Authorities.—Henry Charles Lea,History of Sacerdotal Celibacy(3rd ed., 1907, 2 vols), is by far the fullest and best work on this subject, though a good deal of important matter omitted by Dr Lea may be found inDie Einfuhrung der erzwungenen Ehelosigkeitby the brothers Johann Anton and Augustin Theiner, which was put on the RomanIndex, though Augustin afterwards became archivist at the Vatican (Altenburg, 1828, 2 vols.). The history of monastic celibacy has not yet been fully treated anywhere; the most important evidence of the episcopal registers is either still in MS. or has been published only in comparatively recent years. The most learned work on clerical celibacy from the strictly conservative point of view is that of Francesco Antonio Zaccaria,Storia Polemica del celibato sacro(Rome, 1774); but many of his most importantconclusions are set aside by the abbé E. Vacandard in his contribution to theDictionnaire de théologie catholique(vol. ii. art. “Célibat ecclésiastique”).
Authorities.—Henry Charles Lea,History of Sacerdotal Celibacy(3rd ed., 1907, 2 vols), is by far the fullest and best work on this subject, though a good deal of important matter omitted by Dr Lea may be found inDie Einfuhrung der erzwungenen Ehelosigkeitby the brothers Johann Anton and Augustin Theiner, which was put on the RomanIndex, though Augustin afterwards became archivist at the Vatican (Altenburg, 1828, 2 vols.). The history of monastic celibacy has not yet been fully treated anywhere; the most important evidence of the episcopal registers is either still in MS. or has been published only in comparatively recent years. The most learned work on clerical celibacy from the strictly conservative point of view is that of Francesco Antonio Zaccaria,Storia Polemica del celibato sacro(Rome, 1774); but many of his most importantconclusions are set aside by the abbé E. Vacandard in his contribution to theDictionnaire de théologie catholique(vol. ii. art. “Célibat ecclésiastique”).
(G. G. Co.)
1W. Smith,Dict. of Greek and Roman Antiquities(3rd ed.), vol. ii. p. 44.2“In the 14th century, the city of Ilchi, in Chinese Tartary, possessed 14 monasteries, averaging 3000 devotees in each; while in Tibet, at the present time, there are in the vicinity of Lhassa 12 great monasteries, containing a population of 18,500 lamas. In Ladak the proportion of lamas to the laity is as 1 to 13, in Spiti 1 to 7, and in Burmah 1 to 30” (Lea i. 103).31 Cor. vii. 25 sq., ix. 5; 1 Tim. iii. 2, 11, 12; Titus i. 6; E. Vacandard inDict. de Théol. Cath.,s.v.“Célibat.”4This was a natural argument for the defenders of clerical celibacy even in far later times. St Bonaventura (d. 1274) puts this very strongly: “For if archbishops and bishops now had children, they would rob and plunder all the goods of the Church so that little or nothing would be left for the poor. For since they now heap up wealth and enrich nephews removed from them by almost incalculable degrees of affinity, what would they do if they had legitimate children?... Therefore the Holy Ghost in His providence hath removed this stumbling-block,” &c. &c. (In Sent.lib. iv. dist. xxxvii art. i. quaest. 3).5Hefele,Beitrage zur Kirchengesch. u.s.w.i. 139.6See the quotations in Lea i. 156. These prohibitions were renewed in the 13th and 14th centuries (ibid. i. 410).7Ratherius,Itinerarium, c. 5 (Migne,P.L.cxxxvi. col. 585). Gulielmus Apulus writes of southern Italy in 1059: “In these parts priests, deacons and the whole clergy were publicly married” (De Normann.lib. ii.).8Dom Pommeraye,S. Rotomag. Eccl. Concilia, pp. 56, 65; cf. similar instances on p. 315 of Dr A. Dresdner’sKultur-und Sittengeschichte d. italienischen Geistlichkeit im 10. und 11. Jhdt.(Breslau, 1890).9Opusc.xvii. praef. The saint’s evidence is carefully weighed by Dresdner (l.c.), especially on pp. 309 ff. and 321 ff.10Even Pope Innocent III. was compelled to decide that priests who had kept two or more concubines, successively or simultaneously, did not thereby incur the disabilities which attended digamists; or, in other words, that a layman who had contracted two lawful marriages and then proceeded to ordination on the death of his second wife, could be absolved only by the pope; whereas the concubinary priest, “as a man branded with simple fornication,” might receive a valid dispensation from his own bishop (Letter to archbishop of Lund in 1212.Regest.lib. xvi. ep. 118; Migne,P.L.ccxvi. col. 914). As the great canonist Gratian remarked on a similar decretal of Pope Pelagius, “Here is a case where lechery has more rights at law than has chastity” (Decret.p. i. dist. xxxiv. c. vii. note a).11The actual originator of this policy was Nicholas II., probably at Hildebrand’s suggestion; but the decree remained practically a dead letter until Gregory’s accession.12Peter Lombard,Sentent.lib. iv. dist. 13; Aquinas,Summa Theol.pars iii. Q. lxxxiii. art. 7, 9.13Labbe-Mansi,Concilia, vol. xix. col. 796 and xx. col. 724. Dr Lea is probably right in suggesting that it was a confused recollection of these decrees which prompted one of Cranmer’s judges to assure him that “his children were bondmen to the see of Canterbury.” Strype,Memorials of Cranmer, bk iii. c. 28 (ed. 1812, vol. i. p. 601).14Bonaventura,Libell. Apologet.quaest. i.; cf. his parallel treatiseQuare Fratres Minores praedicent. The first visitation of his friend Odo Rigaldi, archbishop of Rouen, shows that about 15% of the parish clergy in that diocese were notoriously incontinent (Regestrum Visitationum, ed. Bonnin, Rouen, 1852, pp. 17 ff.). Vacandard (loc. cit. p. 2087) appeals rather misleadingly to this record as proving the progress made during the half-century before Odo’s time. It is probable that there were many more offenders than these 15% known to the archbishop.15Alvarus Pelagius,De Planctu Ecclesiae, ed. 1517, f. 131a, col. 2; cf. f. 102b, col. 2; Hermann von der Hardt,Constantiensis Concilii, &c. vol. i. pars. viii. col. 428.16This more or less regular sale of licences by bishops and archdeacons flourished from the days of Gregory VII. to the 16th century; see index to Lea,s.v.“Licences.” Dr Lea has, however, omitted the most striking authority of all. Gascoigne, the most distinguished Oxford chancellor of his day, writing about 1450 of John de la Bere, then bishop of St David’s, says that he had refused to separate the clergy of his diocese from their concubines, giving publicly as his reason, “for then I your bishop should lose the 400 marks which I receive yearly in my diocese for the priests’ lemans” (Gascoigne,Lib. Ver.ed. Rogers, p. 36). Even Sir Thomas More, in his polemic against the Reformers, admitted that this concubinage was too often tolerated in Wales (English Works, ed. 1557, p. 231, cf. 619).17One of Dr Lea’s few serious mistakes is his acceptance of the spurious pamphlet in favour of priestly marriage which was attributed in the 11th century to St Ulrich of Augsburg (i. 171).18Janssen,Gesch. d. deutschen Volkes, 13th ed., vol. viii. pp. 423, 4, 9; 434; Lea ii. 195, 204. ff.19Lea (ii. 339. ff.) gives a long series of quotations to this effect from church synods and orthodox disciplinary writers of modern times.20Havelock Ellis,A Study of British Genius(London, 1904, p. 80), “Even if we compare the church with the other professions with which it is most usually classed, we find that the eminent children of the clergy considerably outnumber those of lawyers, doctors and army officers put together.” Mr Ellis points put, however, that “the clerical profession ... also produces more idiots than any other class.”
