1793. He had, however, entered the ranks of the Girondins, and had voted

in the trial of the king against the death penalty and in favour of the appeal to the people. He resigned his seat in the Convention on the 20th of January. After the death of the king his opposition became more marked; he denounced the September massacres, but when called upon to justify his attitude confined himself to attacking Marat, who was at the time all-powerful. His friends tried in vain to obtain his appointment as minister of the marine; and he failed to obtain even a post as officer. He was arrested on the 23rd of September at Ville d'Avray, near Paris, and taken before the Revolutionary Tribunal, where he was accused of having conspired for the restoration of the monarchy, and of having insulted national representation by resigning his position in the legislature. He was executed on the 4th of December 1793. His brother, GUY PIERRE (1747-1822), also served in the navy, and took part in the American war of independence. He did not accept the principles of the Revolution, but emigrated. He was restored to his rank in the navy in 1803, and died in 1822, after having been _préfet maritime_ of Antwerp, and prefect of the department of Meurthe. See Kersaint's own works, _Le Bon Sens_ (1789); the _Rubicon_ (1789); _Considérations sur la force publique et l'institution des gardes nationales_ (1789); _Lettre à Mirabeau_ (1791); _Moyens présentés à l'Assemblée nationale pour rétablir la paix et l'ordre dans les colonies_; also E. Chevalier, _Histoire de la Marine française sous la première République_; E. Charavay, _L'Assemblée électorale de Paris en 1790 et 1791_ (Paris, 1890); and Agénor Bardoux, _La Duchesse de Duras_ (Paris, 1898), the beginning of which deals with Kersaint, whose daughter married Amédée de Duras. (R. A.*) KERVYN DE LETTENHOVE, CONSTANTINE BRUNO, BARON, (1817-1891), Belgian historian, was born at Saint-Michel-les-Bruges in 1817. He was a member of the Catholic Constitutional party and sat in the Chamber as member for Eecloo. In 1870 he was appointed a member of the cabinet of Anethan as minister of the interior. But his official career was short. The cabinet appointed as governor of Lille one Decker, who had been entangled in the financial speculations of Langand-Dumonceau by which the whole clerical party had been discredited, and which provoked riots. The cabinet was forced to resign, and Kervyn de Lettenhove devoted himself entirely to literature and history. He had already become known as the author of a book on Froissart (Brussels, 1855), which was crowned by the French Academy. He edited a series of chronicles--_Chroniques relatives à l'histoire de la Belgique sous la domination des ducs de Bourgogne_ (Brussels, 1870-1873), and _Rélations politiques des Pays Bas et de l'Angleterre sous le regne de Philippe II._ (Brussels, 1882-1892). He wrote a history of _Les Hugenots et les Gueux_ (Bruges, 1883-1885) in the spirit of a violent Roman Catholic partisan, but with much industry and learning. He died at Saint-Michel-les-Bruges in 1891. See _Notices biographiques et bibliographiques de l'académie de Belgique_ for 1887. KESHUB CHUNDER SEN (KESHAVA CHANDRA SENA) (1838-1884), Indian religious reformer, was born of a high-caste family at Calcutta in 1838. He was educated at one of the Calcutta colleges, where he became proficient in English literature and history. For a short time he was a clerk in the Bank of Bengal, but resigned his post to devote himself exclusively to literature and philosophy. At that time Sir William Hamilton, Hugh Blair, Victor Cousin, J. H. Newman and R. W. Emerson were among his favourite authors. Their works made the deepest impression on him, for, as he expressed it, "Philosophy first taught me insight and reflection, and turned my eyes inward from the things of the external world, so that I began to reflect on my position, character and destiny." Like many other educated Hindus, Keshub Chunder Sen had gradually dissociated himself from the popular forms of the native religion, without abandoning what he believed to be its spirit. As early as 1857 he