beginning of barley harvest is however generally associated with it, while the wheat harvest is connected with Pentecost. The "sheaf of the first-fruits of your harvest," mentioned in Lev. xxiii. 10, is associated in Jewish tradition with the barley harvest (Mishna, Menachoth x.). This, however, is not immediately connected with the Passover, and is of more significance as determining the exact date of Pentecost.

Considering however the two sections of the Passover separately, it is remarkable how many of the ceremonies associated either historically or ceremonially with the Passover have connexion with the idea of a covenant. The folk-etymology of the word Passover given in Exod. xii. 23 seems to connect the original of the feast with a threshold covenant (see Trumbull, Threshold Covenant, Philadelphia, 1902); the daubing of the sideposts and lintel with blood at the original Passover, which finds its counterpart in Babylonian custom (Zimmern, Beit. z. Bab. Rel. ii. 126-7) and in Arabic usage (Wákidí, ed. Kremer, p. 28), implies a blood covenant. The communion meal would, according to the views of Robertson Smith, also involve the idea of a covenant; while the fact that no person joining in the meal should be uncircumcised connects the feast with the covenant of Abraham. Finally, the association of the first-born with the festival specially referred to in the texts, and carried out both in Samaritan tradition, which marks the forehead of the first-born with the blood of the lamb, and in Jewish custom, which obliged the first-born to fast on the day preceding Passover, also connects the idea of the feast with the sacro-sanctity of the first-born. The Hebrew tradition further connects the revelation of the sacred name of the God of the Hebrews with this festival, which thus combines, in itself, all the associations connecting the Hebrews with their God. It is not surprising therefore that Hebrew tradition connects it with the Exodus, the beginning of the theocratic life of the nation. It seems easiest to assume that the festival, so far as the Passover itself is concerned, was actually connected historically with the Exodus.

With regard to the abstention from leavened bread, the inquiry is somewhat more complicated. As before remarked, there seems no direct connexion between the paschal sacrifice and what appears to be essentially an agricultural festival; the Hebrew tradition, to some extent, dissociates them by making the sacrifice on the 14th of Nisan and beginning the Feast of Unleavened Bread on the 15th. This seeming casual connexion, to some extent, confirms the historic connexion suggested by the text, that the Jews at the Exodus had to use bread prepared in haste; but not even Hebrew tradition attempts to explain why the abstention should last for seven days. The attempt of modern critics to account for the period as that in which the barley harvest was gathered in, during which the workers in the field could not prepare leavened bread, is not satisfactory. The first-fruits of the barley harvest are to be gathered on the "morrow of the sabbath" (Lev. xxiii. 11). This expression has formed the subject of dispute between Samaritans and other sectaries and the Jews, the former of whom regard it as referring to the first Sunday during the festival, the latter as a special expression for the second day of the festival itself (see Hoffmann, Lev. ii. 159-215). But whichever interpretation is taken, the connexion of the festival with the harvest is only secondary.

The suggestion has been made by Wellhausen and Robertson Smith that the Passover was, in its original form, connected with the sacrifice of the firstlings, and the latter points to the Arabic annual sacrifices called 'Atair, which some of the lexicographers interpret as firstlings. These were presented in the month Rajab, corresponding to Nisan (Smith, Religion of Semites, p. 210). But the real Arabic sacrifice of firstlings was called Fara'; it might be sacrificed at any time, as was also the case with the Hebrews (Exod. xxii. 30). The paschal lamb was not necessarily a firstling, but only in the first year of its life (Exod. xii. 5). The suggestion of Wellhausen and Robertson Smith confuses the offering of firstlings (Arabic Fara') and that of the first yeanlings of the year in the spring (Arabic 'Atair). It is possible that the Passover was originally connected with the latter (cf. Wellhausen, Reste arab. Heidentums, pp. 94 seq.). As regards

the Feast of Unleavened Bread, now indissolubly connected with the paschal sacrifice, no satisfactory explanation has been given either of its original intention or of its connexion with the Passover. It has been suggested that it was originally a hag or pilgrimage feast to Jerusalem, of which there were three in the year connected with the agricultural festivals (Exod. xxxiv. 17, 18). But the real agricultural occasion was not the eating of unleavened bread but the offering of the first sheaf of the barley harvest on the "morrow of the sabbath" in the Passover week (Lev. xxiii. 10, 11), and this occasion determined the second agricultural festival, the Feast of Weeks, fifty days later (Deut. xvi. 9; Lev. xxiii. 16; see PENTECOST). The suggestion that the eating of cakes of unleavened bread, similar to the Australian "damper," was due to the exigencies of the harvest does not meet the case, since it does not explain the seven days and is incongruous with the fact that the first sheaf of the harvest was put to the sickle not earlier than the third day of the feast. It still remains possible therefore that the seven days' eating of unleavened bread (and bitter herbs) is an historical reminiscence of the incidents of the Exodus, where the normal commissariat did not begin until a week after the first exit. On the other hand, the absence of leaven may recall primitive practice before its introduction as a domestic luxury; sacral rites generally keep alive primitive custom. There was also associated in the Hebrew mind a connexion of impurity and corruption with the notion of leaven which was tabu in all sacrifice (Exod. xxiii. 18; Lev. ii. 11).

