Chapter XIII: Part 13

Art. 15. Failing proof to the contrary, knowledge of the blockade is
presumed if the vessel left a neutral port subsequently to the
notification of the blockade to the power to which such port belongs,
provided that such notification was made in sufficient time.

Art. 16. If a vessel approaching a blockaded port has no knowledge,
actual or presumptive, of the blockade, the notification must be made
to the vessel itself by an officer of one of the ships of the
blockading force. This notification should be entered in the vessel's
logbook, and must state the day and hour, and the geographical
position of the vessel at the time. If through the negligence of the
officer commanding the blockading force no declaration of blockade has
been notified to the local authorities, or if in the declaration, as
notified, no period has been mentioned within which neutral vessels
may come out, a neutral vessel coming out of the blockaded port must
be allowed to pass free.

Art. 17. Neutral vessels may not be captured for breach of blockade
except within the area of operations of the warships detailed to
render the blockade effective.

Art. 18. The blockading forces must not bar access to neutral ports or
coasts.

Art. 19. Whatever may be the ulterior destination of a vessel or of
her cargo, she cannot be captured for breach of blockade, if, at the
moment, she is on her way to a non-blockaded port.

Art. 20. A vessel which has broken blockade outwards, or which has
attempted to break blockade inwards, is liable to capture so long as
she is pursued by a ship of the blockading force. If the pursuit is
abandoned, or if the blockade is raised, her capture can no longer be
effected.

Art. 21. A vessel found guilty of breach of blockade is liable to
condemnation. The cargo is also condemned, unless it is proved that at
the time of the shipment of the goods the shipper neither knew nor
could have known of the intention to break the blockade. (T. Ba.)

FOOTNOTES:

[1] John Marshall, secretary of state, to Rufus King, minister to
England, 20th of September 1800, Am. State Papers, Class I, For. Rel.
II, No. 181, J.B. Moore, _Digest of International Law_, vii. 788.

[2] James Madison, secretary of state, to Mr Thornton, 27th of
October 1803, 14 MS. Dom. Let. 215. Moore, _Digest of International
Law_, vii. 789.

BLOCKHOUSE, in fortification, a small roofed work serving as a fortified post for a small garrison. The word, common since 1500, is of uncertain origin, and was applied to what is now called a _fort d'arret_, a detached fort blocking the access to a landing, channel, pass, bridge or defile. The modern blockhouse is a building, sometimes of two storeys, which is loopholed on all sides, and not infrequently, in the case of two-storey blockhouses, provided with a _machicoulis_ gallery. Blockhouses are built of wood, brick, stone, corrugated iron or any material available. During the South African War (1899-1902) they were often sent from England to the front in ready-made sections.

BLOEMAERT, ABRAHAM (1564-1651), Dutch painter and engraver, was born at Gorinchem, the son of an architect. He was first a pupil of Gerrit Splinter (pupil of Frans Floris) and of Joos de Beer, at Utrecht. He then spent three years in Paris, studying under several masters, and on his return to his native country received further training from Hieronymus Francken. In 1591 he went to Amsterdam, and four years later settled finally at Utrecht, where he became dean of the Gild of St Luke. He excelled more as a colourist than as a draughtsman, was extremely productive, and painted and etched historical and allegorical pictures, landscapes, still-life, animal pictures and flower pieces. Among his pupils are his four sons, Hendrick, Frederick, Cornelis and Adriaan (all of whom achieved considerable reputation as painters or engravers), the two Honthorsts and Jacob G. Cuyp.

BLOEMEN, JAN FRANS VAN (1662-1740), Flemish painter, was born at Antwerp, and studied and lived in Italy. At Rome he was styled Orizonte, on account of his painting of distance in his landscapes, which are reminiscent of Gaspard Poussin and much admired. His brothers Pieter (1657-1719), styled Standaart (from his military pictures), and Norbert (1670-1746), were also well-known painters.

BLOEMFONTEIN, capital of the Orange Free State, in 29 deg. 8' S., 26 deg. 18' E. It is situated on the open veld, surrounded by a few low kopjes, 4518 ft. above the sea, 105 m. by rail E. by S. of Kimberley, 750 N.E. by E. of Cape Town, 450 N. by E. of Port Elizabeth, and 257 S.W. of Johannesburg.

Bloemfontein is a very pleasant town, regularly laid out with streets running at right angles and a large central market square. Many of the houses are surrounded by large wooded gardens. Through the town runs the Bloemspruit. After a disastrous flood in 1904 the course of this spring was straightened and six stone bridges placed across it. There are several fine public buildings, mostly built of red brick and a fine-grained white stone quarried in the neighbourhood. The Raadzaal, a building in the Renaissance style, faces Market Square. Formerly the meeting-place of the Orange Free State Raad, it is now the seat of the provincial council. In front of the old Raadzaal (used as law courts) is a statue of President Brand. In Douglas Street is an unpretentious building used in turn as a church, a raadzaal, a court-house and a museum. In it was signed (1854) the convention which recognized the independence of the Free State Boers (see ORANGE FREE STATE: _History_). Among the churches the most important, architecturally, are the Dutch Reformed, a building with two spires, and the Anglican cathedral, which has a fine interior. The chief educational establishment is Grey University College, built 1906-1908 at a cost of L125,000. It stands in grounds of 300 acres, a mile and a half from the town. In the town is the original Grey College, founded in 1856 by Sir George Grey, when governor of Cape Colony. The post and telegraph office in Market Square is one of the finest buildings in the town. The public library is housed in a handsome building in Warden Street. Opposite it is the new national museum.