1W. Smith,Dict. of Greek and Roman Antiquities(3rd ed.), vol. ii. p. 44.
2“In the 14th century, the city of Ilchi, in Chinese Tartary, possessed 14 monasteries, averaging 3000 devotees in each; while in Tibet, at the present time, there are in the vicinity of Lhassa 12 great monasteries, containing a population of 18,500 lamas. In Ladak the proportion of lamas to the laity is as 1 to 13, in Spiti 1 to 7, and in Burmah 1 to 30” (Lea i. 103).
31 Cor. vii. 25 sq., ix. 5; 1 Tim. iii. 2, 11, 12; Titus i. 6; E. Vacandard inDict. de Théol. Cath.,s.v.“Célibat.”
4This was a natural argument for the defenders of clerical celibacy even in far later times. St Bonaventura (d. 1274) puts this very strongly: “For if archbishops and bishops now had children, they would rob and plunder all the goods of the Church so that little or nothing would be left for the poor. For since they now heap up wealth and enrich nephews removed from them by almost incalculable degrees of affinity, what would they do if they had legitimate children?... Therefore the Holy Ghost in His providence hath removed this stumbling-block,” &c. &c. (In Sent.lib. iv. dist. xxxvii art. i. quaest. 3).
5Hefele,Beitrage zur Kirchengesch. u.s.w.i. 139.
6See the quotations in Lea i. 156. These prohibitions were renewed in the 13th and 14th centuries (ibid. i. 410).
7Ratherius,Itinerarium, c. 5 (Migne,P.L.cxxxvi. col. 585). Gulielmus Apulus writes of southern Italy in 1059: “In these parts priests, deacons and the whole clergy were publicly married” (De Normann.lib. ii.).
8Dom Pommeraye,S. Rotomag. Eccl. Concilia, pp. 56, 65; cf. similar instances on p. 315 of Dr A. Dresdner’sKultur-und Sittengeschichte d. italienischen Geistlichkeit im 10. und 11. Jhdt.(Breslau, 1890).
9Opusc.xvii. praef. The saint’s evidence is carefully weighed by Dresdner (l.c.), especially on pp. 309 ff. and 321 ff.
10Even Pope Innocent III. was compelled to decide that priests who had kept two or more concubines, successively or simultaneously, did not thereby incur the disabilities which attended digamists; or, in other words, that a layman who had contracted two lawful marriages and then proceeded to ordination on the death of his second wife, could be absolved only by the pope; whereas the concubinary priest, “as a man branded with simple fornication,” might receive a valid dispensation from his own bishop (Letter to archbishop of Lund in 1212.Regest.lib. xvi. ep. 118; Migne,P.L.ccxvi. col. 914). As the great canonist Gratian remarked on a similar decretal of Pope Pelagius, “Here is a case where lechery has more rights at law than has chastity” (Decret.p. i. dist. xxxiv. c. vii. note a).
11The actual originator of this policy was Nicholas II., probably at Hildebrand’s suggestion; but the decree remained practically a dead letter until Gregory’s accession.
12Peter Lombard,Sentent.lib. iv. dist. 13; Aquinas,Summa Theol.pars iii. Q. lxxxiii. art. 7, 9.
13Labbe-Mansi,Concilia, vol. xix. col. 796 and xx. col. 724. Dr Lea is probably right in suggesting that it was a confused recollection of these decrees which prompted one of Cranmer’s judges to assure him that “his children were bondmen to the see of Canterbury.” Strype,Memorials of Cranmer, bk iii. c. 28 (ed. 1812, vol. i. p. 601).
14Bonaventura,Libell. Apologet.quaest. i.; cf. his parallel treatiseQuare Fratres Minores praedicent. The first visitation of his friend Odo Rigaldi, archbishop of Rouen, shows that about 15% of the parish clergy in that diocese were notoriously incontinent (Regestrum Visitationum, ed. Bonnin, Rouen, 1852, pp. 17 ff.). Vacandard (loc. cit. p. 2087) appeals rather misleadingly to this record as proving the progress made during the half-century before Odo’s time. It is probable that there were many more offenders than these 15% known to the archbishop.
15Alvarus Pelagius,De Planctu Ecclesiae, ed. 1517, f. 131a, col. 2; cf. f. 102b, col. 2; Hermann von der Hardt,Constantiensis Concilii, &c. vol. i. pars. viii. col. 428.
16This more or less regular sale of licences by bishops and archdeacons flourished from the days of Gregory VII. to the 16th century; see index to Lea,s.v.“Licences.” Dr Lea has, however, omitted the most striking authority of all. Gascoigne, the most distinguished Oxford chancellor of his day, writing about 1450 of John de la Bere, then bishop of St David’s, says that he had refused to separate the clergy of his diocese from their concubines, giving publicly as his reason, “for then I your bishop should lose the 400 marks which I receive yearly in my diocese for the priests’ lemans” (Gascoigne,Lib. Ver.ed. Rogers, p. 36). Even Sir Thomas More, in his polemic against the Reformers, admitted that this concubinage was too often tolerated in Wales (English Works, ed. 1557, p. 231, cf. 619).
17One of Dr Lea’s few serious mistakes is his acceptance of the spurious pamphlet in favour of priestly marriage which was attributed in the 11th century to St Ulrich of Augsburg (i. 171).
18Janssen,Gesch. d. deutschen Volkes, 13th ed., vol. viii. pp. 423, 4, 9; 434; Lea ii. 195, 204. ff.
19Lea (ii. 339. ff.) gives a long series of quotations to this effect from church synods and orthodox disciplinary writers of modern times.
20Havelock Ellis,A Study of British Genius(London, 1904, p. 80), “Even if we compare the church with the other professions with which it is most usually classed, we find that the eminent children of the clergy considerably outnumber those of lawyers, doctors and army officers put together.” Mr Ellis points put, however, that “the clerical profession ... also produces more idiots than any other class.”
CELL(from Lat.cella, probably from an Indo-Europeankal—seen in Lat.celare, to hide; another suggestion connects the word with Lat.cera, wax, taking the original meaning to refer to the honeycomb), in its earliest application a small detached room in a building, particularly a small monastic house (seeAbbey), generally in the country, belonging to large conventual buildings, and intended for change of air for the monks, as well as places to reside in to look after the lands, vassals, &c. Thus Tynemouth was a cell to St Albans; Ashwell, Herts, to Westminster Abbey. The term was also used of the small sleeping apartments of the monks, or a small apartment used by the anchorite or hermit. This use still survives in the application to the small separate chambers in a prison (q.v.) in which prisoners are confined. The word is applied to various small compartments which build up a compound structure such as a honeycomb, to the minute compartments in a tissue, &c. More particularly the word is used, in electrical science, of the single constituent compartments of a voltaic battery (q.v.), and in biology of the living units of protoplasm of which plants and animals are composed (seeCytology).