According to Robertson Smith, the development of the various institutions connected with the Passover was as follows. In Egypt the Israelites, as a pastoral people, sacrificed the firstlings of their flocks in the spring, and, according to tradition, it was a refusal to permit a general gathering for this purpose that caused the Exodus. When the Israelites settled in Canaan they found there an agricultural festival connected with the beginnings of the barley harvest, which coincided in point of date with the Passover and was accordingly associated with it. At the time of the reformation under Josiah, represented by Deuteronomy, the attempt was made to turn the family thank offering of firstlings into a sacrificial rite performed by the priests in the Temple with the aid of the males of each household, who had to come up to Jerusalem but left the next morning to celebrate the Feast of Unleavened Bread in their homes. During the exile this was found impossible, and the old home ceremonial was revived and was kept up even after the return of the exile. This is a highly ingenious hypothesis to explain the discrepancies of the text, but is, after all, nothing but hypothesis.

There appears to have been originally considerable variety in the mode of keeping the Passover, but the earliest mention in the historical narratives (Josh. v. 11) connects the paschal sacrifice with the eating of unleavened bread. But it is unsafe to assume, from 2 Kings xxiii. 22, that the festival was not kept in the time of the early kings, since Solomon appears to have kept up the three great pilgrimage festivals, 2 Kings ix. 25, and it is possibly referred to in Isa. i. 9. The complex of observances connected with the Passover and the very want of systemization observed in the literary sources would seem to vindicate the primitive character of the feast, which indeed is recognized by all inquirers.

At any rate the Samaritans have, throughout their history, observed the Passover with all its Pentateuchal ceremonial and still observe it down to the present day. They sacrifice the paschal lamb, which is probably the oldest religious rite that has been continuously kept up. In two important points they differ from later Jewish interpretation. The term "between the evenings" (Lev. xxiii. 5) they take as the time between sunset and dark, and the "morrow of the sabbath" (v. 11) they take literally as the first Sunday in the Passover week; wherein they agree with the Sadducees, Boethusians, Karaites and other Jewish sectaries. This would seem to point to a time when the fixing of the sabbath was determined by the age of the moon, so that the first day of the Passover, which is on the 15th of Nisan, would always occur on a sabbath.

It is stated in the gospels that the Last Supper was the Passover meal, though certain discrepancies between the accounts given in the Synoptics and in John render this doubtful. It is, at any rate, certain that Jesus came up to Jerusalem in order to join in the celebration of the Passover. When the Passover fell upon the sabbath, as occurred during his visit, a difficulty arose about the paschal sacrifice, which might involve work on the sabbath. There appears to have been a difference of practice between the Sadducees and the Pharisees on such occasions, the former keeping to the strict rules of the Law and sacrificing on the Friday, whereas the Pharisees did so on the Thursday. It has been suggested that Jesus followed the pharisaic practice, and ate the Passover meal (the Last Supper) on Thursday evening, which would account for the discrepancies in the gospel narratives (see Chwolson, Das letzte Passahmal Jesu, 2nd ed., St Petersburg, 1904). It seems probable in any case that the ritual of the Mass has grown out of that of the Passover service (see Bickell, Messe und Pascha, tr. W. F. Skene, Edinburgh, 1891). Up to the Nicene Council the Church kept Easter (q.v.) coincident with the Jewish Passover, but after that period took elaborate precautions to dissociate the two.

See the commentaries on Exodus and Leviticus; that of Kalisch on the latter book (vol. ii., London, 1871) anticipates much of the critical position. The article in Winer's Bibl. Realwörterbuch gives a succinct account of the older views. A not altogether unsuccessful attempt to defend the Jewish orthodox position is made by Hoffmann in his Commentary on Leviticus (Berlin, 1906, ii. 116-224). Wellhausen's views are given in his Prolegomena, ch. iii. A critical yet conservative view of the whole question is given by R. Schaefer, Das Passah-Mazzoth-Fest (Gutersloh, 1900) which has been partly followed above. For the general attitude towards the comparative claims of institutional archaeology and literary criticism adopted above see J. Jacobs, Studies in Biblical Archaeology (London, 1895). UJ. JA.)