Bloemfontein possesses few manufactures, but is the trading centre of the province. Having a dry healthy climate, it is a favourite residential town and a resort for invalids, being recommended especially for pulmonary disease. The mean maximum temperature is 76.7 deg. Fahr., the mean minimum 45.8 deg.; the mean annual rainfall about 24 in. There is an excellent water-supply, obtained partly from Bloemspruit, but principally from the Modder river at Sanna's Post, 22 m. to the east, and from reservoirs at Moches Dam and Magdepoort.

The population in 1904 was 33,883, of whom, including the garrison of 3487, 15,501 were white, compared with a white population of 2077 in 1890. The coloured inhabitants are mostly Bechuana and Basuto. Most of the whites are of British origin, and English is the common language of all, including the Dutch.

The _spruit_ or spring which gives its name to the town was called after one of the emigrant farmers, Jan Bloem. The town dates from 1846, in which year Major H.D. Warden, then British resident north of the Orange, selected the site as the seat of his administration. When in 1854 independence was conferred on the country the town was chosen by the Boers as the seat of government. It became noted for the intelligence of its citizens, and for the educational advantages it offered at the time when education among the Boers was thought of very lightly. In 1892 the railway connecting it with Cape Town and Johannesburg was completed. During the Anglo-Boer War of 1899-1902 it was occupied by the British under Lord Roberts without resistance (13th of March 1900), fourteen days after the surrender of General Cronje at Paardeberg. In Market Square on the 28th of the following May the annexation of the Orange Free State to the British dominions was proclaimed. In 1907 the first session of the first parliament elected under the constitution granting the colony self-government was held in Bloemfontein. In 1910 when the colony became a province of the Union of South Africa under its old designation of Orange Free State, Bloemfontein was chosen as the seat of the Supreme Court of South Africa. Its growth as a business centre after the close of the war in 1902 was very marked. The rateable value increased from L709,000 in 1901 to L2,400,000 in 1905.

BLOET, ROBERT (d. 1123), English bishop, was chancellor to William I. and Rufus. From the latter he received the see of Lincoln (1093) in succession to Remigius. His private character was indifferent; but he administered his see with skill and prudence, built largely, and kept a magnificent household, which served as a training-school even for the sons of nobles. Bloet was active in assisting Henry I. during the rebellion of 1102, and became that monarch's justiciar. Latterly, however, he fell out of favour, and, although he had been very rich, was impoverished by the fines which the king extorted from him. Perhaps his wealth was his chief offence in the king's eyes; for he was in attendance on Henry when seized with his last illness. He was the patron of the chronicler Henry of Huntingdon, whom he advanced to an archdeaconry.

Henry of Huntingdon and W. Malmesbury (_De Gestis Pontificum_) are
original authorities. See E.A. Freeman's _William Rufus_; Sir James
Ramsay, _The Foundations of England_, vol. ii. (H. W. C. D.)

BLOIS, LOUIS DE (1506-1566), Flemish mystical writer, generally known under the name of BLOSIUS, was born in October 1506 at the chateau of Donstienne, near Liege, of an illustrious family to which several crowned heads were allied. He was educated at the court of the Netherlands with the future emperor Charles V. of Germany, who remained to the last his staunch friend. At the age of fourteen he received the Benedictine habit in the monastery of Liessics in Hainaut, of which he became abbot in 1530. Charles V. pressed in vain upon him the archbishopric of Cambrai, but Blosius studiously exerted himself in the reform of his monastery and in the composition of devotional works. He died at his monastery on the 7th of January 1566.

Blosius's works, which were written in Latin, have been translated into almost every European language, and have appealed not only to Roman Catholics, but to many English laymen of note, such as W.E. Gladstone and Lord Coleridge. The best editions of his collected works are the first edition by J. Frojus (Louvain, 1568), and the Cologne reprints (1572, 1587). His best-known works are:--the _Institutio Spiritualis_ (Eng. trans., _A Book of Spiritual Instruction_, London, 1900); _Consolatio Pusillanimium_ (Eng. trans., _Comfort for the Faint-Hearted_, London, 1903); _Sacellum Animae Fidelis_ (Eng. trans., _The Sanctuary of the Faithful Soul_, London, 1905); all these three works were translated and edited by Father Bertrand Wilberforce, O.P., and have been reprinted several times; and especially _Speculum Monachorum_ (French trans. by Felicite de Lamennais, Paris, 1809; Eng. trans., Paris, 1676; re-edited by Lord Coleridge, London, 1871, 1872, and inserted in "Paternoster" series, 1901).

See Georges de Blois, _Louis de Blois, un Benedictin au XVI^eme
siecle_ (Paris, 1875), Eng. trans. by Lady Lovat (London, 1878, &c.).

BLOIS, a town of central France, capital of the department of Loir-et-Cher, 35 m. S.W. of Orleans, on the Orleans railway between that city and Tours. Pop. (1906) 18,457. Situated in a thickly-wooded district on the right bank of the Loire, it covers the summits and slopes of two eminences between which runs the principal thoroughfare of the town named after the philosopher Denis Papin. A bridge of the 18th century from which it presents the appearance of an amphitheatre, unites Blois with the suburb of Vienne on the left bank of the river. The streets of the higher and older part of the town are narrow and tortuous, and in places so steep that means of ascent is provided by flights of steps. The famous chateau of the family of Orleans (see ARCHITECTURE: _Renaissance Architecture in France_), a fine example of Renaissance architecture, stands on the more westerly of the two hills. It consists of three main wings, and a fourth and smaller wing, and is built round a courtyard. The most interesting portion is the north-west wing, which was erected by Francis I., and contains the room where Henry, duke of Guise, was assassinated by order of Henry III. The striking feature of the interior facade is the celebrated spiral staircase tower, the bays of which, with their beautifully sculptured balustrades, project into the courtyard (see ARCHITECTURE, Plate VIII. fig. 84). The north-east wing, in which is the entrance to the castle, was built by Louis XII. and is called after him; it contains picture-galleries and a museum. Opposite is the Gaston wing, erected by Gaston, duke of Orleans, brother of Louis XIII., which contains a majestic domed staircase. In the north corner of the courtyard is the Salle des Etats, which, together with the donjon in the west corner, survives from the 13th century. Of the churches of Blois, the cathedral of St Louis, a building of the end of the 17th century, but in Gothic style, is surpassed in interest by St Nicolas, once the church of the abbey of St Laumer, and dating from the 12th and 13th centuries. The picturesqueness of the town is enhanced by many old mansions, the chief of which is the Renaissance Hotel d'Alluye, and by numerous fountains, among which that named after Louis XII. is of very graceful design. The prefecture, the law court, the corn-market and the fine stud-buildings are among the chief modern buildings.