joined the Brahma Samaj, a religious association aiming at the reformation of Hinduism. Keshub Chunder Sen threw himself with enthusiasm into the work of this society and in 1862 himself undertook the ministry of one of its branches. In the same year he helped to found the Albert College and started the _Indian Mirror_, a weekly journal in which social and moral subjects were discussed. In 1863 he wrote _The Brahma Samaj Vindicated_. He also travelled about the country lecturing and preaching. The steady development of his reforming zeal led to a split in the society, which broke into two sections, Chunder Sen putting himself at the head of the reform movement, which took the name "Brahma Samaj of India," and tried to propagate its doctrines by missionary enterprise. Its tenets at this time were the following: (1) The wide universe is the temple of God. (2) Wisdom is the pure land of pilgrimage. (3) Truth is the everlasting scripture. (4) Faith is the root of all religions. (5) Love is the true spiritual culture. (6) The destruction of selfishness is the true asceticism. In 1866 he delivered an address on "Jesus Christ, Europe and Asia," which led to the false impression that he was about to embrace Christianity. This helped to call attention to him in Europe, and in 1870 he paid a visit to England. The Hindu preacher was warmly welcomed by almost all denominations, particularly by the Unitarians, with whose creed the new Brahma Samaj had most in common, and it was the committee of the British and Foreign Unitarian Association that organized the welcome soirée at Hanover Square Rooms on the 12th of April. Ministers of ten different denominations were on the platform, and among those who officially bade him welcome were Lord Lawrence and Dean Stanley. He remained for six months in England, visiting most of the chief towns. His eloquence, delivery and command of the language won universal admiration. His own impression of England was somewhat disappointing. Christianity in England appeared to him too sectarian and narrow, too "muscular and hard," and Christian life in England more materialistic and outward than spiritual and inward. "I came here an Indian, I go back a confirmed Indian; I came here a Theist, I go back a confirmed Theist. I have learnt to love my own country more and more." These words spoken at the farewell soirée may furnish the key to the change in him which so greatly puzzled many of his English friends. He developed a tendency towards mysticism and a greater leaning to the spiritual teaching of the Indian philosophies, as well as a somewhat despotic attitude towards the Samaj. He gave his child daughter in marriage to the raja of Kuch Behar; he revived the performance of mystical plays, and himself took part in one. These changes alienated many followers, who deserted his standard and founded the Sadharana (General) Brahma Samaj (1878). Chunder Sen did what he could to reinvigorate his own section by a new infusion of Christian ideas and phrases, e.g. "the New Dispensation," "the Holy Spirit." He also instituted a sacramental meal of rice and water. Two lectures delivered between 1881 and 1883 throw a good deal of light on his latest doctrines. They were "The Marvellous Mystery, the Trinity," and "Asia's Message to Europe." This latter is an eloquent plea against the Europeanizing of Asia, as well as a protest against Western sectarianism. During the intervals of his last illness he wrote _The New Samhita, or the Sacred Laws of the Aryans of the New Dispensation_. He died in January 1884, leaving many bitter enemies and many warm friends. See the article BRAHMA SAMAJ; also P. Mozoomdar, _Life and Teachings of Keshub Chunder Sen_ (1888). KÉSMÁRK (Ger. Käsmark), a town of Hungary, in the county of Szepes, 240 m. N.E. of Budapest by rail. Pop. (1900), 5560. It is situated on the Poprad, at an altitude of 1950 ft., and is surrounded on all sides by mountains. Among its buildings are the Roman Catholic parish church, a Gothic edifice of the 15th century with fine carved altars; a wooden Protestant church of the 17th century; and an old town-hall. About 12 