PASSOW, FRANZ LUDWIG CARL FRIEDRICH (1786-1833), German classical scholar and lexicographer, was born at Ludwigslust in Mecklenburg-Schwerin on the 20th of September 1786. In 1807 he was appointed to the professorship of Greek literature at the Weimar gymnasium by Goethe, whose acquaintance he had made during a holiday tour. In 1815 he became professor of ancient literature in the university of Breslau, where he continued to reside until his death on the 11th of March 1833. His advocacy of gymnastic exercises, in which he himself took part, met with violent opposition and caused a quarrel known as the "Breslauer Turnfehde." Passow's great work was his Handwörterbuch der griechischen Sprache (1819-1824), originally a revision of J. G. Schneider's lexicon, which appeared in the fourth edition (1831) as an independent work, without Schneider's name (new ed. by Crönert, 1901). It formed the basis of Liddell and Scott's lexicon. Other works by him are Grundzüge der griech. und röm. Literatur- und Kunstgeschichte (2nd. ed., 1829) and editions of Persius, Longus, Tacitus Germania, Dionysius Periegetes, and Musaeus. His miscellaneous writings have been collected in his Opuscula academica (1835) and Vermischte Schriften (1843).

See Franz Passow's Leben und Briefe (1839), by L. and A. Wachler, which contains a full bibliography.

PASSPORT, or safe-conduct in time of war, a document granted by a belligerent power to protect persons and property from the operation of hostilities. In the case of the ship of a

of the neutral state to suffer the vessel to pass freely with the crew, cargo, passengers, &c., without molestation by the belligerents. The requisition, when issued by the civil authori ties of the port from which the vessel is fitted out, is called a sea-letter. But the terms passport and sea-letter are often used indiscriminately. A form of sea-letter (literae salvi conductus) is appended to the Treaty of the Pyrenees, 1659. The passport is frequently mentioned in treaties, e.g. the Treaty of Copenhagen, 1670, between Great Britain and Denmark. The violation of a passport, or safe conduct, is a grave breach of international law. The offence in the United States is punishable by fine and imprisonment where the passport or safe conduct is granted under the authority of the United States (Act of Congress, April 30, 1790). In its more familiar sense a passport is a document authorizing a person to pass out of or into a country, or a licence or safe-conduct to the person specified therein and authenticating his right to aid and protection. Although most foreign countries may now be entered without passports, the English foreign office recommends travellers to furnish themselves with them, as affording a ready means of identification in case of need. They are usually granted by the foreign office of a state, or by its diplomatic agents abroad. The English Foreign Office charges two shillings for a passport, whatever number of persons may be named in it. Passports granted in England are subject to a stamp duty of sixpence. They may be granted to naturalized as well as natural-born British subjects.

See "The Passport System," by N. W. Sibley, in Jour. Comp. Leg. new series, vol. vii. The regulations respecting passports issued by the English Foreign Office as well as the passport requirements of foreign countries will be found in the annual Foreign Office List

PASTE (O. Fr. paste, modern pâte, Late Lat. pasta, whence also in Span., Port. and Ital., from Gr. máørn or warrá, barley porridge, or salted pottage, wáoσev, to sprinkle with salt), a mixture or composition of a soft plastic consistency. The term is applied to substances used for various purposes, as e.g. in cookery, a mixture of flour and water with lard, butter or suet, for making pies and pastry, or of flour and water boiled, to which starch or other ingredients to prevent souring are added, forming an adhesive for the affixing of wall-paper, bill-posting and other purposes. In technical language, the term is also applied to the prepared clay which forms the body in the manufacture of pottery and porcelain (see CERAMICS) and to the specially prepared glass, known also as strass," from which imitation gems are manufactured. This latter must be the purest, most transparent and most highly refractive glass that can be prepared. These qualities are comprised in the highest degree in a flint glass of unusual density from the large percentage of lead it contains. Among various mixtures regarded as suitable for strass the following is an example: powdered quartz 300 parts, red lead 470, potash (purified by alcohol) 163, borax 22, and white arsenic 1 part by weight. Special precautions are taken in the melting. The finished colourless glass is used for imitation diamonds; and when employed to imitate coloured precious stones the strass is melted up with various metallic oxides. Imitation gems are easily distinguished from real stones by their inferior hardness and by chemical tests; they may generally be detected by the comparatively warm sensation they communicate to the tongue.