Blois is the seat of a bishop, a prefect, and a court of assizes. It has a tribunal of first instance, a tribunal of commerce, a board of trade arbitration, a branch of the Bank of France, a communal college and training-colleges. The town is a market for the agricultural and pastoral regions of Beauce and Sologne, and has a considerable trade in grain, the wines of the Loire valley, and in horses and other live-stock. It manufactures boots and shoes, biscuits, chocolate, upholstering materials, furniture, machinery and earthenware, and has vinegar-works, breweries, leather-works and foundries.

Though of ancient origin, Blois is first distinctly mentioned by Gregory of Tours in the 6th century, and was not of any importance till the 9th century, when it became the seat of a powerful countship (see below). In 1196 Count Louis granted privileges to the townsmen; the commune, which survived throughout the middle ages, probably dated from this time. The counts of the Chatillon line resided at Blois more often than their predecessors, and the oldest parts of the chateau (13th century) were built by them. In 1429 Joan of Arc made Blois her base of operations for the relief of Orleans. After his captivity in England, Charles of Orleans in 1440 took up his residence in the chateau, where in 1462 his son, afterwards Louis XII., was born. In the 16th century Blois was often the resort of the French court. Its inhabitants included many Calvinists, and it was in 1562 and 1567 the scene of struggles between them and the supporters of the Roman church. In 1576 and 1588 Henry III., king of France, chose Blois as the meeting-place of the states-general, and in the latter year he brought about the murders of Henry, duke of Guise, and his brother, Louis, archbishop of Reims and cardinal, in the chateau, where their deaths were shortly followed by that of the queen-mother, Catherine de' Medici. From 1617 to 1619 Marie de' Medici, wife of King Henry IV., exiled from the court, lived at the chateau, which was soon afterwards given by Louis XIII. to his brother Gaston, duke of Orleans, who lived there till his death in 1660. The bishopric dates from the end of the 17th century. In 1814 Blois was for a short time the seat of the regency of Marie Louise, wife of Napoleon I.

See L. de la Saussaye, _Blois et ses environs_ (1873); _Histoire du
chateau de Blois_ (1873); L. Bergevin et A. Dupre, _Histoire de Blois_
(1847).

BLOIS, COUNTSHIP OF. From 865 to about 940 the countship of Blois was one of those which were held in fee by the margrave of Neustria, Robert the Strong, and by his successors, the abbot Hugh, Odo (or Eudes), Robert II. and Hugh the Great. It then passed, about 940 and for nearly three centuries, to a new family of counts, whose chiefs, at first vassals of the dukes of France, Hugh the Great and Hugh Capet, became in 987, by the accession of the Capetian dynasty to the throne of France, the direct vassals of the crown. These new counts were orjginally very powerful. With the countship of Blois they united, from 940 to 1044, that of Touraine, and from about 950 to 1218, and afterwards from 1269 to 1286, the countship of Chartres remained in their possession.

The counts of Blois of the house of the Theobalds (Thibauds) began with Theobald I., the Cheat, who became count about 940. He was succeeded by his son, Odo (Eudes) I., about 975. Theobald II., eldest son of Odo I., became count in 996, and was succeeded by Odo II., younger son of Odo I., about 1005. Odo II. was one of the most warlike barons of his time. With the already considerable domains which he held from his ancestors, he united the heritage of his kinsman, Stephen I., count of Troyes. In 1033 he disputed the crown of Burgundy with the emperor, Conrad the Salic, and perished in 1037 while fighting in Lorraine. He was succeeded in 1037 by his eldest son, Theobald III., who was defeated by the Angevins in 1044, and was forced to give up the town of Tours and its dependencies to the count of Anjou. In 1089 Stephen Henry, eldest son of Theobald III., became count. He took part in the first crusade, fell into the hands of the Saracens, and died in captivity; he married Adela, daughter of William I., king of England. In 1102 Stephen Henry was succeeded by his son, Theobald IV. the Great, who united the countship of Troyes with his domains in 1128. In 1135, on the death of his maternal uncle, Henry I., king of England, he was called to Normandy by the barons of the duchy, but soon renounced his claims on learning that his younger brother, Stephen, had just been proclaimed king of England. In 1152 Theobald V. the Good, second son of Theobald IV., became count; he died in 1191 in Syria, at the siege of Acre. His son Louis succeeded in 1191, took part in the fourth crusade, and after the taking of Constantinople was rewarded with the duchy of Nicaea. He was killed at the battle of Adrianople in 1205, in which year he was succeeded by his son, Theobald VI. the Young, who died childless. In 1218 the countship passed to Margaret, eldest daughter of Theobald V., and to Walter (Gautier) of Avesnes, her third husband.