m. W. of Késmárk lies the famous watering-place Tatrafüred (Ger. Schmecks), at the foot of the Schlagendorfer peak in the Tatra Mountains. Késmárk is one of the oldest and most important Saxon settlements in the north of Hungary, and became a royal free town at the end of the 13th century, In 1440 it became the seat of the counts of Szepes (Ger., _Zips_), and in 1464 it was granted new privileges by King Matthias Corvinus. During the 16th century, together with the other Saxon towns in the Szepes county, it began to lose both its political and commercial importance. It remained a royal free town until 1876. KESTREL (Fr. _Cresserelle_ or _Créçerelle_, O. Fr. _Quercerelle_ and _Quercelle_, in Burgundy _Cristel_), the English name[1] for one of the smaller falcons. This bird, though in the form of its bill and length of its wings one of the true falcons, and by many ornithologists placed among them under its Linnaean name of _Falco tinnunculus_, is by others referred to a distinct genus _Tinnunculus_ as _T. alaudarius_--the last being an epithet wholly inappropriate. We have here a case in which the propriety of the custom which requires the establishment of a genus on structural characters may seem open to question. The differences of structure which separate _Tinnunculus_ from _Falco_ are of the slightest, and, if insisted upon, must lead to including in the former birds which obviously differ from kestrels in all but a few characters arbitrarily chosen; and yet, if structural characters be set aside, the kestrels form an assemblage readily distinguishable by several peculiarities from all other _Falconidae_, and an assemblage separable from the true Falcons of the genus _Falco_, with its subsidiary groups _Aesalon_, _Hypotriorchis_, and the rest (see FALCON). Scarcely any one outside the walls of an ornithological museum or library would doubt for a moment whether any bird shown to him was a kestrel or not; and Gurney has stated his belief (_Ibis_, 1881, p. 277) that the aggregation of species placed by Bowdler Sharpe (_Cat. Birds Brit. Mus._ i. 423-448) under the generic designation of _Cerchneis_ (which should properly be _Tinnunculus_) includes "three natural groups sufficiently distinct to be treated as at least separate subgenera, bearing the name of _Dissodectes_, _Tinnunculus_ and _Erythropus_." Of these the first and last are not kestrels, but are perhaps rather related to the hobbies (_Hypotriorchis_). The ordinary kestrel of Europe, _Falco tinnunculus_ or _Tinnunculus alaudarius_, is by far the commonest bird of prey in the British Islands. It is almost entirely a summer migrant, coming from the south in early spring and departing in autumn, though examples (which are nearly always found to be birds of the year) occasionally occur in winter, some arriving on the eastern coast in autumn. It is most often observed while hanging in the air for a minute or two in the same spot, by means of short and rapid beats of its wings, as, with head pointing to windward and expanded tail, it is looking out for prey--which consists chiefly of mice, but it will at times take a small bird, and the remains of frogs, insects and even earthworms have been found in its crop. It generally breeds in the deserted nest of a crow or pie, but frequently in rocks, ruins, or even in hollow trees--laying four or five eggs, mottled all over with dark brownish-red, sometimes tinged with orange and at other times with purple. Though it may occasionally snatch up a young partridge or pheasant, the kestrel is the most harmless bird of prey, if it be not, from its destruction of mice and cockchafers, a beneficial species. Its range extends over nearly the whole of Europe from 68° N. lat., and the greater part of Asia--though the form which inhabits Japan and is abundant in north-eastern China has been by some writers deemed distinct and called _T. japonicus_--it is also found over a great part of Africa, being, however, unknown beyond Guinea on the west and Mombasa on the east coast (_Ibis_, 1881, p. 457). The southern countries of Europe have also another and smaller species of kestrel, _T. tinnunculoides_ (the _T. cenchris_ and _T. naumanni_ of some writers), which is widely spread in Africa and Asia, though specimens from India and China are distinguished as _T. pekinensis_. Three other species are found in Africa--_T. rupicola_, _T. rupicoloides_ and _T. alopex_--the first a common bird in the Cape, while the others occur in the interior. Some of the islands of the Ethiopian region have peculiar species of kestrel, as the _T. newtoni_ of Madagascar, _T. punctatus_ of Mauritius and _T. gracilis_ of the Seychelles; while, on the opposite side, the kestrel of the Cape Verde Islands has been separated as _T. neglectus_. The _T. sparverius_, commonly known in Canada and the United States as the "sparrow-hawk," is a beautiful little bird. Various attempts have been made to recognize several species, more or less in accordance with locality, but the majority of ornithologists seem unable to accept the distinctions which have been elaborated chiefly by Bowdler Sharpe in his _Catalogue_ and R. Ridgway (_North American Birds_, iii. 150-175), the former of whom recognizes six species, while the latter admits but three--_T. sparverius_, _T. leucophrys_ and _T. sparverioides_--with five geographical races of the first, viz. the typical _T. sparverius_ from the continent of North America except the coast of the Gulf of Mexico; _T. australis_ from the continent of South America except the North Atlantic and Caribbean coasts; _T. isabellinus_, inhabiting continental America from Florida to Fr. Guiana; _T. dominicensis_ from the Lesser Antilles as far northwards as St Thomas; and lastly _T. cinnamominus_ from Chile and western Brazil. _T. leucophrys_ is said to be from Haiti and Cuba; and _T. sparverioides_ peculiar to Cuba only. This last has been generally allowed to be a good species, though Dr Gundlach, the best authority on the birds of that island, in his _Contribucion á la Ornitologia Cubana_ (1876), will not allow its validity. More recently it was found (Ibis, 1881, pp. 547-564) that _T. australis_ and _T. cinnamominus_ cannot be separated, that Ridgway's _T. leucophrys_ should properly be called _T. dominicensis_, and his _T. dominicensis T. antillarum_; while Ridgway has recorded the supposed occurrence of _T. sparverioides_ in Florida. Of other kestrels _T. moluccensis_ is widely spread throughout the islands of the Malay Archipelago, while _T. cenchroides_ seems to inhabit the whole of Australia, and has occurred in Tasmania (_Proc. Roy. Soc. Tasmania_, 1875, pp. 7, 8). No kestrel is found in New Zealand, but an approach to the form is made by the very peculiar _Hieracidea_ (or _Harpe_) _novae-zelandiae_ (of which a second race or species has been described, _H. brunnea_ or _H. ferox_), the "sparrow-hawk," "quail-hawk" and "bush-hawk" of the colonists--a bird of much higher courage than any kestrel, and perhaps exhibiting the more generalized and ancestral type from which both kestrels and falcons may have descended. (A. N.) FOOTNOTE: [1] Other English names are windhover and standgale (the last often corrupted into stonegale and stannell). KESWICK, a market town in the Penrith parliamentary division of Cumberland, England, served by the joint line of the Cockermouth Keswick & Penrith, and London & North-Western railways. Pop. of urban district (1901), 4451. It lies in the northern part of the Lake District, in an open valley on the banks of the river Greta, with the mountain of Skiddaw to the north and the lovely lake of Derwentwater to the south. It is much frequented by visitors as a centre for this famous district--for boating on Derwentwater and for the easy ascent of Skiddaw. Many residences are seen in the neighbourhood, and the town as a whole is modern. Fitz Park, opened in 1887, is a pleasant recreation ground. The town-hall contains a museum of local geology, natural history, &c. In the parish church of Crosthwaite, ¾ m. distant, there is a monument to the poet Southey. His residence, Greta Hall, stands at the end of the main street, close by the river. Keswick is noted for its manufacture of lead pencils; and the plumbago (locally wad) used to be supplied