PASTEL, the name of a particular method of painting with dry pigments, so called from the "paste" into which they are first compounded. The invention of pastel, which used to be generally called "crayon," has frequently been accredited to Johann Alexander Thiele (1685-1752), landscape-painter and etcher of distinction, as well as to Mme Vernerin and Me Heid (1688-1753), both of Danzig. But the claim cannot be substantiated, as drawing in coloured chalks had been practised long before, e.g. by Guido Reni (1575-1642), by whom a head and bust in this manner exists in the Dresden Galery. Thiele was perhaps the first to carry the art to perfection, it least in Germany, where it was extensively exploited in the

17th century; but his contemporary, Rosalba Carriera of Venice (1675-1757), is more completely identified with it, and in her practice of it made a European reputation which to this day is in some measure maintained. The Dresden Museum contains 157 examples of her work in this medium, portraits, subjects and the like. Thiele was followed by Anton Raphael Mengs (1728-1779) and his sister Theresia Mengs (afterwards Maron, 1725-1806), and by Johann Heinrich Schmidt (1749-1829).

When in 1720 Rosalba Carriera accepted an invitation to visit Paris, where she was received with general enthusiasm, she found the art of pastel-painting well established; that is to say, it was used to reproduce local colour with truth. She made it fashionable and combined truth with nature. Nearly a hundred years before Claude Lorrain had used coloured chalks as Dutch and Italian painters had used them, often with high finish, employing mainly red, blue and black, for the sake of prettiness of effect and not with the intention of reproducing with accuracy the actual colours of the head, the figure, or the landscape before them. This method of making drawings-rehaussés, as they were called-has remained in common use almost to the present day, especially for studies. It is necessary only to cite among many examples the series of heads by Holbein, the highly esteemed studies by Watteau, Boucher and Greuze, and of John Raphael Smith and Sir Thomas Lawrence, to indicate how general has been the employment of the coloured chalk. In 1747 Nattier (1685-1766) showed a pastel portrait of M. Logerot in the Paris Salon, and his son-in-law, Louis Tocqué (16961772), soon followed with similar work. Hubert Drouais (1699-1767) had preceded his rival Nattier in the Salon by a single year with five pastel portraits, and Chardin (1699-1779) followed in 1771. This great master set himself to work in emulation of Quentin de la Tour (1704-1788), who in spite of the ability of his rivals may be regarded as the most eminent pastellist France has produced. His portraits of Mme Boucher and himself appeared in the Salon in 1737; his full strength as a portraitpastellist is to be gauged in the collection of eighty-five of his principal works now in the museum of St Quentin. Then followed Simon Mathurin Lantara (1729-1778), who was one of the first to paint pastel-pictures of landscapes, including sunsets and moonlights, as well as marines, into which the figures were drawn by Joseph Vernet, Casanova and others, and Jean Baptiste Perronneau (1731-1796), the best of whose heads have been often attributed to de la Tour and whose "Jeune fille au chat" in the Louvre, though not the finest, is perhaps the best known of his works, was the last pre-eminent French pastellist of the 18th century. Since then they have been legion; of these it is needful to mention only Girodet and the flower-painters, Jean Saint-Simon and Sprendonck.

Two Swiss painters had considerable influence in spreading the use of pastel-the experimentalist Dietrich Meyer (15721658), one of the first to make designs in coloured chalks (and reputed inventor of soft-ground etching), and Jean Étienne Liotard (1702 or 1704-1788), one of the most brilliant pastellists who ever lived. Two of his works are world-famous, "La Belle Chocolatière de Vienne," executed in 1745, now in the Dresden Muscum, and "La Belle Liseuse" of the following year at the museum at Amsterdam. The latter is a portrait of his niece, Mlle Lavergne. In 1753, and again in 1772, Liotard visited England, where his brilliant work, portraits and landscapes, produced a great effect, almost equal to that of de la Tour twenty years before. To the Royal Academy between 1773 and 1775 Liotard contributed the portraits of Dr Thomson, himself, Lord Duncannon and General Cholmondely.