The Chatillon branch of the counts of Blois began in 1230 with Mary of Avesnes, daughter of Margaret of Blois and her husband, Hugh of Chatillon, count of St Pol. In 1241 her brother, John of Chatillon, became count of Blois, and was succeeded in 1279 by his daughter, Joan of Chatillon, who married Peter, count of Alencon, fifth son of Louis IX., king of France. In 1286 Joan sold the countship of Chartres to the king of France. Hugh of Chatillon, her first-cousin, became count of Blois in 1293, and was succeeded by his son, Guy I., in 1307. In 1342 Louis II., eldest son of Guy I., died at the battle of Crecy, and his brother, Charles of Blois, disputed the duchy of Brittany with John of Montfort. Louis III., eldest son of Louis II., became count in 1346, and was succeeded by John II., second son of Louis II., in 1372. In 1381 Guy II., brother of Louis III. and John II., succeeded in 1381, but died childless. Overwhelmed with debt, he had sold the countship of Blois to Louis I., duke of Orleans, brother of King Charles VI., who took possession of it in 1397.

In 1498 the countship of Blois was united with the crown by the accession of King Louis XII., grandson and second successor of Louis I., duke of Orleans.

See Bernier, _Histoire de Blois_ (1682); La Saussaye, _Histoire de la
ville de Blois_ (1846). (A. Lo.)

BLOMEFIELD, FRANCIS (1705-1752), English topographer of the county of Norfolk, was born at Fersfield, Norfolk, on the 23rd of July 1705. On leaving Cambridge in 1727 he was ordained, becoming in 1729 rector of Hargham, Norfolk, and immediately afterwards rector of Fersfield, his father's family living. In 1733 he mooted the idea of a history of Norfolk, for which he had begun collecting material at the age of fifteen, and shortly afterwards, while collecting further information for his book, discovered some of the famous _Paston Letters_. By 1736 he was ready to put some of the results of his researches into type. At the end of 1739 the first volume of the _History of Norfolk_ was completed. It was printed at the author's own press, bought specially for the purpose. The second volume was ready in 1745. There is little doubt that in compiling his book Blomefield had frequent recourse to the existing historical collections of Le Neve, Kirkpatrick and Tanner, his own work being to a large extent one of expansion and addition. To Le Neve in particular a large share of the credit is due. When half-way through his third volume, Blomefield, who had come up to London in connexion with a special piece of research, caught smallpox, of which he died on the 16th of January 1752. The remainder of his work was published posthumously, and the whole eleven volumes were republished in London between 1805 and 1810.

BLOMFIELD, SIR ARTHUR WILLIAM (1829-1899), English architect, son of Bishop C.J. Blomfield, was born on the 6th of March 1829, and educated at Rugby and Trinity, Cambridge. He was then articled as an architect to P.C. Hardwick, and subsequently obtained a large practice on his own account. He became president of the Architectural Association in 1861, and a fellow (1867) and vice-president (1886) of the Royal Institute of British Architects. In 1887 he became architect to the Bank of England, and designed the law courts branch in Fleet Street, and he was associated with A.E. Street in the building of the law courts. In 1889 he was knighted. He died on the 30th of October 1899. He was twice married, and brought up two sons, Charles J. Blomfield and Arthur Conran Blomfield, to his own profession, of which they became distinguished representatives. Among the numerous churches which Sir Arthur Blomfield designed, his work at St Saviour's, Southwark, is a notable example of his use of revived Gothic, and he was highly regarded as a restorer.

BLOMFIELD, CHARLES JAMES (1786-1857), English divine, was born on the 29th of May 1786 at Bury St Edmunds. He was educated at the local grammar school and at Trinity College, Cambridge, where he gained the Browne medals for Latin and Greek odes, and carried off the Craven scholarship. In 1808 he graduated as third wrangler and first medallist, and in the following year was elected to a fellowship at Trinity College. The first-fruits of his scholarship was an edition of the _Prometheus_ of Aeschylus in 1810; this was followed by editions of the _Septem contra Thebas, Persae, Choephorae_, and _Agamemnon_, of Callimachus, and of the fragments of Sappho, Sophron and Alcaeus. Blomfield, however, soon ceased to devote himself entirely to scholarship. He had been ordained in 1810, and held in quick succession the livings of Chesterford, Quarrington, Dunton, Great and Little Chesterford, and Tuddenham. In 1817 he was appointed private chaplain to Wm. Howley, bishop of London. In 1819 he was nominated to the rich living of St Botolph's, Bishopsgate, and in 1822 he became archdeacon of Colchester. Two years later he was raised to the bishopric of Chester where he carried through many much-needed reforms. In 1828 he was translated to the bishopric of London, which he held for twenty-eight years. During this period his energy and zeal did much to extend the influence of the church. He was one of the best debaters in the House of Lords, took a leading position in the action for church reform which culminated in the ecclesiastical commission, and did much for the extension of the colonial episcopate; and his genial and kindly nature made him an invaluable mediator in the controversies arising out of the tractarian movement. His health at last gave way, and in 1856 he was permitted to resign his bishopric, retaining Fulham Palace as his residence, with a pension of L6000 per annum. He died on the 5th of August 1857. His published works, exclusive of those above mentioned, consist of charges, sermons, lectures and pamphlets, and of a _Manual of Private and Family Prayers_. He was a frequent contributor to the quarterly reviews, chiefly on classical subjects.

See _Memoirs of Charles James Blomfield, D.D., Bishop of London, with
Selections from his Correspondence_, edited by his son, Alfred
Blomfield (1863); G.E. Biber, _Bishop Blomfield and his Times_ (1857).