CELLA,in architecture, the Latin name for the sanctuary of a Roman temple, corresponding with the naos of the Greek temple. In the Etruscan temples, according to Vitruvius, there were three cellas, side by side; and in the temple of Venus built by Hadrian at Rome there were two cellas, both enclosed, however, in a single peristyle.
CELLARET(i.e.little cellar), strictly that portion of a sideboard which is used for holding bottles and decanters, so called from a cellar (which in general may be any underground unlighted apartment) being commonly used for keeping wine. Sometimes it is a drawer, divided into compartments lined with zinc, and sometimes a cupboard, but still an integral part of the sideboard. In the latter part of the 18th century, when the sideboard was in process of evolution from a side-table with drawers into the large and important piece of furniture which it eventually became, the cellaret was a detached receptacle. It was most commonly of mahogany or rosewood, many-sided or even octagonal, and occasionally oval, bound with broad bands of brass and lined with zinc partitions to hold the ice for cooling wine. Sometimes a tap was fixed in the lower part for drawing off the water from the melted ice. Cellarets were usually placed under the sideboard, and were, as a rule, handsome and well-proportioned; but as the artistic impulse which created the great 18th-century English school of furniture died away, their form grew debased, and under the influence of the English Empire fashion, which drew its inspiration from a bastard classicism, they assumed the shape of sarcophagi incongruously mounted with lions’ heads and claw-feet. Hepplewhite called them “gardes du vin”; they are now nearly always known as “wine-coolers.”
CELLE,a town of Germany, in the Prussian province of Hanover, on the left bank of the navigable Aller, near its junction with the Fuse and the Lachte, 23 m. N.E. of Hanover, on the main Lehrte-Hamburg railway. Pop. (1905) 21,400. The town has a Roman Catholic and five Protestant churches, among the latter the town-church with the burial vault of the dukes of Lüneburg-Celle. Here rest the remains of Sophia Dorothea, wife of the elector George of Hanover, afterwards George I. of England, and those of Caroline Matilda, the divorced wife of Christian VII. of Denmark and sister of George III. of England, who resided here from 1772 until her death in 1775. The most interesting building in Celle is the former ducal palace, begun in 1485 in Late Gothic style, but with extensive Renaissance additions of the close of the 17th century. The building of the court of appeal (Oberlandesgericht), with a valuable library of 60,000 volumes and many MSS., including a priceless copy of theSachsenspiegel, the museum and the hall of the estates (Landschaftshaus) are also worthy of notice. There are manufactures of woollen yarn, tobacco, biscuits, umbrellas and printers’ ink, and a lively trade is carried on in wax, honey, wool and timber. Celle is the seat of the court of appeal from the superior courts of Aurich, Detmold, Göttingen, Hanover, Hildesheim, Lüneburg, Osnabrück, Stade and Verden. Founded in 1292, the town was the residence of the dukes of Lüneburg-Celle, a cadet branch of the ducal house of Brunswick, from the 14th century until 1705.
See Dehning,Geschichte der Stadt Celle(Celle, 1891).
See Dehning,Geschichte der Stadt Celle(Celle, 1891).
CELLIER, ALFRED(1844-1891), English musical composer, was born at Hackney on the 1st of December 1844. From 1855 to 1860 he was a chorister at the Chapel Royal, St James’s, under the Rev. Thomas Helmore, where Arthur Sullivan was one of his youthful colleagues. His first appointment was that of organist at All Saints’ church, Blackheath (1862). In 1866 he succeeded Dr Chipp as director of the Ulster Hall concerts, Belfast, at the same time acting as conductor of the Belfast Philharmonic Society. In 1868 he returned to London as organist of St Alban’s, Holborn. From 1871 to 1875 he was conductor at the Prince’s theatre, Manchester; and from 1877 to 1879 at various London theatres. During this period he composed many comic operas and operettas, of which the most successful wasThe Sultan of Mocha, which was produced at Manchester in 1874, in London at the St James’s theatre in 1876, and revived at the Strand theatre in 1887. In 1880 Cellier visited America, producing a musical version of Longfellow’sMasque of Pandoraat Boston (1881). In 1883 his setting of Gray’sElegyin the form of a cantata was produced at the Leeds Festival. In 1886 he won the great success of his life inDorothy, a comic opera written to a libretto by B.C. Stephenson, which was produced at the Gaiety theatre on the 25th of September 1886, and, transferred first to the Prince of Wales theatre and subsequently to the Lyric theatre, ran until April 1889.Doris(1889), andThe Mountebanks, which was produced in January 1892, a few days after the composer’s death, were less successful. Cellier owed much to the influence of Sir Arthur Sullivan. He had little of the latter’s humour and vivacity, but he was a fertile melodist, and his writing is invariably distinguished by elegance and refinement. He died in London on the 28th of December 1891.