Crayon-painting was practised in England at an early date, and John Riley (1646-1691), many of whose finest works are attributed to Sir Peter Lely, produced numerous portraits in that medium. Francis Knapton (1698-1778), court painter, was a more prolific master, and he, with William Hoare of Bath (? 1707-1792) who had studied pastel in Italy and made many classic designs in that medium, exhibiting at the Royal Academy | his "Boy as Cupid," "Prudence instructing her Pupil," "Diana,' ," "A Zingara," and others, prepared the way for the

triumph of Francis Cotes (1725-1770). Then for the first time pastel-painting was fully developed by an English hand. Before he became a painter in oil Cotes had worked under Rosalba Carriera, and, although he was rather cold and chalky in his tones, he produced portraits, such as his "Mr and Mrs Joah Bates" and "Lord Hawke," which testify to his high ability. He was, however, far surpassed by his pupil, John Russell, R.A. (1745-1806), who brought the art to perfection, displaying grace and good expression in all his pastel work, whether portrait, fancy picture, historical subject, group, or "conversation-piece." He had brought from Rosalba her four fine pictures representing "The Seasons," and in a great measure founded his style on them. He was strong and brilliant in colour, and when he was at his best his high, smooth finish in no way robbed his work of vigour. Romney (1734-1802) in his single pastel portrait, a likeness of William Cowper the poet, showed that he might have excelled in this medium, which, indeed, was particularly suited to his tender manner. Hugh D. Hamilton (c. 1734-1806) of the Royal Hibernian Academy, produced noteworthy portraits, mainly in grey, red and black, until on the suggestion of Flaxman he abandoned pastel for oil. Ozias Humphry, A.R.A. (1742-1810), painter and miniaturist, is an important figure among the pastellists, commonly believed to be the first in England who made a point of letting his colour strokes be seen (as by Emile Wauters and others in our own day), contrary to the practice of Russell and his predecessors, whose prime effort was to blend all into imperceptible gradations. Richard Cosway, R.A. (1742-1821) was mainly experimental in his pastels, but his portraits, such as that of George prince of Wales, are forcible and brilliant; those of his wife Maria Cosway (17591838) are more delicate. Daniel Gardner (? 1750-1805), whose pictures in oil have often been mitsaken for Reynolds's and Gainsborough's, gave rein to his exuberant fancy and his rather exaggerated taste in compositions which, in his arrangement of children, remind us of Sir Thomas Lawrence in his more fantastic mood. Gardner marked the deterioration of the art, which thereafter declined, Henry Bright (1814-1873) being almost the only pastellist of real power who followed him. Bright's landscapes have probably in their own line never been surpassed. Since 1870 there has been a revival of the art of pastel, the result of a better understanding and appreciation on the part of the public. Grimm's denunciation of it to Diderot-" every one is agreed that pastel is unworthy the notice of a great painter "-which for many years had found general acceptance, is now seen to have been based on forgetfulness or ignorance of the virtues inherent in the method. It was thought that "coloured chalks," as it used to be called in English-speaking countries, promised nothing but sketches of an ephemeral kind, so fragile that they were at the mercy of every chance blow or every touch of dampness. The fact is, that with care no greater than is accorded to every work of art, pastel properly used is not more perishable than the oil-painting or the water-colour. Damp will affect it seriously, but so also will it ruin the watercolour; and rough usage is to be feared for the oil-picture not less than for the pastel. Moreover, pastel possesses advantages that can be claimed by neither oil-painting nor water-colour. That is to say, if pictures in these three mediums be hung side by side for a hundred years in a fair light and in a dry place, the oil-painting will have darkened and very probably have cracked; the water-colour will have faded; but the pastel will remain as bright, fresh, and pure as the day it was painted. If Time and Varnish, which Hogarth and Millais both declared the two greatest of the old masters, will do nothing to "improve" a pastel, neither will they ruin it-time passes it by and varnish must on no account be allowed to approach it. The pastelpainter, therefore, having no adventitious assistance to hope for, or to fear, must secure at once the utmost of which his method is capable.

The advantages of pastel are threefold: those of working, those of results, and those of permanence. The artist has at his command, without necessity of mixing his colours, every hue to be found in nature, so that freshness and luminosity can

toothed cloth. The French paper known as gras gris bleuté is employed by certain of the leading pastellists. The crisp touches of the pastel can be placed side by side, or the "vibrations" which the artist seeks may be obtained by glazes and superposed tones. It should here be mentioned that about the year 1900 M. Jean-François Raffaelli produced in Paris sticks of oil colours which he claimed would in a great measure replace painting with the brush. Although the system was widely tried and many good pictures painted in this method, it was found that the colours became dull, and such vogue as these "solid paints" enjoyed for a time has to a very great exten! disappeared.