BLOMFIELD, EDWARD VALENTINE (1788-1816), English classical scholar, brother of Bishop C.J. Blomfield, was born at Bury St Edmunds on the 14th of February 1788. Going to Caius College, Cambridge, he was thirteenth wrangler in 1811, obtained several of the classical prizes of the university, and became a fellow and lecturer at Emmanuel College. In 1813 he travelled in Germany and made the acquaintance of some of the great scholars of Germany. On his return, he published in the _Museum Criticum_ (No. ii.) an interesting paper on "The Present State of Classical Literature in Germany." Blomfield is chiefly known by his translation of Matthiae's _Greek Grammar_ (1819), which was prepared for the press by his brother. He died on the 9th of October 1816, his early death depriving Cambridge of one who seemed destined to take a high place amongst her most brilliant classical scholars.

See "Memoir of Edward Valentine Blomfield," by Bishop Monk, in _Museum
Criticum_, No. vii.

BLONDEL, DAVID (1591-1655), French Protestant clergyman, was born at Chalons-sur-Marne in 1591, and died on the 6th of April 1655. In 1650 he succeeded G.J. Vossius in the professorship of history at Amsterdam. His works were very numerous; in some of them he showed a remarkable critical faculty, as in his dissertation on Pope Joan (1647, 1657), in which he came to the conclusion, now universally accepted, that the whole story is a mere myth. Considerable Protestant indignation was excited against him on account of this book.

BLONDEL, JACQUES FRANCOIS (1705-1774), French architect, began life as an architectural engraver, but developed into an architect of considerable distinction, if of no great originality. As architect to Louis XV. from 1755 he necessarily did much in the rococo manner, although it would seem that he conformed to fashion rather than to artistic conviction. He was among the earliest founders of schools of architecture in France, and for this he was distinguished by the Academy; but he is now best remembered by his voluminous work _L'Architecture francaise_, in which he was the continuator of Marot. The book is a precious collection of views of famous buildings, many of which have disappeared or been remodelled.

BLONDIN (1824-1897), French tight-rope walker and acrobat, was born at St Omer, France, on the 28th of February 1824. His real name was Jean Francois Gravelet. When five years old he was sent to the Ecole de Gymnase at Lyons and, after six months' training as an acrobat, made his first public appearance as "The Little Wonder." His superior skill and grace as well as the originality of the settings of his acts, made him a popular favourite. He especially owed his celebrity and fortune to his idea of crossing Niagara Falls on a tight-rope, 1100 ft. long, 160 ft. above the water. This he accomplished, first in 1859, a number of times, always with different theatric variations: blindfold, in a sack, trundling a wheelbarrow, on stilts, carrying a man on his back, sitting down midway while he made and ate an omelette. In 1861 Blondin first appeared in London, at the Crystal Palace, turning somersaults on stilts on a rope stretched across the central transept, 170 ft. from the ground. In 1862 he again gave a series of performances at the Crystal Palace, and elsewhere in England, and on the continent. After a period of retirement he reappeared in 1880, his final performance being given at Belfast in 1896. He died at Ealing, London, on the 19th of February 1897.

BLOOD, the circulating fluid in the veins and arteries of animals. The word itself is common to Teutonic languages; the O. Eng. is _blod_, cf. Gothic _bloth_, Dutch _bloed_, Ger. _Blut_. It is probably ultimately connected with the root which appears in "blow," "bloom," meaning flourishing or vigorous. The Gr. word for blood, [Greek: aima], appears as a prefix _haemo-_ in many compound words. As that on which the life depends, as the supposed seat of the passions and emotions, and as that part which a child is believed chiefly to inherit from its parents, the word "blood" is used in many figurative and transferred senses; thus "to have his blood," "to fire the blood," "cold blood," "blood-royal," "half" or "whole blood," &c. The expression "blue blood" is from the Spanish _sangre azul._ The nobles of Castile claimed to be free from all admixture with the darker blood of Moors or Jews, a proof being supposed to lie in the blue veins that showed in their fairer skins. The common English expletive "bloody," used as an adjective or adverb, has been given many fanciful origins; it has been supposed to be a contraction of "by our Lady," or an adaptation of the oath common during the 17th century, "'sblood," a contraction of "God's blood." The exact origin of the expression is not quite clear, but it is certainly merely an application of the adjective formed from "blood." The _New English Dictionary_ suggests that it refers to the use of "blood" for a young rowdy of aristocratic birth, which was common at the end of the 17th century, and later became synonymous with "dandy," "buck," &c.; "bloody drunk" meant therefore "drunk as a blood," "drunk as a lord." The expression came into common colloquial use as a mere intensive, and was so used till the middle of the 18th century. There can be little doubt that the use of the word has been considerably affected by the idea of blood as the vital principle, and therefore something strong, vigorous, and parallel as an intensive epithet with such expressions as "thundering," "awfully" and the like.

ANATOMY AND PHYSIOLOGY

In all living organisms, except the most minute, only a minimum number of cells can come into immediate contact with the general world, whence is to be drawn the food supply for the whole organism. Hence those cells--and they are by far the most numerous--which do not lie on the food-absorbing surface, must gain their nutriment by some indirect means. Further, each living cell produces waste products whose accumulation would speedily prove injurious to the cell, hence they must be constantly removed from its immediate neighbourhood and indeed from the organism as a whole. In this instance again, only a few cells can lie on a surface whence such materials can be directly discharged to the exterior. Hence the main number of the cells of the organism must depend upon some mechanism by which the waste products can be carried away from them to that group of cells whose duty it is to modify them, or discharge them from the body. These two ends are attained by the aid of a circulating fluid, a fluid which is constantly flowing past every cell of the body. From it the cells extract the food materials they require for their sustenance, and into it they discharge the waste materials resulting from their activity. This circulating medium is the blood.

