borc_, _bourg_), the term for a town, considered as a unit of local government.
_History of the English Borough._--After the early English settlement, when Roman fortifications ceased to shelter hostile nations, their colonies and camps were used by the Anglo-Saxon invaders to form tribal strongholds; nevertheless burhs on the sites of Roman colonies show no continuity with Roman municipal organization. The resettlement of the Roman Durovernum as the burh of the men of (East) Kent, under a changed name, the name "burh of the men of Kent," Cant-wara-byrig (Canterbury), illustrates this point. The burh of the men of West Kent was Hrofesceaster (Durobrivae), Rochester, and many other _ceasters_ mark the existence of a Roman camp occupied by an early English burh. The tribal burh was protected by an earthen wall, and a general obligation to build and maintain burhs at the royal command was enforced by Anglo-Saxon law. Offences in disturbance of the peace of the burh were punished by higher fines than breaches of the peace of the "ham" or ordinary dwelling. The burh was the home of the king as well as the asylum of the tribe, and there is reason to think that the boundary of the borough was annually sanctified by a religious ceremony, and hence the long retention of a processional perambulation. Possibly the "hedge" or "wall" of the borough gave it, besides safety, a sanctity analogous to that enjoyed by the Germanic assembly while gathered within its "hedge," which the priests solemnly set up when the assembly gathered, and removed when it was over. While the "peace" of the Germanic assembly was essentially temporary, the "peace" of the burh was sacred all the year round. Its "hedge" was never removed. The sanctity of the burh was enjoyed by all the dwellings of the king, at first perhaps only during his term of residence. Neither in the early English language nor in the contemporary Latin was there any fixed usage differentiating the various words descriptive of the several forms of human settlement, and the tribal refuges cannot accordingly be clearly distinguished from villages or the strongholds of individuals by any purely nomenclative test. It is not till after the Danish invasions that it becomes easier to draw a distinction between the burhs that served as military strongholds for national defence and the royal vills which served no such purpose. Some of the royal vills eventually entered the class of boroughs, but by another route, and for the present the private stronghold and the royal dwelling may be neglected. It was the public stronghold and the administrative centre of a dependent district which was the source of the main features peculiar to the borough.
Many causes tended to create peculiar conditions in the boroughs built for national defence. They were placed where artificial defence was most needed, at the junction of roads, in the plains, on the rivers, at the centres naturally marked out for trade, seldom where hills or marshes formed a sufficient natural defence. The burhs drew commerce by every channel; the camp and the palace, the administrative centre, the ecclesiastical centre (for the mother-church of the state was placed in its chief burh), all looked to the market for their maintenance. The burh was provided by law with a mint and royal moneyers and exchangers, with an authorized scale for weights and measures. Mercantile transactions in the burhs or _ports_, as they were called when their commercial rather than their military importance was accentuated, were placed by law under special legal privileges in order no doubt to secure the king's hold upon his toll. Over the burh or port was set a reeve, a royal officer answerable to the king for his dues from the burh, his rents for lands and houses, his customs on commerce, his share of the profits from judicial fines. At least from the 10th century the burh had a "moot" or court, the relation of which to the other courts is matter of speculation. A law of Edgar, about 960, required that it should meet three times a year, these being in all likelihood assemblies at which attendance was compulsory on all tenants of the burghal district, when pleas concerning life and liberty and land were held, and men were compelled to find pledges answerable for their good conduct. At these great meetings the borough reeve (_gerefa_) presided, declaring the law and guiding the judgments given by the suitors of the court. The reeve was supported by a group of assistants, called in Devon the "witan," in the boroughs of the Danelaw by a group of (generally twelve) "lawmen," in other towns probably by a group of aldermen, senior burgesses, with military and police authority, whose office was in some cases hereditary. These persons assisted the reeve at the great meetings of the full court, and sat with him as judges at the subordinate meetings which were held to settle the unfinished causes and minor causes. There was no compulsion on those not specially summoned to attend these extra meetings. At these subordinate jurisdictional assemblies, held in public, and acting by the same authority as the annual gathering of all the _burh-wara_, other business concerning borough administration was decided, at least in later days, and it is to these assemblies that the origin of the town council may in many cases be ascribed. In the larger towns the division into wards, with a separate police system, can be traced at an early time, appearing as a unit of military organization, answerable for the defence of a gate of the town. The police system of London is described in detail in a record of 930-940. Here the free people were grouped in associations of ten, each under the superintendence of a headman. The bishops and reeves who belonged to the "court of London" appear as the directors of the system, and in them we may see the aldermen of the wards of a later time. The use of the word _bertha_ for ward at Canterbury, and the fact that the London wardmoot at a later time was used for the frankpledge system as well as for the organization of the muster, point to a connexion between the military and the police systems in the towns. At the end of the 9th and beginning of the 10th century there is evidence of a systematic "timbering" of new burhs, with the object of providing strongholds for the defence of Wessex against the Danes, and it appears that the