CELLINI, BENVENUTO(1500-1571), Italian artist, metal worker and sculptor, was born in Florence, where his family, originally landowners in the Val d’Ambra, had for three generations been settled. His father, Giovanni Cellini, was a musician and artificer of musical instruments; he married Maria Lisabetta Granacci, and eighteen years elapsed before they had any progeny. Benvenuto (meaning “Welcome”) was the third child. The father destined him for the same profession as himself, and endeavoured to thwart his inclination for design and metal work. When he had reached the age of fifteen his youthful predilection had become too strong to be resisted, and his father reluctantly gave consent to his being apprenticed to a goldsmith, Antonio di Sandro, named Marcone. He had already attracted some notice in his native place, when, being implicated in a fray with some of his companions, he was banished for six months to Siena, where he worked for Francesco Castoro, a goldsmith; from thence he removed to Bologna, where he became a more accomplished flute-player and made progress in the goldsmith’s art. After visiting Pisa, and after twice resettling for a while in Florence (where he was visited by the sculptor Torrigiano, who unsuccessfully suggested his accompanying him to England), he decamped to Rome, aged nineteen. His first attempt at his craft here was a silver casket, followed by some silver candlesticks, and later by a vase for the bishop of Salamanca, which introduced him to the favourable notice of Pope Clement VII.; likewise at a later date one of his celebrated works, the gold medallion of “Leda and the Swan,”—the head and torso of Leda cut in hard stone—executed for Gonfaloniere Gabbriello Cesarino, which is now in the Vienna museum; he also reverted to music, practised flute-playing, and was appointed one of the pope’s court-musicians. In the attack upon Rome by the constable de Bourbon, which occurred immediately after, in 1527, the bravery and address of Cellini proved of signal serviceto the pontiff; if we may believe his own accounts, his was the very hand which shot the Bourbon dead, and he afterwards killed Philibert, prince of Orange. His exploits paved the way for a reconciliation with the Florentine magistrates, and his return shortly after to his native place. Here he assiduously devoted himself to the execution of medals, the most famous of which (executed a short while later) are “Hercules and the Nemean Lion,” in gold repoussé work, and “Atlas supporting the Sphere,” in chased gold, the latter eventually falling into the possession of Francis I. From Florence he went to the court of the duke of Mantua, and thence again to Florence and to Rome, where he was employed not only in the working of jewelry, but also in the execution of dies for private medals and for the papal mint. Here in 1529 he avenged a brother’s death by slaying the slayer; and shortly afterwards had to flee to Naples to shelter himself from the consequences of an affray with a notary, Ser Benedetto, whom he wounded. Through the influence of several of the cardinals he obtained a pardon; and on the elevation of Paul III. to the pontifical throne he was reinstated in his former position of favour, notwithstanding a fresh homicide of a goldsmith which he had committed more by accident than of malice prepense in the interregnum. Once more the plots of Pierluigi Farnese, a natural son of Paul III., led to his retreat from Rome to Florence and Venice, and once more he was restored with greater honour than before. On returning from a visit to the court of Francis I., being now aged thirty-seven, he was imprisoned on a charge (apparently false) of having embezzled during the war the gems of the pontifical tiara; he remained some while confined in the castle of Sant’ Angelo, escaped, was recaptured, and treated with great severity, and was in daily expectation of death on the scaffold. At last, however, he was released at the intercession of Pierluigi’s wife, and more especially of the Cardinal d’ Este of Ferrara, to whom he presented a splendid cup. For a while after this he worked at the court of Francis I. at Fontainebleau and in Paris; but he considered the duchesse d’Étampes to be set against him, and the intrigues of the king’s favourites, whom he would not stoop to conciliate and could not venture to silence by the sword, as he had silenced his enemies in Rome, led him, after about five years of laborious and sumptuous work, and of continually-recurring jealousies and violences, to retire in 1545 in disgust to Florence, where he employed his time in works of art, and exasperated his temper in rivalries with the uneasy-natured sculptor Baccio Bandinelli. The first collision between the two had occurred several years before when Pope Clement VII. commissioned Cellini to mint his coinage. Now, in an altercation before Duke Cosimo, Bandinelli insultingly stigmatized Benvenuto as guilty of gross immorality; in his autobiography Cellini rather repels than denies the charge, but he certainly repels it with demonstrative and grotesque vivacity. Two somewhat similar charges had been made ere this: one in Paris, which he braved out in court—the other, in Florence, was a mere private quarrel, and perhaps undeserving of attention. During the war with Siena Cellini was appointed to strengthen the defences of his native city, and, though rather shabbily treated by his ducal patrons, he continued to gain the admiration of his fellow-citizens by the magnificent works which he produced. He died in Florence in 1571, unmarried, and leaving no posterity, and was buried with great pomp in the church of the Annunziata. He had supported in Florence a widowed sister and her six daughters.
Besides the works in gold and silver which have been adverted to, Cellini executed several pieces of sculpture on a grander scale. The most distinguished of these is the bronze group of “Perseus holding the head of Medusa,” a work (first suggested by Duke Cosimo de’ Medici) now in the Loggia dei Lanzi at Florence, full of the fire of genius and the grandeur of a terrible beauty, one of the most typical and unforgettable monuments of the Italian Renaissance. The casting of this great work gave Cellini the utmost trouble and anxiety; and its completion was hailed with rapturous homage from all parts of Italy. The original relief from the foot of the pedestal—Perseus and Andromeda—is in the Bargello, and replaced by a cast.
Not less characteristic of its splendidly gifted and barbarically untameable author are the autobiographical memoirs which he composed, beginning them in Florence in 1558,—a production of the utmost energy, directness and racy animation, setting forth one of the most singular careers in all the annals of fine art. His amours and hatreds, his passions and delights, his love of the sumptuous and the exquisite in art, his self-applause and self-assertion, running now and again into extravagances which it is impossible to credit, and difficult to set down as strictly conscious falsehoods, make this one of the most singular and fascinating books in existence. Here we read, not only of the strange and varied adventures of which we have presented a hasty sketch, but of the devout complacency with which Cellini could contemplate a satisfactorily achieved homicide; of the legion of devils which he and a conjuror evoked in the Colosseum, after one of his not innumerous mistresses had been spirited away from him by her mother; of the marvellous halo of light which he found surrounding his head at dawn and twilight after his Roman imprisonment, and his supernatural visions and angelic protection during that adversity; and of his being poisoned on two several occasions. If he is unmeasured in abusing some people, he is also unlimited in praising others. The autobiography has been translated into English by Thomas Roscoe, by J.A. Symonds, and by A. Macdonald. Cellini also wrote treatises on the goldsmith’s art, on sculpture, and on design (translated by C.R. Ashbee, 1899).
Among his works of art not already mentioned, many of which have perished, were a colossal Mars for a fountain at Fontainebleau and the bronzes of the doorway, coins for the Papal and Florentine states, a Jupiter in silver of life size, and a bronze bust of Bindo Altoviti. The works of decorative art are, speaking broadly, rather florid than chastened in style.
In addition to the bronze statue of Perseus and the medallions already referred to, the works of art in existence to-day executed by him are the celebrated salt-cellar made for Francis I. at Vienna; a medallion of Clement VII. in commemoration of the peace between the Christian princes, 1530, with a bust of the pope on the reverse and a figure of Peace setting fire to a heap of arms in front of the temple of Janus, signed with the artist’s name; a medal of Francis I. with his portrait, also signed; and a medal of Cardinal Pietro Bembo. Cellini, while employed at the papal mint at Rome during the papacy of Clement VII. and later of Paul III., executed the dies of several coins and medals, some of which still survive at this now defunct mint. He was also in the service of Alessandro de’ Medici, first duke of Florence, for whom he executed in 1535 a forty-soldi piece with a bust of the duke on one side and standing figures of the saints Cosmo and Damian on the other. Some connoisseurs attribute to his hand several plaques, “Jupiter crushing the Giants,” “Fight between Perseus and Phinaeus,” a Dog, &c.
The important works which have perished include the uncompleted chalice intended for Clement VII.; a gold cover for a prayer-book as a gift from Pope Paul III. to Charles V.,—both described at length in his autobiography; large silver statues of Jupiter, Vulcan and Mars, wrought for Francis I. during his sojourn in Paris; a bust of Julius Caesar; and a silver cup for the cardinal of Ferrara. The magnificent gold “button,” or morse, made by Cellini for the cope of Clement VII., the competition for which is so graphically described in his autobiography, appears to have been sacrificed by Pius VI., with many other priceless specimens of the goldsmith’s art, in furnishing the indemnity of 30,000,000 francs demanded by Napoleon at the conclusion of the campaign against the States of the Church in 1797. According to the terms of the treaty, the pope was permitted to pay a third of that sum in plate and jewels. Fortunately there are in the print room of the British Museum three water-colour drawings of this splendid morse by F. Bertoli, done at the instance of an Englishman named Talman in the first half of the 18th century. The obverse and reverse, as well as the rim, are drawn full size, and moreover the morse with the precious stones set therein, including a diamond then considered the second largest in the world, is fully described.