Whilst undoubtedly the two functions of this circulating fluid above given are the more prominent, there are yet others of great importance. For instance, it is known that many tissues as a result of their activity produce certain chemical substances which are of essential importance to the life of other tissue cells. These substances--_internal secretions_ as they are termed--are carried to the second tissue by the blood stream. Again, many instances are known in which two distant tissues communicate with one another by means of chemical messengers, bodies termed _hormones_ ([Greek: ormaein], to stir up), which are produced by one group of cells, and sent to the other group to excite them to activity. Here, also, the path by which such messengers travel is the blood stream. A further and most important manner in which the circulating fluid is utilized in the life of an animal is seen in the way in which it is employed in protecting the body should it be invaded by micro-organisms.

Hence it is clear that the blood is of the most vital importance to the healthy life of the body. But the fact that it is present as a circulating medium exposes the animal to a great danger, viz. that it may be lost should any vessel carrying it become ruptured. This is constantly liable to happen, but to minimize as far as possible any such loss, the blood is endowed with the peculiar property of _clotting_, i.e. of setting to a solid or stiff jelly by means of which the orifices of the torn vessels become plugged and the bleeding stayed.

The performance of these essential functions depends upon the maintenance of a continuous flow past all tissue cells, and this is attained by the circulatory mechanism, consisting of a central pump, the heart, and a system of ramifying tubes, the arteries, through which the blood is forced from the heart to every tissue (see VASCULAR SYSTEM). A second set of tubes, the veins, collects the blood and returns it to the heart. In many invertebrates the circulating fluid is actually poured into the tissue spaces from the open terminals of the arteries. From these spaces it is in turn drained away by the veins. Such a system is termed a _haemolymph system_ and the circulating fluid the haemolymph. Here the essential point gained is that the fluid is brought into direct contact with the tissue cells. In all vertebrates, the ends of the arteries are united to the commencements of the veins by a plexus of extremely minute tubes, the capillaries, consequently the blood is always retained within closed tubes and never comes into contact with the tissue cells. It is while passing through the capillaries that the blood performs its work; here the blood stream is at its slowest and is brought nearest to the tissue cell, only being separated from it by the extremely thin wall of the capillary and by an equally thin layer of fluid. Through this narrow barrier the interchanges between cell and blood take place.

The advantage gained in the vertebrate animal by retaining the blood in a closed system of tubes lies in the great diminution of resistance to the flow of blood, and the consequent great increase in rate of flow past the tissue cells. Hence any food stuffs which can travel quickly through the capillary wall to the tissue cell outside can be supplied in proportionately greater quantity within a given time, without requiring any very great increase in the concentration of that substance in the blood. Conversely, any highly diffusible substance may be withdrawn from the tissues by the blood at a similarly increased pace. These conditions are more peculiarly of importance for the supply of oxygen and the removal of carbonic acid-especially for the former, because the amount of it which can be carried by the blood is small. But as the rate at which a tissue lives, _i.e_. its activity, depends upon the rate of its chemical reactions, and as these are fundamentally oxidative, the more rapidly oxygen is carried to a tissue the more rapidly it can live, and the greater the amount of work it can perform within a given time. The rate of supply is of much less importance in the case of the other food substances because they are far more soluble in water, so that the supply in sufficient quantity can easily be met by a relatively slow blood flow. Hence we find that the gradual evolution of the animal kingdom goes hand in hand with the gradual development of a greater oxygen-carrying capacity of the blood and an increase in the rate of its flow.

In the groundwork of a tissue are a number of spaces--the _tissue spaces_. They are filled with fluid and intercommunicate freely, finally connecting with a number of fine tubes, the lymphatics, through which excess of fluid or any solid particles present are drained away. The contained fluid acts as an intermediary between the blood and the cell; from it, the cell takes its various food stuffs, these having in the first instance been derived from the blood, and into it the cell discharges its waste products. On the course of the lymphatics a number of typical structures, the lymphatic glands, are placed, and the lymph has to pass through these structures where any deleterious products are retained, and the fluid thus purified is drained away by further lymphatics and finally returned to the blood. Thus there is a second stream of fluid from the tissues, but one vastly slower than that of the blood. The flow is too slow for it to act as the vehicle for the removal of those waste products (carbonic acid, &c.) which must of necessity be removed quickly. These must be removed by the blood. The same is true for the main number of other waste products, which, however, being of small molecular size are readily absorbed into the blood stream.

But in addition to fluid, the tissue spaces may at times be found to contain solid matter in the form of particles, which may represent the debris of destroyed cells, or which are, as is quite commonly the case, micro-organisms. Apparently such material cannot be removed from a tissue by absorption into the blood stream--indeed in the case of living organisms such an absorption would in many instances rapidly prove fatal, and special provision is made to prevent such an accident. These, therefore, are made to travel along the lymphatic channels, and so, before gaining access to the blood stream and thus to the body generally, have to run the gauntlet of the protective mechanism provided by the lymphatic glands, where in the major number of cases they are readily destroyed.