from mines in Borrowdale. Char, caught in the neighbouring lakes, are potted at Keswick in large quantities and exported. KESWICK CONVENTION, an annual summer reunion held at the above town for the main purpose of "promoting practical holiness" by meetings for prayer, discussion and personal intercourse. It has no denominational limits, and is largely supported by the "Evangelical" section of the Church of England. The convention, started in a private manner by Canon Harford-Battersby, then vicar of Keswick, and Mr Robert Wilson in 1874, met first in 1875, and rapidly grew after the first few years, both in numbers and influence, in spite of attacks on the alleged "perfectionism" of some of its leaders and on the novelty of its methods. Its members take a deep interest in foreign missions. In the _History of the C.M.S._, vol. iii. (by Eugene Stock), the missionary influence of the "Keswick men" in Cambridge and elsewhere may be readily traced. See also _The Keswick Convention_: its _Message, its Method and its Men_, edited by C. F. Harford (1906). KET (or KETT), ROBERT (d. 1549), English rebel, is usually called a tanner, but he certainly held the manor of Wymondham in Norfolk. With his brother William he led the men of Wymondham in their quarrel with a certain Flowerden, and having thus come into prominence, he headed the men of Norfolk when they rose in rebellion in 1549 owing to the hardships inflicted by the extensive enclosures of common lands and by the general policy of the protector Somerset. A feast held at Wymondham in July 1549 developed into a riot and gave the signal for the outbreak. Leading his followers to Norwich, Ket formed a camp on Mousehold Heath, where he is said to have commanded 16,000 men, introduced a regular system of discipline, administered justice and blockaded the city. He refused the royal offer of an amnesty on the ground that innocent and just men had no need of pardon, and on the 1st of August 1549 attacked and took possession of Norwich. John Dudley, earl of Warwick, marched against the rebels, and after his offer of pardon had been rejected he forced his way into the city, driving its defenders before him. Then, strengthened by the arrival of some foreign mercenaries, he attacked the main body of the rebels at Dussindale on the 27th of August. Ket's men were easily routed by the trained soldiery, and Robert and William Ket were seized and taken to London, where they were condemned to death for treason. On the 7th of December 1549 Robert was executed at Norwich, and his body was hanged on the top of the castle, while that of William was hanged on the church tower at Wymondham. See F. W. Russell, _Kett's Rebellion_ (1859), and J. A. Froude, _History of England_, vol. iv. (London, 1898). KETCH, JOHN (d. 1686), English executioner, who as "Jack Ketch" gave the nickname for nearly two centuries to his successors, is believed to have been appointed public hangman in the year 1663. The first recorded mention of him is in _The Plotters Ballad, being Jack Ketch's incomparable Receipt for the Cure of Traytorous Recusants and Wholesome Physick for a Popish Contagion_, a broadside published in December 1672. The execution of William, Lord Russell, on the 21st of July 1683 was carried out by him in a clumsy way, and a pamphlet is extant which contains his "Apologie," in which he alleges that the prisoner did not "dispose himself as was most suitable" and that he was interrupted while taking aim. On the scaffold, on the 15th of July 1685, the duke of Monmouth, addressing Ketch, referred to his treatment of Lord Russell, the result being that Ketch was quite unmanned and had to deal at least five strokes with his axe, and finally use a knife, to sever Monmouth's head from his shoulders. In 1686 Ketch was deposed and imprisoned at Bridewell, but when his successor, Pascha Rose, a butcher, was, after four months in the office, hanged at Tyburn, Ketch was reappointed. He died towards the close of 1686. KETCHUP, also written _catsup_ and _katchup_ (said to be from the Chinese _kôe-chiap_ or _kê-tsiap_, brine of pickled fish), a sauce or relish prepared