The inherent qualities of pastel are those of charm, of subtlety, softness, exquisite depths of tone, unsurpassable harmonies and unique freshness of colour, sweetness, delicacy, mysteryall the virtues sought for by the artist of daintiness and refinement. Pastel-painting is essentially, therefore, the art of the colourist. Now, these very qualities suggest its limitations. Although it is unfair to relegate it-as fashion has foolishly done for so long-to the bunch of pretty triflings which Carlyle called "Pompadourisms," we must recognize that a medium which suggests the bloom upon the peach is not proper to be employed for rendering "grand," or even genre subjects, or for the covering of large surfaces of canvas. It is inappropriate to the painting of classic compositions, although in point of fact it has been so used, not without success. It is best adapted to the rendering of still life, of landscape and of portraiture. But in these cases it is not advisable to aim at that solidity which is the virtue of oil-painting, if only because oil can bring about a better result. The real reason is that, in securing solidity, pastel tends to forfeit that lightness and grace which constitute its special charm and merit. Strength belongs to oil, tenderness and subtlety to pastel, together with freshness and elegance.

The pre-eminent technical advantage, in addition to those already mentioned, is the permanence of the tones. In watercolours there is an admixture of gum and glycerine which may attract moisture from the air; and, besides, the pigment is used in very thin washes. In oil-painting not only does the oil darken with age but sometimes draws oxygen from a pigment and changes its hue. In pastel the colour is put on without any moist admixture, and can be laid on thick. Moreover, the permanence may arise from the method of manufacture. In a very rare work, The Excellency of the Pen and Pencil (1668), a chapter on "how to make pastils" [sic] "of several colours, for drawing figure, landskip, architecture, &c., on blew paper," describes the manner of grinding up the pigments with grease. This used to be the secret of pastel-that every grain of colour was separately and securely locked up in grease, and so was secured from any chemical change that might have come about through contact of the colours with one another or with the atmosphere. With pastel nothing of the kind could occur; and the works of Rosalba Carriera in Italy, of Quentin Latour, Peronneau, Watteau, St Jean, Paul Hoin and Chardin in France, and of Russell and Cotes in England-to name no others -testify to the permanency of the colours. Some manufacturers nowadays employ gum as the binding medium; others beeswax (which at one time was more frequently used than it is at present); others, again, a very small proportion of tallow, and sometimes a little soap. But this introduction of binding media is now adopted only in the case of certain colours. Whether the point or edge of the stick be used (as in pastel drawing), or the side of it, helped with the tips of the fingers (as in pastel painting), the result is equally permanent; and if, when the work is done, it be struck two or three times, and then touched up by hand-crayons, no dropping of colour from the paper need ever occur. The drawing is made on a grained

The art of pastel, as M. Roger Ballu expressed it," was slumbering a little," until in 1870 the Société des Pastellistes was founded in France and met with ready appreciation. With many artists it was a matter of coloured chalks," as, for example, with Millet, Lhermitte and Degas in France, and with Whistler in England. With the majority the full possibilities were seized, and a great number of artists abroad then practised the art for the sake of colour, among Machard, Pointelin, Georges Picard, de Nittis, Iwill, René Billotte whom may be mentioned Adrien Moreau, A. Besnard, Émile Lévy, Jozan, Nozel, Raffaelli, Brochard (mainly upon vellum) and Lévy-Dhurmer in France; in Belgium, Émile Wauters (who has produced a great series of life-sized portraits of both men and women of amazing strength, vitality and completeness) and Fernand in Holland, Josselin de Jong; in Germany, F. von Lenbach, Max Khnopff; in Italy, C. Laurenti, P.Fragiacomo and Giovanni Segantini; Liebermann and Franz Stück; and in Norway, Fritz Thaulow. In England the revival of pastel dates from 1880, when the first exhibition of the Pastel Society was held in the Grosvenor Gallery. The exhibition was a succès d'estime, but after a while the society languished until, in 1899, it was reconstituted, and obtained the adhesion of many of the most distinguished artists practising in the country, as well as of a score of eminent foreign painters." In that year, and since, it has held exhibitions of a high order; and the most noteworthy contributors. Among these are E. A. Abbey, intelligent public appreciation has been directed to the work of R.A.; M'Lure Hamilton, J. M. Swan, R.A.; J. Lorimer, RSA; A. Peppercorn, R. Anning Bell, J. J. Shannon, R.A.; Sir James Guthrie, P.R.S.A.; H. Brabazon, Walter Crane, Melton Fisher, Edward Stott, A.R.A.; S. J. Solomon, R.A.; and W. Rothenstein. See Karl Robert [Georges Meusnier], Le Pastel (Laurens, Paris, 1890); J. L. Sprinck, A Guide to Pastel Painting (Rowney, London': Henry Murray, The Art of Painting and Drawing in Coloured Crayons Winsor & Newton, London). Among carly works are: fcha Russell, R.A., Elements of Painting with Crayons (1776); M.P.R. de C.C., Traité de la peinture au pastel avec les moyens de préven l'altération des couleurs (Paris, 1788); Rosalba Carriera," Diaris degli anni 1720 e 1721 scritto di propria mano in Parigia, &r. (Giovanni Vianelli, Venice, 1793, 4to); Girolamo Zanetti, Elogio di Lapauze, Les Pastels de M. Quentin de La Tour à St Quentin, preface Rosalba Carriera, pittrice (Venice, 1818, 8vo). See also Henri by Gustave Larroumet (Paris); George C. Williamson, Jekn Russel R.A. (London, 1894). (M. H. S.)