Hence we see that first and foremost we have to regard the blood as a food-carrier to all the cells of the body; in the second place as the vehicle carrying away most if not all the waste products; in a third direction, it is acting as a means for transmitting chemical substances manufactured in one tissue to distant cells of the body for whose nutrition or excitation they may be essential; and in addition to these important functions there is yet another whose value it is almost impossible to overestimate, for it plays the essential role in rendering the animal immune to the attacks of invading organisms. The question of immunity is discussed elsewhere, and it is sufficient merely to indicate the chief means by which the blood subserves this essential protective mechanism. Should living organisms find their way into the surface cells or within the tissue spaces, the body fights them in a number of ways, (1) It may produce one or more chemical substances capable of neutralizing the toxic material produced by the organism. (2) It may produce chemical substances which act as poisons to the micro-organism, either paralysing it or actually killing it. Or (3) the organism may be attacked and taken up into the body of wandering cells, _e.g_. certain of the leucocytes, and then digested by them. Such cells are therefore called phagocytes ([Greek: Phagein], to eat). Thus, by its power of reacting in these ways the body has become capable of withstanding the attacks of many different varieties of micro-organisms, of both animal and vegetable origin.

_General Properties._--Blood is an opaque, viscid liquid of bright red colour possessing a distinct and characteristic odour, especially when warm. Its opacity is due to the presence of a very large number of solid particles, the blood corpuscles, having a higher refractive index than that of the liquid in which they float. The specific gravity in man averages about 1.055. The specific gravity of the liquid portion, the plasma (Gr. [Greek: plasma], something formed or moulded, [Greek: plassein], to mould), is about 1.027, whilst that of the corpuscles amounts to 1.088. To litmus it reacts as a weak alkali.

_Blood Plasma._--The plasma is a solution in water of a varied number of substances, and as a solvent it confers on the blood its power of acting as a carrier of food stuffs and waste products. One important food substance, oxygen, is, however, only partly carried in solution, being mainly combined with haemoglobin in the red corpuscles. The food stuffs carried by the plasma are proteins, carbohydrates, salts and water. The main waste products dissolved in it are ammonium carbonate, urea, urates, xanthin bases, creatin and small amounts of other nitrogenous bodies, carbonic acid as carbonates, other carbon compounds such as cholesterin, lecithin and a number of other substances. Thus, if we take mammalian blood as a type, the plasma would have the following approximate composition:--

In 1000 grms. plasma--
Water 901.51
Substances not vaporizing at 120 deg. C.--
Fibrin 8.06
Other proteins and organic substances 81.92
Inorganic substances--
Chlorine 3.536
Sulphuric acid 0.129
Phosphoric acid 0.145
Potassium 0.314
Sodium 3.410
Calcium 0.298
Magnesium 0.218
Oxygen 0.455
----- 8.505
----- 98.49
-------
1000.00

_Proteins._--The proteins of the blood plasma belong to the two classes of the albumins and the globulins. The globulins present are named fibrinogen and serum-globulin; as its name implies, the chief physiological property of fibrinogen is that it can give rise to fibrin, the solid substance formed when blood clots. It possesses the typical properties of a globulin, i.e. it coagulates on heating (in this instance at a temperature of 56 deg.C.), and is precipitated by half saturating its solution with ammonium sulphate. It differs from other globulins in that it is less soluble. It is only present in very small quantities, 0.4%. The other globulin, serum-globulin, is not coagulated until 75 deg.C. is reached, and we now know that it is in reality a mixture of several proteins, but so far these have not been completely separated from one another and obtained in a pure form. On dialysing a solution of serum-globulin a part is precipitated, and this portion has been termed the eu-globulin fraction, the remainder being known, in contradistinction, as the pseudo-globulin. Again, on diluting a solution and adding a small amount of acetic acid a precipitate is formed which in some respects differs from the remainder of the globulin present. Whether in these two instances we are dealing with approximately pure substances is extremely doubtful. A further important point in connexion with the chemistry of the globulins is that dextrose may be found among their decomposition products, i.e. that a part of it, or possibly the whole, possesses a glucoside character.

Serum-albumin gives all the typical colour and precipitation reactions of the albumins. If plasma be weakly acidified with sulphuric acid, then treated with crystals of ammonium sulphate until a slight precipitate forms, filtered and the filtrate allowed to evaporate very slowly, typical crystals of serum-albumin may form. According to many it is a uniform and specific substance, but others hold the view that it consists of at least three distinct substances, as shown by the fact that if a solution be gradually heated coagulation will occur at three different temperatures, viz. at 73 deg., 77 deg. and 84 deg. C. On the other hand the close agreement between different analyses of even the amorphous preparations points to there being but one serum-albumin.

When blood clots two new proteins make their appearance in the fluid part of the blood, or serum, as it is now called. The first of these is fibrin ferment (for its origin see section on _Clotting_ below). The other, fibrinoglobulin, possesses all the typical characteristics of the globulins and coagulates at 64 deg. C.

_Carbohydrates._--Three several carbohydrates are described as occurring in plasma, viz. glycogen, animal gum and dextrose. If glycogen is present in solution in the plasma it is there in very small quantities only, and has probably arisen from the destruction of the white blood corpuscles, since some leucocytes undoubtedly contain glycogen. A small amount of carbohydrate having the formula for starch and yielding a reducing sugar on hydrolysis with acid has also been described. The constant carbohydrate constituent of plasma, however, is dextrose. This is present to the approximate amount of 0.15% in arterial blood. The amount may be much greater in the blood of the portal vein during carbohydrate absorption, and according to some observers there is less in venous than in arterial blood, but the difference is small and falls within the error of observation. The statement that when no absorption is taking place the blood of the hepatic vein is richer in dextrose than that of the portal vein (Bernard) is denied by Pavy.

_Fats._--Plasma or serum is as a rule quite clear, but after a meal rich in fats it may become quite milky owing to the presence of neutral fats in a very fine state of subdivision. This suspended fat rapidly disappears from the blood after fat absorption has ceased. To some extent it varies in composition with that of the fat absorbed, but usually consists of the glycerides of the common fatty acids--palmitic, stearic and oleic. In addition, there is a small amount of fatty acid in solution in the plasma. As to the form in which this occurs there is some uncertainty. It is possibly present as a soap or even as a neutral fat, since a little can be dissolved in plasma, the solvent substance being probably protein or cholesterin. Fatty acids also appear to be present to some extent combined with cholesterin forming cholesterin esters (about 0.06%).