principally from the juice of mushrooms and of many other species of edible fungi, salted for preservation and variously spiced. The juices of various fruits, such as cucumbers, tomatoes, and especially green walnuts, are used as a basis of ketchup, and shell-fish ketchup, from oysters, mussels and cockles, is also made; but in general the term is restricted to sauces having the juice of edible fungi as their basis. KETENES, in chemistry, a group of organic compounds which may be considered as internal anhydrides of acetic acid and its substitution derivatives. Two classes may be distinguished: the aldo-ketenes, including ketene itself, together with its mono-alkyl derivatives and carbon suboxide, and the keto-ketenes which comprise the dialkyl ketenes. The aldo-ketenes are colourless compounds which are not capable of autoxidation, are polymerized by pyridine or quinoline, and are inert towards compounds containing the groupings C:N and C:O. The keto-ketenes are coloured compounds, which undergo autoxidation readily, form ketene bases on the addition of pyridine and quinoline, and yield addition compounds with substances containing the C:N and C:O groupings. The ketenes are usually obtained by the action of zinc on ethereal or ethyl acetate solutions of halogen substituted acid chlorides or bromides. They are characterized by their additive reactions: combining with water to form acids, with alcohols to form esters, and with primary amines to form amides. _Ketene_, CH2:CO, was discovered by N. T. M. Wilsmore (_Jour. Chem. Soc._, 1907, vol. 91, p. 1938) among the gaseous products formed when a platinum wire is electrically heated under the surface of acetic anhydride. It is also obtained by the action of zinc on bromacetyl bromide (H. Staudinger, _Ber._ 1908, 41, p. 594). At ordinary temperatures it is a gas, but it may be condensed to a liquid and finally solidified, the solid melting at -151° C. It is characterized by its penetrating smell. On standing for some time a brown-coloured liquid is obtained, from which a colourless liquid boiling at 126-127° C., has been isolated (Wilsmore, ibid., 1908, 93, p. 946). Although originally described as acetylketen, it has proved to be a cyclic compound (Ber., 1909, 42, p. 4908). It is soluble in water, the solution showing an acid reaction, owing to the formation of aceto-acetic acid, and with alkalis it yields acetates. It differs from the simple ketenes in that it is apparently unacted upon by phenols and alcohols. _Dimethyl ketene_, (CH3)2C:CO1 obtained by the action of zinc on [alpha]-brom-isobutyryl bromide, is a yellowish coloured liquid. At ordinary temperatures it rapidly polymerizes (probably to a tetramethylcylobutanedione). It boils at 34° C (750 mm.) (Staudinger, Ber. 1905, 38, p. 1735; 1908, 41, p. 2208). Oxygen rapidly converts it into a white explosive solid. _Diethyl ketene_, (C2H5)2C:CO, is formed on heating diethylmalonic anhydride (Staudinger, ibid.). _Diphenyl ketene_, (C6H5)2C:CO, obtained by the action of zinc on diphenyl-chloracetyl chloride, is an orange-red liquid which boils at 146° C. (12 mm.). It does not polymerize. Magnesium phenyl bromide gives triphenyl vinyl alcohol. KETI, a seaport of British India, in Karachi district, Sind, situated on the Hajamro branch of the Indus. Pop. (1901), 2127. It is an important seat of trade, where seaborne goods are transferred to and from river boats. KETONES, in chemistry, organic compounds of the type R·CO·R´, where R, R´ = alkyl or aryl groups. If the groups R and R´ are identical, the ketone is called a _simple_ ketone, if unlike, a _mixed_ ketone. They may be prepared by the oxidation of secondary alcohols; by the addition of the elements of water to hydrocarbons of the acetylene type RC CH; by oxidation of primary alcohols of the type RR´CH·CH2OH:RR´·CH·CH2OH --> R·CO·R´ + H2O + H2CO2; by distillation of the calcium salts of the fatty acids, C_(n)H_(2n)O2; by heating the sodium salts of these acids C_(n)H_(2n)O2 with the corresponding acid anhydride to 190° C. (W. H. Perkin, _Jour. Chem. Soc._, 1886, 49, p. 322); by the action of anhydrous ferric chloride on