Bibliography.—The autobiography already named is the foundation of most of the works written concerning Cellini’s life. See alsoCellini, His Times and Contemporaries, by “the Author of the Life of Sir Kenelm Digby” (1899); L. Dimier,Cellini à la cour de France(1898); Eugène Plon,Cellini, orfèvre, médailleur, &c.(1883); Bolzenthal,Skizzen zur Kunstgeschichte der modernen Medaillen-Arbeit 1429-1840(Berlin, 1840); A. Armand,Les Médailleurs italiens des XVe et XVIe siècles(3 vols., Paris, 1883-1887); Dr Francesco Tassi,Vita di Benvenuto Cellini(Firenze, 1829),Vita di Benvenuto Cellini scritta da lui medisimo(1832); E. Babelon,La Gravure en pierres fines(Paris, 1894); A. Heiss,Les Médailleurs florentins(Paris, 1887); J. Friedländer,Die italienischen Schaumünzen des fünfzehnten Jahrhunderts(Berlin, 1880-1882); N. Rondot,Les Médailleurs lyonnais(Mâcon, 1897); Dr Julius Cahn,Medaillen und Plaketten der Sammlung W.P. Metzler(Frankfort-on-Main, 1898); Molinier,Les Plaquettes; I.B. Supino,Il Medagliere Mediceo nel R. Museo Nazionale di Firenze(Florence, 1899);L’Arte di Benvenuto Cellini(Florence, 1901); C. von Fabriczy,Medaillen der italienischen Renaissance(Leipzig); L. Forrer,Biographical Dictionary of Medallists, &c.(London, 1904), &c.
Bibliography.—The autobiography already named is the foundation of most of the works written concerning Cellini’s life. See alsoCellini, His Times and Contemporaries, by “the Author of the Life of Sir Kenelm Digby” (1899); L. Dimier,Cellini à la cour de France(1898); Eugène Plon,Cellini, orfèvre, médailleur, &c.(1883); Bolzenthal,Skizzen zur Kunstgeschichte der modernen Medaillen-Arbeit 1429-1840(Berlin, 1840); A. Armand,Les Médailleurs italiens des XVe et XVIe siècles(3 vols., Paris, 1883-1887); Dr Francesco Tassi,Vita di Benvenuto Cellini(Firenze, 1829),Vita di Benvenuto Cellini scritta da lui medisimo(1832); E. Babelon,La Gravure en pierres fines(Paris, 1894); A. Heiss,Les Médailleurs florentins(Paris, 1887); J. Friedländer,Die italienischen Schaumünzen des fünfzehnten Jahrhunderts(Berlin, 1880-1882); N. Rondot,Les Médailleurs lyonnais(Mâcon, 1897); Dr Julius Cahn,Medaillen und Plaketten der Sammlung W.P. Metzler(Frankfort-on-Main, 1898); Molinier,Les Plaquettes; I.B. Supino,Il Medagliere Mediceo nel R. Museo Nazionale di Firenze(Florence, 1899);L’Arte di Benvenuto Cellini(Florence, 1901); C. von Fabriczy,Medaillen der italienischen Renaissance(Leipzig); L. Forrer,Biographical Dictionary of Medallists, &c.(London, 1904), &c.
(W. M. R.; E. A. J.)
CELLULOSE,the name given to both an individual—cellulose proper, in the restricted sense of a chemical individual—and to a group of substances, the celluloses or cellulose group, which constitute in infinitely varied forms the containing envelope of the plant cell. They are complex carbohydrates, or “saccharo-colloids” (Tollens), and are resolved by ultimate hydrolysis into monoses. The typical cellulose is represented by the empirical formula C6H10O5, identical with that of starch, with which it has many chemical analogies as well as physiological correlations. The representative “cellulose” is the main constituent of the cotton fibre substance, and is obtainable by treating the raw fibre with boiling dilute alkalis, followed by chlorine gas or bromine water, or simply by alkaline oxidants. The cellulose thus purified is further treated with dilute acids, and then exhaustively with alcohol and ether. Chemical filter-paper (Swedish) is practically pure cellulose, the final purification consisting in exhaustive treatment with hydrofluoric acid to remove silicious inorganic residues. The “cellulose” group, however, comprises a series of substances which, while presenting the characters generally similar to those of cotton cellulose, also exhibit marked divergences. The resemblances are maintained in their synthetical reactions; but reactions involving the decomposition of the complex show many variations. For example, cotton cellulose is difficultly hydrolysed; other celluloses are more or less readily split up by dilute acids, the extreme members readily yielding sugars: the hexoses—dextrose, mannose and galactose; and the pentoses—xylose and arabinose; these less resistant cell-wall constituents are termed hemi-celluloses.
The celluloses proper are essentially non-nitrogenous, though originating in the cell protoplasm. The cell-walls of the lower cryptogams, similarly purified, retain a notable proportion—2.0-4.0%—of constitutional nitrogen. When hydrolysed these fungoid celluloses yield, in addition to monoses, glucosamine and acetic acid. The celluloses of the phanerogams are generally associated, in a degree ranging from physical mixture to chemical union, with other complicated substances, constituting the “compound celluloses.” The nature of the associated groups affords a convenient classification into pecto-celluloses, ligno-celluloses and cuto-celluloses.Pecto-cellulosesare so named because the associated substances—carbohydrates, together with their oxidation products,i.e.containing either two carbonyls (CO) in the unit group or carboxyl (CO·OH) groups in a complex—are readily hydrolysed by weak acids to the gelatinous “pectic acids” or their salts.Ligno-cellulosesare the substances of lignified tissue, the non-cellulose constituents of which are characterized by the presence of benzenoid and furfuroid groups; and although essentially complex, they may be regarded as homogeneous, and are conveniently grouped under the namelignone. The lignone complex reacts, by its unsaturated groups, with the halogens. It is a complex containing but little hydroxyl; and is of relatively high carbon percentage (55.0-57.0%).Cuto-cellulosespredominate in the protective coatings of plant organs, and are characterized by constituent groups, the decomposition products of which are compounds of the fatty series, and also wax alcohols, acids, cholesterols, &c.
The typical pecto-cellulose is the flax fibre,i.e.the bast fibre of the flax plant (Linum usitatissimum), as it occurs in the plant, or as the commercial textile fibre in its raw state. Rhea, or ramie, is another leading textile fibre in which the cellulose occurs associated with alkali-soluble colloidal carbohydrates. Pecto-celluloses are found in the stems of the Gramineae (cereal straws, esparto), and in the fibro-vascular bundles of monocotyledons used as textile and rope-making fibres. They are the chief constituents of the fleshy parenchyma of fruits, tubers, rhizomes. Ligno-celluloses find their chemical representative in the jute fibre. They constitute the woods, and are therefore of the widest distribution and the highest industrial utility. It is important to note that a complex having all the chemical characteristics of a ligno-cellulose occurs in a soluble colloidal form in the juice of the white currant. The formation of ligno-cellulose is the chemical equivalent of the morphological change of the plant cell known as “lignification.” The topical cuto-celluloses are the epidermal tissues of all growing plants or organs, which are easily detached from the underlying tissues which it is their function to protect. To subserve this function, they are extremely resistant to the attack of reagents. The associated groups are mostly of the normal saturated series, and of very high molecular weight.