PASTEUR, LOUIS (1822-1895), French chemist, was born, on the 27th of December 1822, at Dôle, Franche-Comté, where his father carried on the business of a tanner. Shortly after wards the Pasteur family removed to Arbois, where Louis attended the Ecole primaire, and later the collège of that place. Here he apparently did not especially distinguish himself, belonging to the class of bons ordinaires. Fortunately at Arbois he came under the influence of an excellent teacher in the person of the director of the collège, who must have discerned in the quiet boy the germs of greatness, as he constantly spoke to him of his future career at the Ecole normale in Paris. In October 1838 Louis was sent with a friend to the metropolis, to a school in the Quartier Latin, preparatory to the École normale. But he did not remain long in Paris, for, being a nervous and excitable boy, his health broke down, and he yearned for his home in Franche-Comté. "If only I could smell the tannery once more," said he to his companion, “I should feel well." So home he went, though not for long, as his ambition was still to become a normalien, and to this end he entered the Royal College of Besançon, en attendant l'heureux jour où je serais admis à l'école normale." Step by step he attained his end; in 1840 he won his "bachelier ès lettres," and shortly afterwards he received an appointment as assistant inathematical master in the college. Two years later he passed the examination for the " baccalauréat ès sciences"

enabling him to become candidate for the Ecole normale. But here something (probably the examiner) was at fault, for a note was attached to Pasteur's diploma stating that he was only "mediocre" in chemistry. In those early days and early trials the dominant note of Pasteur's life was sounded. Tc his sisters he writes: "Ces trois choses, la volonté, le travail, le succès, se partagent toute l'existence humaine. La volonté ouvre la porte aux carrieres brillantes et heureuses; le travail les franchit, et une fois arrive au terme du voyage, le succès vient couronner l'œuvre." Throughout his life, and to the very end, "work" was his constant inspiration. On his deathbed he turned to the devoted pupils who watched over their master's last hours. "Où en êtes-vous ?" he exclaimed. Que faitesvous?" and ended by repeating his favourite words, "Il faut travailler."

The first incentive to his serious study of chemistry was given by hearing J. B. A. Dumas lecture at the Sorbonne; and ere long he broke new ground for himself, A. J. Balard having given him an opportunity for chemical work by appointing him to the post of laboratory assistant. A few words of explanation concerning Pasteur's first research are necessary to give the key to all his future work. What was the secret power which enabled him to bring under the domain of scientific laws phenomena of disease which had so far bafiled human endeavour? It simply consisted in the application, to the elucidation of these complex problems, of the exact methods of chemical and physical research. Perhaps the most remarkable discovery of modern chemistry is the existence of compounds, which, whilst possessing an identical composition, are absolutely different bodies, judged of by their properties. The first of the numerous cases of isomerism now known was noted, but unexplained, by J. J. Berzelius. It was that of two tartaric acids, deposited from wine-lees. The different behaviour of these two acids to a ray of polarized light was subsequently observed by J. B. Biot. One possessed the power of turning the plane of the polarized ray to the right; the other possessed no rotary power. Still no explanation of this singular fact was forthcoming, and it was reserved for the young chemist from FrancheComté to solve a problem which had baffled the greatest chemists and physicists of the time. Pasteur proved that the inactivity of the one acid depended upon the fact that it was composed of two isomeric constituents: one the ordinary or dextrorotary acid, and the other a new acid, which possessed an equally powerful left-handed action. The veteran Biot whose acquaintance Pasteur had made, was incredulous. He insisted on the repetition of the experiment in his presence; and when convinced of the truth of the explanation he exclaimed to the discoverer: "Mon cher enfant, j'ai tant aimé les sciences dans ma vie que cela me fait battre le cœur." Thus at one step Pasteur gained a place of honour among the chemists of the day, and was immediately appointed professor of chemistry at the Faculté of Science at Strasburg, where he soon afterwards married Mlle Laurent, who proved herself to be a true and noble helpmeet. Next he sought to prepare the inactive form of the acid by artificial means; and after great and long-continued labour he succeeded, and was led to the commencement of his classical researches on fermentation, by the observation that when the inactive acid was placed in contact with a special form of mould (Penicillium glaucum) the right-handed acid alone was destroyed, the left-handed variety remained unchanged. So well was his position as a leading man of science now established that in 1854 he was appointed professor of chemistry and dean of the Faculté des Sciences at Lille. In his inaugural address he used significant words, the truth of which was soon manifested in his case: "In the field of observation chance only favours those who are prepared." The diseases or sicknesses of beer and wine had from time immemorial baffled all attempts at cure. Pasteur one day visited a brewery containing both sound and unsound beer. He examined the yeasts under the microscope, and at once saw that the globules from the sound beer were nearly spherical, whilst those from the sour beer were elongated; and this led him to a discovery, the consequences of which have revolutionized chemical