acid chlorides (J. Hamonet, _Bull. de la soc. chim._, 1888, 50, p. 357), 2C2H5COCl --> C2H5·CO·CH(CH3)·COCl --> C2H5·CO·CH(CH3)·CO2H --> C2H5·CO·CH2·CH3; and by the action of zinc alkyls on acid chlorides (M. Freund, Ann., 1861, 118, p. 1), 2CH3COCl + ZnC(H3)2 = ZnCl2 + 2CH3·CO·CH3. In the last reaction complex addition products are formed, and must be quickly decomposed by water, otherwise tertiary alcohols are produced (A. M. Butlerow, _Jahresb._, 1864, p. 496; _Ann._ 1867, 144, p. 1). They may also be prepared by the decomposition of ketone chlorides with water; by the oxidation of the tertiary hydroxyacids; by the hydrolysis of the ketonic acids or their esters with dilute alkalis or baryta water (see ACETO-ACETIC ESTER); by the hydrolysis of alkyl derivatives of acetone dicarboxylic acid, HO2C·CH2·CO·CHR·CO2H; and by the action of the Grignard reagent on nitriles (E. Blaise, _Comptes rendus_, 1901, 132, p. 38), R·CN + R´M_(g)I --> RR´C:N·M_(g)I --> R·CO·R´ + NH3 + M_(g)I·OH. The ketones are of neutral reaction, the lower members of the series being colourless, volatile, pleasant-smelling liquids. They do not reduce silver solutions, and are not so readily oxidized as the aldehydes. On oxidation, the molecule is split at the carbonyl group and a mixture of acids is obtained. Sodium amalgam reduces them to secondary alcohols; phosphorus pentachloride replaces the carbonyl oxygen by chlorine, forming the ketone chlorides. Only those ketones which contain a methyl group are capable of forming crystalline addition compounds with the alkaline bisulphites (F. Grimm, _Ann._, 1871, 157, p. 262). They combine with hydrocyanic acid to form nitriles, which on hydrolysis furnish hydroxyacids, (CH2)2CO --> (CH3)2C·OH·CN --> (CH3)2·C·OH·CO2H; with phenylhydrazine they yield hydrazones; with hydrazine they yield in addition ketazines RR´·C:N·N:C·RR´ (T. Curtius), and with hydroxylamine ketoximes. The latter readily undergo the "Beckmann" transformation on treatment with acid chlorides, yielding substituted acid amides. RR´·C:NOH --> RC(NR´)·OH --> R·CO·NHR´ (see OXIMES, also A. Hantzsch, Ber., 1891, 24, p. 13). The ketones react with mercaptan to form mercaptols (E. Baumann, _Ber._, 1885, 18, p. 883), and with concentrated nitric acid they yield dinitroparaffins (G. Chancel, _Bull. de la soc. chim._, 1879, 31, p. 503). With nitrous acid (obtained from amyl nitrite and gaseous hydrochloric acid, the ketone being dissolved in acetic acid) they form isonitrosoketones, R·CO·CH:NOH (L. Claisen, _Ber._, 1887, 20, pp. 656, 2194). With ammonia they yield complex condensation products; acetone forming di- and tri-acetonamines (W. Heintz, _Ann._ 1875, 178, p. 305; 1877, 189, p. 214). They also condense with aldehydes, under the influence of alkalis or sodium ethylate (L. Claisen, _Ann._, 1883, 218, pp. 121, 129, 145; 1884, 223, p. 137; S. Kostanecki and G. Rossbach, _Ber._, 1896, 29, pp. 1488, 1495, 1893, &c.). On treatment with the Grignard reagent, in absolute ether solution, they yield addition products which are decomposed by water with production of tertiary alcohols (V. Grignard, _Comptes rendus_, 1900, 130, P. 1322 et seq.), RR´CO --> RR´·C(OM_(g)I)·R´´ --> RR´R´´·C(OH) + M_(g)I·OH. Ketones do not polymerize in the same way as aldehydes, but under the influence of acids and bases yield condensation products; thus acetone gives mesityl oxide, phorone and mesitylene (see below). For _dimethyl ketone_ or acetone, see ACETONE. _Diethyl ketone_, (C2H5)2·CO, is a pleasant-smelling liquid boiling at 102.7° C. With concentrated nitric acid it forms dinitroethane, and it is oxidized by chromic acid to acetic and propionic acids. _Methylnonylketone_, CH3·CO·C9H19, is the chief constituent of oil of rue, which also contains _methylheptylketone_, CH3·CO·C7H15, a liquid of boiling-point 85-90° C. (7 mm.), which yields normal caprylic acid on oxidation with hypobromites. _Mesityl oxide_, (CH3)2C:CH·CO·CH3, is an aromatic smelling liquid of boiling point 129.5-130° C. It is insoluble in water, but readily dissolves in alcohol. On heating with dilute sulphuric acid it yields acetone, but with the concentrated