Cellulose and Botanical Science.—The elaboration of cellulose,i.e.of the cell walls, and its morphological and physiological aspects are discussed in the articlesPlants:Physiology, Anatomy: andCytology; while in the articleCoalthe part played by cellulose in the formation of these deposits receives treatment: here we may deal with its general relation to agriculture. In the analysis of fodder plants and other vegetable produce, the residue obtained after successive acid and alkaline hydrolysis is the “crude fibre” of the agricultural chemist, and is generally taken as a measure of the actual cellulose contents of the raw material. We give in tabular form the average percentage of crude fibre in typical food-stuffs and agricultural produce:—
Seeds
Fodder Crops
The above figures have a purely empirical value, since they represent a complicated mixture of various residues derived from the celluloses and compound celluloses. This mixture may be further resolved, and by special quantitative methods the proportions of actual cellulose, ligno-cellulose and cuto-celluloses estimated (J. König,Ber., 1906, 39, p. 3564). The figures are taken as an inverse measure of digestibility; at the same time it has been established that this group of relatively indigestible food constituents are more or less digestible and assimilable as flesh and fat producers. The percentage or coefficient of digestibility of the celluloses of the more important food-stuffs—green fodder, hay, straw and grains—varies from 20 to 75%. It has also been established that their physiological efficiency is, under certain conditions, quite equal to that of starch.
It must also be borne in mind that the indigestible food residues, as finally voided by the animal, have played an important mechanical part as an aid to digestion of those constituents more readily attacked in the digestive tract of animals. They are further an important factor of the agricultural cycle. Returned to the soil as “farm-yard manure,” mixed with other cellulosic matter which has served as litter, they add “fibre” to the soil and, as a mechanical diluent of the mineral soil components, maintain this in a more open condition, penetrable by the atmospheric gases, and promoting distribution of moisture. Further by breaking down, with production of “humus,” a complex of colloidal “unsaturated” bodies of acid function, they fulfil important chemical functions by interaction with the mineral soil constituents.
Chemistry of Cellulose.—Purified cotton cellulose, which is the definitive prototype of the cellulose group or series, is a complex of monoses or their “residues.” It is resolved by solution in sulphuric acid and subsequent hydrolysis of the esters thus produced into dextrose. This fundamental fact with its elementary composition, most simply expressed by the formula C6H10O5, has caused it to be regarded as a polyanhydride of dextrose. Forming, as it does, simple esters in the ratio of the reacting hydroxyls 3OH: C6H10O5, and taking into account its direct converson into ω-brom-methyl furfural (Fenton) a constitutional formula has been proposed by A.G. Green (Zeit. Farb. Textil Chem.3, pp. 97 and 309 (1904)), which is a useful generalization of its reactions, and its ultimate relations to the simpler carbohydrates, viz.,Green considers, moreover, that a group thus formulated may consistently represent the actual dimensions of the reacting unit, but that unit of larger dimensions, if postulated, is easily derived from the above by oxygen linkings.
From another point of view the unit group has been formulated asthe main linking of such units in the complex taking place as between their respective CO and CH2groups in the alternative enolic form CH—C(OH). This view gives expression to the genetic relations of the celluloses to the ligno-celluloses, to the tendency to carbon condensation as in the formation of coals, and pseudo-carbons, to the relative resistance of cellulose to hydrolysis, and its other points of differentiation from starch, and more particularly to the ketonic character of its carbonyl (CO) groups, which is also more in harmony with the experimental facts established by Fenton as to the production of methyl furfural.
The probability, however, is that no simple molecular formula adequately represents the constitution of cellulose as it actually exists or indeed reacts. On the other hand, it has been suggested that cellulose is to be regarded as representing a condition of matter analogous to that of a saline electrolyte in solution,i.e.as a complex of molecular aggregates, and of residues (of monose groups) having distinct and opposite polarities; such a complex is essentially labile and its configuration will change progressively under reaction. The exposition of this view is the subject of a publication by Cross and Bevan (Researches on Cellulose, ii. 1906). The main purpose is to give full effect to the colloidal characteristics of cellulose and its derivatives, with reference to the modern theory of the colloidal state as involving a particular internal equilibrium of amphoteric electrolytes.
The typical cellulose is a white fibrous substance familiar to us in the various forms of bleached cotton. Other fibrous celluloses are equally characteristic as to form and appearance,e.g.bleached flax, hemp, ramie. It is hygroscopic, absorbing 6 to 7% its weight of moisture from the air. When dry, it is an electrical insulator, and has a specific inductive capacity of about 7: when wetted it is a conductor, and manifests electrolytic phenomena.1It is insoluble in water and in the ordinary solvents; it dissolves, however, in a 40-50% solution of zinc chloride, and in ammoniacal solutions of copper oxide (3% CuO, 15% NH3): from these solutions it is obtained as a highly hydrated, gelatinous precipitate, from the former by dilution or addition of alcohol, from the latter by acidification; these solutions have important industrial application. Projected or drawn into a precipitating solution they may be solidified continuously to threads of various, but controlled dimensions: the regenerated cellulose, now amorphous, in its finer dimensions is known as artificial silk or lustra-cellulose. These forms of cellulose retain the general characters of the original fibrous and “natural” celluloses. In composition they differ somewhat by combination with water (of hydration), which they retain in the air-dry condition. They also further combine with an increased proportion of atmospheric moisture, viz. up to 10-11% of their weight.
Derivatives.—Important derivatives are the esters or ethereal salts of both inorganic and organic acids, cellulose behaving as an alcohol, the highest esters indicating that it reacts as a trihydric alcohol of the formula n[C6H7O2(OH)3]. The nitrates result by the action of concentrated nitric acid, either alone or in the presence of sulphuric acid: the normal dinitrate represents a definite stage in the series of nitrates, and the ester at this point manifests the important property of solubility in various alcoholic solvents, notably ether-alcohol. Such nitrates are the basis of collodion, of artificial silk by the processes of Chardonnet and Lehner, and of celluloid or xylonite. Higher nitrates are also obtainable up to the limit of the trinitrate, which is insoluble in ether or alcohol, but is soluble in nitroglycerin, nitrobenzene and other solvents. These higher nitrates are the basis of the most important modern explosives.
Cellulose reacts directly with acetic anhydride to form low esters; in the presence of sulphuric acid the reaction proceeds to higher limits; the triacetate is soluble in chloroform. The acid sulphuric ester, C6H8O3(SO4H)2, is obtained by the action of sulphuric acid, but its relation to the original cellulose is doubtful. The monobenzoate and dibenzoate are formed by benzoyl chloride reacting on alkali-cellulose (see below). Cellulose xanthates are obtained from carbon bisulphide and alkali-cellulose; these are water soluble derivatives and the basis of “viscose,” and of important industries. Mixed esters—-aceto-sulphate, aceto-benzoate, nitrobenzoyl nitrates, aceto-nitro-sulphates—have also been investigated.