surrounding districts were charged with their maintenance. In charters of this period a "haw," or enclosed area within a burh, was often conveyed by charter as if it were an apanage of the lands in the neighbourhood with which it was conveyed; the Norman settlers who succeeded to lands in the county succeeded therewith to houses in the burhs, for a close association existed between the "thegns" of the shire and the shirestow, an association partly perhaps of duty and also of privilege. The king granted borough "haws" as places of refuge in Kent, and in London he gave them with commercial privileges to his bishops. What has been called the "heterogeneous" tenure of the shirestow, one of the most conspicuous characteristics of that particular type of borough, was further increased by the liberty which some burgesses enjoyed to "commend" themselves to a lord of their own choosing, promising to that lord suit and service and perhaps rent in return for protection. Over these burgesses the lords could claim jurisdictional rights, and these were in some cases increased by royal grants of special rights within certain "sokes." The great boroughs were honeycombed with sokes, or areas of seignorial jurisdiction, within which the royal reeve's authority was greatly restricted while that of the lord's reeve took precedence. Even the haws, being "burhs" or strongholds within a stronghold, enjoyed a local "peace" which protected from official intrusion. Besides heterogeneity of tenure and jurisdiction in the borough, there was also heterogeneity of status; there were burh-thegns and cnihts, mercatores, burgesses of various kinds, the three groups representing perhaps military, commercial and agricultural elements. The burh generally shows signs of having been originally a village settlement, surrounded by open fields, of which the borough boundary before 1835 will suggest the outline. This area was as a rule eventually the area of borough jurisdiction. There is some evidence pointing to the fact that the restriction of the borough authority to this area is not ancient, but due to the Norman settlement. The wide districts over which the boroughs had had authority were placed under the control of the Norman castle which was itself built by means of the old English levy of "burh-work." The borough court was allowed to continue its work only within its own immediate territory, and, to prevent conflict, the castle was placed outside the borough. Losing their place in the national scheme of defence, the burgess "cnihts" made commerce their principal object under the encouragement of the old privileges of the walled place.
Besides the great co-operative strongholds in which many lords had burgesses, there were small boroughs held by a single lord. In many cases boroughs of this "seignorial" type were created upon the royal estates. Out of the king's vill, as a rule the jurisdictional centre of a hundred, there was sometimes created a borough. The lines of division before Domesday Book are obscure, but it is probable that in some cases, by a royal grant of jurisdiction, the inhabitants of a populous royal vill, where a hundred court for the district was already held, were authorized to establish a permanent court, for the settlement of their disputes, distinct from the hundred court of the district. Boroughs of this type with a uniform tenure were created not only on the king's estates but also on those of his tenants-in-chief, and in 1086 they were probably already numerous. A borough was usually, though perhaps not invariably, the companion of a Norman castle. In some cases a French "bourg" was created by the side of an English borough, and the two remained for many generations distinct in their laws and customs: in other cases a French "bourg" was settled by the side of an English village. A large number of the followers of the Norman lords had been almost certainly town-dwellers in their own country, and lost none of their burghal privileges by the migration. Every castle needed for its maintenance a group of skilled artisans, and the lords wished to draw to the castle gates all kinds of commodities for the castle's provision. The strength of the garrison made the neighbourhood of the castle a place of danger to men unprotected by legal privilege; and in order to invite to its neighbourhood desirable settlers, legal privileges similar to those enjoyed in Norman or English boroughs were guaranteed to those who would build on the plots which were offered to colonists. A low fixed rental, release from the renders required of villeins, release from the jurisdiction of the castle, and the creation of a separate borough jurisdiction, with or without the right to choose their own officers, rules fixing the maximum of fees and fines, or promising assessment of the fines by the burgesses themselves, the cancelling of all the castellan's rights, especially the right to take a forced levy of food for the castle from all within the area of his jurisdiction, freedom from arbitrary tallage, freedom of movement, the right to alienate property and devise land, these and many other privileges named in the early seignorial charters were what constituted the Norman _liber burgus_ of the seignorial type. Not all these privileges were enjoyed by all boroughs; some very meagre releases of seignorial rights accompanied the lord's charter which created a borough and made burgesses out of villeins. However liberal the grant, the lord or his reeve still remained in close personal relation with the burgesses of such places, and this character, together with the uniformity of their tenure, continued to hold them apart from the boroughs of the old English type, where all varieties of personal relationship between the lords and their groups of tenants might subsist. The royal charters granting the right to retain old customs prevented the systematic introduction into the old boroughs of some of the incidents of feudalism. Rights of the king took precedence of those of the lord, and devise with the king's consent was legal. By these means the lords' position was weakened, and other seignorial claims were later evaded or contested. The rights which the lords failed to keep were divided between the king and the municipality; in London, for instance, the king obtained all escheats, while the borough court secured the right of wardship of burgess orphans.