acid it gives mesitylene, C9H12. Potassium permanganate oxidizes it to acetic acid and hydroxyisobutyric acid (A. Pinner, _Ber._, 1882, 15, p. 591). It forms hydroxyhydrocollidine when heated with acetamide and anhydrous zinc chloride (F. Canzoneri and G. Spica, _Gazz. chim. Ital._, 1884, 14, p. 349). _Phorone_, (CH3)2C:CH·CO·CH:C(CH3)2, forms yellow crystals which melt at 28° C. and boil at 197.2° C. When heated with phosphorus pentoxide it yields acetone, water and some pseudo-cumene. Dilute nitric acid oxidizes it to acetic and oxalic acids, while potassium permanganate oxidizes it to acetone, carbon dioxide and oxalic acid. DIKETONES.--The diketones contain two carbonyl groups, and are distinguished as [alpha] or 1.2 diketones, [beta] or 1.3 diketones, [gamma] or 1.4 diketones, &c., according as they contain the groupings -CO·CO-, -CO·CH2·CO-, -CO·CH2·CH2·CO-, &c. The [alpha]-diketones may be prepared by boiling the product of the action of alkaline bisulphites on isonitrosoketones with 15% sulphuric acid (H. v. Pechmann, _Ber._, 1887, 20, p. 3112; 1889, 22, p. 2115), CH3·CO·C:(N·OH)·CH3 --> CH3·CO·C:(NHSO3)·CH3 --> CH3·CO·CO·CH3; or by the action of isoamyl nitrite on the isonitrosoketones (O. Manasse, _Ber._, 1888, 21, p. 2177), C2H5·CO·C = (NOH)·CH3 + 11C5HONO = C2H5·CO·CO·CH3 + C5H11OH + N2O. They condense with orthodiamines to form quinoxalines (O. Hinsberg, _Ann._, 1887, 237, p. 327), and with ammonia and aldehydes to form imidazoles. _Diacetyl_, CH3·CO·CO·CH3, is a yellowish green liquid, which boils at 87-88°C., and possesses a pungent smell. It combines with sodium bisulphite and with hydrocyanic acid. Dilute alkalis convert it into paraxyloquinone. The [beta]-diketones form characteristic copper salts, and in alcoholic solution they combine with semicarbazide to form products which on boiling with ammoniacal silver nitrate solution give pyrazoles (T. Posner, _Ber._, 1901, 34, p. 3975); with hydroxylamine they form isoxazoles, and with phenylhydrazine pyrazoles. _Acetyl acetone_, CH3·CO·CH2·CO·CH3, may be prepared by the action of aluminium chloride on acetyl chloride, or by condensing ethyl acetate with acetone in the presence of sodium (L. Claisen). It is a liquid of boiling point 136° C. It condenses readily with aniline to give [alpha][gamma]-dimethyl quinoline. The [gamma]-diketones are characterized by the readiness with which they yield furfurane, pyrrol and thiophene derivatives, the furfurane derivatives being formed by heating the ketones with a dehydrating agent, the thiophenes by heating with phosphorus pentasulphide, and the pyrrols by the action of alcoholic ammonia or amines. _Acetonyl acetone_, CH3·CO·CH2·CH2·CO·CH3, a liquid boiling at 194° C., may be obtained by condensing sodium aceto-acetate with mono-chloracetone (C. Paal, Ber., 1885, 18, p. 59), CH3COCH2Cl + Na·CH·COCH3(COOR) --> CH3CO·CH2·CH·COCH3(COOR) --> CH3CO·CH2·CH2·COCH3; or by the hydrolysis of diaceto-succinic ester, prepared by the action of iodine on sodium aceto-acetate (L. Knorr, _Ber._, 1889, 22, pp. 169, 2100). 1.5 diketones have been prepared by L. Claisen by condensing ethoxymethylene aceto-acetic esters and similar compounds with [beta]-ketonic esters and with 1.3 diketones. The ethoxymethylene aceto-acetic esters are prepared by condensing aceto-acetic ester with ortho-formic ester in the presence of acetic anhydride (German patents 77354, 79087, 79863). The 1.5 diketones of this type, when heated with aqueous ammonia, form pyridine derivatives. Those in which the keto groups are in combination with phenyl residues give pyridine derivatives on treatment with hydroxylamine, thus benzamarone, C6H5CH[CH(C6H5)·CO·C6H5], gives pentaphenylpyridine, NC5(C6H5)5. On the general reactions of the 1.5 diketones, see E. Knoevenagel (_Ann._, 1894, 281, p. 25 et seq.) and H. Stobbe (_Ber._, 1902, 35, p. 1445). Many cyclic ketones are known, and in most respects they resemble the ordinary aliphatic ketones (see POLYMETHYLENES; TERPENES). KETTELER, WILHELM EMMANUEL, BARON VON (1811-1877), German theologian and politician, was born at Harkotten, in Bavaria, on the 25th of December