Cellulose (cotton), when treated with a 15-20% caustic soda solution, gives the compound C6H10O5·H2O·2NaOH, alkali-cellulose, the original riband-like form with reticulated walls of the cellulose being transformed into a smooth-walled cylinder. The structural changes in the ultimate fibre determine very considerable changes in the dimensions of fabrics so treated. The reactions and structural changes were investigated by J. Mercer, and are known generally as “mercerization.” In recent years a very large industry in “mercerized” fabrics (cotton) has resulted from the observation that if the shrinkages of the yarns and fabrics be antagonized by mechanical means, a very high lustre is developed.
Similar, but less definite compounds, are formed with the oxides of lead, manganese, barium, iron, aluminium and chromium. These derivatives, which also find industrial applications in the dyeing and printing of fabrics, differ but little inappearance from the original cellulose, and are without influence on its essential characteristics.
Decompositions.—Hydrolysis:—By solution in sulphuric acid followed by dilution and boiling the diluted solution cellulose hydrolyses to fermentable sugars; this reaction is utilized industrially in the manufacture of glucose from rags. Hydrochloric acid produces a friable mass of “hydrocellulose,” probably C12H22O11, insoluble in water, but readily attacked by alkalis, with the production of soluble derivatives; some dextrose is formed in the original reaction. Hydrobromic acid in ethereal solution gives furfurane derivatives. Cold dilute acids have no perceptible action on cellulose. The actions of such acids are an important auxiliary to bleaching, dyeing and printing processes, but they require careful limitation in respect of concentration and temperature. Cellulose is extremely resistant to the action of dilute alkalis: a 1-2% solution of sodium hydrate having little action at temperatures up to 150° hence the use of caustic soda, soda ash and sodium silicate in bleaching processes,i.e.for the elimination of the non-cellulose components of the raw fibres. Oxidation in acid solutions gives compounds classed as “oxycelluloses,” insoluble in water, but more or less soluble in alkalis; continued oxidation gives formic, acetic and carbonic acids. Oxidation in alkaline solution is more easily controlled and limited; solutions of bleaching powder, or more generally of alkaline hydrochlorites, receive industrial application in oxidizing the coloured impurities of the fibre, or residues left after more or less severe alkali treatments, leaving the cellulose practically unaffected. This, however, is obviously a question of conditions: this group of oxidants also oxidize to oxycellulose, and under more severe conditions to acid products,e.g.oxalic and carbonic acids. Certain bacteria also induce decompositions which are resolutions into ultimate products of the lowest molecular dimensions, as hydrogen, carbon dioxide, methane, acetic acid and butyric acid (Omeliansky) (Handb. Techn. Mykologie[F. Lafar] pp. 245-268), but generally the cellulose complex is extremely resistant to the organic ferments. Cellulose burns with a luminous flame to carbon dioxide and water; dry distillation gives a complicated mixture of gaseous and liquid products and a residue of charcoal or pseudo-carbon. Chromic acid in sulphuric acid solutions effects a complete oxidation,i.e.combustion to water and carbonic acid.
Ligno-celluloses.—These compounds have many of the characteristics of the cellulose esters; they are in effect ethereal compounds of cellulose and the quinonoid lignone complex, and the combination resists hydrolysis by weak alkalis or acids. The cellulose varies in amount from 80 to 50%, and the lignone varies inversely as the degree of lignification, that is, from the lignified bast fibre of annuals, of which jute is a type, to the dense tissues of the perennial dicotyledonous woods, typified by the beech. The empirical formula of the lignone complex varies from C19H22O9(jute) to C26H30O10(pine wood). In certain reactions the non-cellulose or lignone constituents are selectively converted into soluble derivatives, and may be separated as such from the cellulose which is left; for example, chlorination gives products soluble in sodium sulphite solution, by the combination of unsaturated groups of the lignone with the halogen, while digestion with bisulphite solutions at elevated temperatures (140°-160°) gives soluble sulphonated derivatives. This last reaction is employed industrially in the preparation of cellulose for paper-making from coniferous woods. These reactions are “quantitative” since they depend upon well-defined constitutional features of the lignone complex, and the resolution of the ligno-cellulose takes place with no further change in the lignone than the synthetical combination with the substituting groups. The constituent groups of the lignone specifically reacting are of benzenoid type of the probable formdeduced from the similarity of the chlorinated derivatives to mairogallol, the product of the action of chlorine on pyrogallol in acetic acid solution (A. Hantzsch,Ber.20, p. 2033). The complex contains methoxy (OCH3) groups. There is also present a residue which is readily broken down by oxidizing agents, and indeed by simple hydrolysis, to acetic acid. Another important group of actual constituents are pentosanes—partially isolated as “wood gum” by solution in alkalis—and furfural derivatives (hydroxy furfurals) derived from these. The actual constitutional relationships of these main groups, as well as the localization of the methoxy groups, are still problematical.
Certain colour reactions are characteristic, though they are in some cases reactions of certain constituents invariably present in the natural forms of the ligno-cellulose; which may be removed without affecting the essential character of the lignone complex. Aniline salts generally give a yellow coloration, dimethyl-para-phenylenediamine gives a deep red coloration, phloroglucin in hydrochloric acid gives a crimson coloration. Reactions more definitely characteristic of the lignone are:—ferric ferrocyanide, which is taken up and transformed into Prussian blue throughout the fibre, without affecting its structure, although there may be as much as a 50% gain in weight; iodine in potassium iodide solution gives a deep brown colour due to absorption of the halogen, a reaction which admits of quantitative application,i.e.as a measure of the proportion of ligno-cellulose in a fibrous mixture; nitric acid gives a deep orange yellow coloration; digested with the dilute acid (5-10% HNO3) at 50° the ligno-celluloses are entirely resolved, the lignone complex being attacked and dissolved in the form of nitroso-ketonic acids, which, on continued heating, are finally resolved to oxalic, acetic, formic and carbonic acids.
Derivatives of Ligno-cellulose.—By reaction with chlorine jute yields the derivative C19H18Cl4O9, soluble in alcohol, and in acetic acid; this derivative has the reactions of a quinone chloride. By reaction with sodium sulphite it is converted into a hydroquinone sulphonate of deep purple colour. The reaction of the ligno-celluloses (pine wood) with the bisulphites yields the soluble derivatives of the general formula C26H29O9SO3H (containing two OCH3groups). Jute reacts with nitric acid in presence of sulphuric acid to form nitrates; and with acetic anhydride to form low acetates. It reacts with alkaline hydrates with structural changes similar to those obtained with cotton; and by the further action of benzoyl chloride and of carbon bisulphide upon the resulting compounds there result the corresponding benzoates and xanthates respectively. But these synthetical derivatives are mixtures of cellulose and lignone derivatives, and so far of merely theoretical interest.