as well as biological science, inasmuch as it was the beginning of that wonderful series of experimental researches in which he proved conclusively that the notion of spontaneous generation is a chimera. Up to this time the phenomenon of fermentation was considered strange and obscure. Explanations had indeed been put forward by men as eminent as Berzelius and Liebig, | but they lacked experimental foundation. This was given in the most complete degree by Pasteur. For he proved that the various changes occurring in the several processes of fermentation as, for example, in the vinous, where alcohol is the chief product; in the acetous, where vinegar appears; and in the lactic, where milk turns sour-are invariably due to the presence and growth of minute organisms called ferments. Exclude every trace of these organisms, and no change occurs. Brewers' wort remains unchanged for years, milk keeps permanently sweet, and these and other complex liquids remain unaltered when freely exposed to air from which all these minute organisms are removed. "The chemical act of fermentation," writes Pasteur, "is essentially a correlative phenomenon of a vital act beginning and ending with it."

But we may ask, as Pasteur did, Why does beer or milk become sour on exposure to ordinary air? Are these invisible germs which cause fermentation always present in the atmosphere? or are they not generated from the organic, but the non-organized constituents of the fermentable liquid? In other words, are these organisms not spontaneously generated? The controversy on this question was waged with spirit on both sides; but in the end Pasteur came off victorious, and in a series of the most delicate and most intricate experimental researches he proved that when the atmospheric germs are absolutely excluded no changes take place. In the interior of the grape, in the healthy blood, no such germs exist; crush the grape, wound the flesh, and expose them to the ordinary air, then changes, either fermentative or putrefactive, run their course. But place the crushed fruit or the wounded animal under conditions which preclude the presence or destroy the life of the germ, and again no change takes place; the grape juice remains sweet and the wound clean. The application of these facts to surgical operations, in the able hands of Lord Lister, was productive of the most beneficent results, and has indeed revolutionized surgical practice.

Pasteur was now the acknowledged head of the greatest chemical movement of the time, the recipient of honours both from his own country and abroad, and installed at the Ecole normale in Paris in a dignified and important post. Not, however, was it without grave opposition from powerful friends in the Academy that Pasteur carried on his work. Biot-who loved and admired him as a son-publicly announced that his enterprise was chimerical and the problem insoluble; Dumas evidently thought so too, for he advised Pasteur not to spend more of his time on such a subject. Yet he persevered: "Travailler, travailler toujours" was his motto, and his patience was rewarded by results which have not merely rendered his name immortal, but have benefited humanity in a way and to a degree for which no one could have ventured to hope. To begin with a comparatively small, though not unimportant, matter, Pasteur's discoveries on fermentation inaugurated a new era in the brewing and wine-making industries. Empiricism, hitherto the only guide, if indeed a guide at all, was replaced by exact scientific knowledge; the connexion of each phenomenon with a controllable cause was established, and rule-of-thumb and quackery banished for ever by the free gift to the world of the results of his researches.

But his powers of patient research and of quick and exact observation were about to be put to a severe test. An epidemic of a fatal character had ruined the French silk producers. Dumas, a native of the Alais district, where the disease was rampant, urged Pasteur to undertake its investigation. Up to that time he had never seen a silkworm, and hesitated to attempt so difficult a task; but at the reiterated request of his friend he consented, and in June 1865 went to the south of France for the purpose of studying the disease on the spot. In September of the same year he was able to announce results which pointed to