_Other Organic Compounds._--In addition to the substances above described, belonging to the three main classes of food stuffs, there are still other organic bodies present in plasma in small amounts, which for convenience we may classify as non-nitrogenous and nitrogenous. Among the former may be mentioned lactic acid, glycerin, a lipochrome, and probably many other substances of a similar type whose separation has not yet been effected.

The non-protein nitrogenous constituents consist of the following: ammonia as carbonate or carbamate (0.2 to 0.6%), urea (0.02 to 0.05%), creatine, creatinine, uric acid, xanthine, hypoxanthine and occasionally hippuric acid. Three ferments are also described as being present: (1) a glycolytic ferment exerting an action upon dextrose; (2) a lipase or fat-splitting ferment; and (3) a diastase capable of converting starch into sugar.

_Salts._--The saline constituents of plasma comprise chlorides, phosphates, carbonates and possibly sulphates, of sodium, potassium, calcium and magnesium. The most abundant metal is sodium and the most abundant acid is hydrochloric. These two are present in sufficient amount to form about 0.65% of sodium chloride. The phosphate is present to about 0.02%. Sulphuric acid is always present if the blood has been calcined for the purposes of the analysis, and may then be present to about 0.013%. This is, however, probably produced during the destruction of the protein, since it has been shown that no sulphate can be removed from normal plasma by dialysis. The amount of potassium present (0.03%) is less than one-tenth of that of the sodium, and the quantities of calcium and magnesium are even less.

_Formed Elements._--When viewed under the microscope the main number of these are seen to be small yellow bodies of very uniform size, size and shape varying, however, in different animals. When observed in bulk they have a red colour, their presence in fact giving the typical colour to blood. These are the _red blood corpuscles_ or _erythrocytes_ (Gr. [Greek: erythros], red). Mingled with them in the blood are a smaller number of corpuscles which possess no colour and have therefore been called _white blood corpuscles_ or _leucocytes_ (Gr. [Greek: leukos], white). Lastly, there are present a large number of small lens-shaped structures, less in number than the red corpuscles, and much more difficult to distinguish. These are known as _blood platelets_.

_Red Corpuscles._--These are present in very large numbers and, under normal conditions, all possess exactly the same appearance. With rare exceptions their shape is that of a biconcave disk with bevelled edges, the size varying somewhat in different animals, as is seen in the following table which gives their diameters:--

Man 0.0075 mm.
Dog 0.0073 mm.
Rabbit 0.0069 mm.
Cat 0.0065 mm.
Goat 0.0041 mm.

The coloured corpuscles of amphibia as well as of nearly all vertebrates below mammals are biconvex and elliptical. The following are the dimensions of some of the more common:--

Pigeon 0.0147 mm. long by 0.0065 mm. wide.
Frog 0.0223 " " 0.0157 " "
Newt 0.0293 " " 0.0195 " "
Proteus 0.0580 " " 0.0350 " "
Amphiuma 0.0770 " " 0.0460 " "

Their number also varies as follows:--

Man 4,000,000 to 5,000,000 per cub. mm.
Goat 9,000,000 to 10,000,000 " "
Sheep 13,000,000 to 14,000,000 " "
Birds 1,000,000 to 4,000,000 " "
Fish 250,000 to 2,000,000 " "
Frog 500,000 per cub. mm.
Proteus 36,000 " "

In mammals they are apparently homogeneous in structure, have no nucleus, but possess a thin envelope. Their specific gravity is distinctly higher than that of the plasma (1.088), so that if clotting has been prevented, blood on standing yields a large deposit which may form as much as half the total volume of the blood.

_Chemical Composition._--On destruction the red corpuscles yield two chief proteins, haemoglobin and a nucleo-protein, and a number of other substances similar to those usually obtained on the break-down of any cellular tissue, such for instance as lecithin, cholesterin and inorganic salts. The most important protein is the haemoglobin. To it the corpuscle owes its distinctive property of acting as an oxygen carrier, for it possesses the power of combining chemically with oxygen and of yielding up that same oxygen whenever there is a decrease in the concentration of the oxygen in the solvent. Thus in a given solution of haemoglobin the amount of it which is combined with oxygen depends absolutely on the oxygen concentration. The greatest dissociation of oxyhaemoglobin occurs as the oxygen tension falls from about 40 to 20 mm. of mercury. That the oxygen forms a definite compound with the haemoglobin is proved by the fact that haemoglobin thoroughly saturated with oxygen (oxyhaemoglobin) has a definite absorption spectrum showing two bands between the D and E lines, whilst haemoglobin from which the oxygen has been completely removed only gives one band between those lines. In association with this, oxyhaemoglobin has a typical bright red colour, whereas haemoglobin is dark purple. A further striking characteristic of haemoglobin is that it contains iron in its molecule. The amount present, though small bears a perfectly definite quantitative relation to the amount of oxygen with which the haemoglobin is capable of combining (two atoms of oxygen to one of iron). One gram of haemoglobin crystals can combine with 1.34 cc. of oxygen. On destruction with an acid or alkali, haemoglobin yields a pigment portion, haematin, and a protein portion, globin, the latter belonging to the group of the histones (Gr. [Greek: istos], web, tissue). In this cleavage the iron is found in the pigment. By the use of a strong acid, it may be made to yield iron-free pigment, the remainder of the molecule being much further decomposed.