Decompositions of Ligno-cellulose.—In addition to the specific resolutions above described which depend upon the distinctive chemical characters of the cellulose and lignone respectively, the following may be noted: to simple hydrolytic agents the two groups are equally resistant, therefore by boiling with dilute acids or alkalis the groups are attackedpari passu. Weak oxidants may also be used as bleaching agents to remove coloured by-products without seriously attacking the ligno-cellulose, which is obtained in its bleached form. Nitric acid of all strengths effects complete resolution. Chromic acid in dilute solutions combines with the lignone complex, but in presence of hydrolysing acids total oxidation of the lignone is determined. The principal products are oxalic, carbonic, formic and acetic acids. This reaction is an index of constitution. Generally, the lignone is attacked under many conditions and by many reagents which are without action upon cellulose, by virtue of its unsaturated constitution, and its acid and aldehydic residues.
Cuto-cellulose.—A typical cuto-cellulose is the cuticle (peel) of the apple which, when purified by repeated hydrolytic treatment and finally by alcohol and ether, gives a product of the composition C = 75.66%, H = 11.37%, O = 14.97%. Hydrolysis by strong alkalis gives stearo-cutic acid, C28H48O4, and oleo-cutic acid, C14H20O4(Frémy). Cork is a complex mixture containing various compound celluloses: extraction with alcohol removes certain fatty alcohols and acids, and aromatic derivatives related to tannic acid; the residue is probably a mixture of cellulose, ligno-cellulose, cerin, C20H32O and suberin; the latter yieldsstearic acid, C18H36O2and the acid C22H42O3. The cuto-celluloses have been only superficially investigated, and, with the exception of cork, are of but little direct industrial importance.
Industrial Uses of Cellulose.—The applications of cellulose to the necessities of human life, infinitely varied in kind as they are colossal in magnitude, depend upon two groups of qualities or properties, (1) structural, (2) chemical. The manufactures of vegetable textiles and of paper are based upon the fibrous forms of the naturally occurring celluloses, together with such structural qualities as are expressed in the terms strength, elasticity, specific gravity. As regards chemical properties, those which come into play are chiefly the negative quality of resistance to chemical change; this is obviously a primary factor of value in enabling fabrics to withstand wear and tear, contact with atmospheric oxygen and water, and such chemical treatments as laundrying; positive chemical properties are brought into play in the auxiliary processes of dyeing, printing, and the treatment and preparation in connexion with these. Staple textiles of this group are cotton, flax, hemp and jute; other fibres are used in rope-making and brush-making industries. These subjects are treated in special articles under their own headings and in the articleFibres. The course of industrial development in the 19th century has been one of enormous expansion in use and considerable refinement in methods of preparation and manufacture. Efforts to introduce new forms of cellulose have had little result. Rhea or ramie has been a favourite subject of investigation; the industry has been introduced into England, and doubtless its development is only a question of time, as on the continent of Europe the production of rhea yarns is well established, though it is still only a relatively small trade—probably two or three tons a day total production. The paper trade has required to seek new sources of cellulose, in consequence of the enormous expansion of the uses of paper. Important phases of development were: (1) in the period of 1860 to 1870, the introduction of esparto, which has risen to a consumption of 250,000 tons a year in the United Kingdom, at which figure it remains fairly steady; (2) the decade 1870 to 1880, which saw the development of the manufacture of cellulose from coniferous woods, and this industry now furnishes a staple of world-wide consumption, though the industry is necessarily localized in countries where the coniferous woods are available in large quantities. As a development of the paper industry we must mention the manufacture of paper textiles, based upon the production of pulp yarns. Paper pulps are worked into flat strips, which are then rolled into cylindrical form, and by a final twisting process a yarn is produced sufficiently strong to be employed in weaving.
What we may call the special cellulose industries depend upon specific chemical properties of cellulose, partly intrinsic, partly belonging to the derivatives such as the esters. Thus the cellulose nitrates are the bases of our modern high explosives, as well as those now used for military purposes. Their use has been steadily developed and perfected since the middle of the 19th century. The industries in celluloid, xylonite, &c., also depend upon the nitric esters of cellulose, and the plastic state which they assume when treated with solvent liquids, such as alcohol, amyl acetate, camphor and other auxiliaries, in which state they can be readily moulded and fashioned at will. They have taken an important place as structural materials both in useful and artistic applications. The acetates of cellulose have recently been perfected, and are used in coating fine wires for electrical purposes, especially in instrument-making; this use depends upon their electrical properties of high insulation and low inductive capacity. Hydrated forms of cellulose, which result from treatment with various reagents, are the bases of the following industries: vegetable parchment results from the action of sulphuric acid upon cellulose (cotton) in the form of paper, followed by that of water, which precipitates the partially colloidalized cellulose. This industry is carried out on “continuous” machinery, the cellulose, in the form of paper, being treated in rolls. Vulcanized fibre is produced by similar processes, as for instance by treating paper with zinc chloride solvents and cementing together a number of sheets when in the colloidal hydrated state; the goods are exhaustively washed to remove, last traces of soluble electrolytes; this is necessary, as the product is used for electrical insulation. The solvent action of cupro-ammonium is used in treating cellulose goods, cotton and paper, the action being allowed to proceed sufficiently to attack the constituent fibres and convert them into colloidal cupro-ammonium compounds, which are then dried, producing a characteristic green-coloured finish of colloidal cellulose and rendering the goods impervious to water. The important industry of mercerization has been mentioned above; this is carried out on both yarns and cloth of cotton goods chiefly composed of Egyptian cottons. A high lustrous finish is produced, giving the goods very much the appearance of silk.
Of special importance are the more recent developments in the production of artificial fibres of all dimensions, by spinning or drawing the solutions of cellulose or derivatives. Three such processes are in course of evolution, (1) The first is based on the nitrates of cellulose which are dissolved in ether-alcohol, and spun through fine glass jets into air or water, the unit threads being afterwards twisted together to constitute the thread used for weaving (process of Chardonnet and Lehner). These processes were developed in the period 1883 to 1897, at which later date they had assumed serious industrial proportions. (2) The cupro-ammonium solution of cellulose is similarly employed, the solution being spun or drawn into a strong acid bath which instantly regenerates cellulose hydrate in continuous length. (3) Still more recently the “viscose” solution of cellulose,i.e.of the cellulose xanthogenic acid, has been perfected for the production of artificial silk or lustra-cellulose; the alkaline solution of the cellulose derivative being drawn either into concentrated ammonium salt solutions or into acid baths. This product, known as artificial silk, prepared by the three competing processes, was in 1908 an established textile with a total production in Europe of about 5000 tons a year, a quantity which bids fair to be very largely increased by the advent of the viscose process, which will effect a very considerable lowering in the cost of production. The viscose solution of cellulose is also used for a number of industrial effects in connexion with paper-sizing, paper-coating, textile finishes, and the production of book cloth and leather cloth, and, solidified in solid masses, is used in preparing structural solids which can be moulded, turned and fashioned.