BOIL

to heat a fliud up to the point at which it is converted into vapour. The conversion of the fluid into gas takes place chiefly at the point of contact with the source of heat, and the bubbles of vapour rising to the surface, and breaking there, produce a lively commotion, attended with a slight noise, which is called ebullition. The escape of the heated fluid in the form of vapour prevents any further rise of temperature in an open ve el, when the boiling point has been reached. The boiling-point of a fluid thus acquires a scientific importance. According to Tyndall, the exact definition of the boiling-point of a liquid is 'that temperature at which the tension of its vapour exactly balances the pre ure of the atmosphere.* Tyndall found the boiling-point of water at the summit of Mount Rosa to be 184*92", of Mount Blanc 184■95^ Spirits boil at the lowest temperature, pure water next, the fixed oils still higher. Water freed of air has its tension so much increased as to resist boiling for 100** Fahr. above the usual boiling-point. The boiling-point of water under the common pre ure is one of tiie fixed poiats in the gradation of the thermometer. In Fahrenheit's thermometer it marks 21 2**, in the CealAfgnde 100", and 80 in Reaumur's. This point is uniform only in case of complete boiling, and under a uniform pre ure of the atmosphere. The influence of this pre ure appears from experiments. In an exhausted receiver the heat of the human hand is sufficient to make water boil; while, on the contrary, in Papin's digester, where the confinement prevents evaporation, it may be heated to 300" or 400" without boiling. Under the common pre ure of the atmosphere, the boiling-point of alcohol is 176"; that of mercury, 662"; that of sulphuric ether, 96"; that of oil of turpentine, 316"; that of sulphuric acid, 620" Fahr. From the experiments of Profe or Robinson, it appears that in a vacuum all liquids boil about 145" lower than in the open air, under a pre ure of 30 inches of mercury; water, therefore, would boil in a vacuum at 67". Ether may be made to boil at the common temperature by merely exhausting the air from the ve el in which it is contained. BOIL. A boil is a small tumour of a conical shape, elevated above the surface of the body. Its base is hard, while its apex is soft, of a whitish colour, and exceedingly painf uL The pain in boik is generally severe and burning, and hence the name. Boils generally occur in persons of unhealthy constitutions, in those of intemperate habits, and they often arise from, or at least follow, disease of the digestive organs. They vary considerably in size. In treating a boil suppuration should be stimulated by poultices and fomentation; afterwards a free cruoal incision should be made into the tumour, and the matter, together with the dead cellular ti ue, or core, as it is called, must be forcibly squeezed out. If the core is adherent it must be destroyed by caustic, as it otherwise tends to keep up irritation. Attention must also be paid to the digestive oigans. If these are much deranged, an emetic should first be given, followed by some gentie purgative. Afterwards Plummer's piUs (calomel, antimony, and guaiacum), followed by small doses of Epsom salts, may be given occasionally. Anodynes are sometimes nece ary when the constitutional irritation is very great. BOILEAU - BESPRfiAUX, Nioholab (commonly called £oileau)t a French poet^ bom in 1636, at Crosne, near Paris; (Hed 1711. He commenced his studies in the Collie d'Haroourt, and continued them in the College de Beauvais. Even in Mb early youth he read with ardour the great poets of antiquity, and tried his own powers in a tragedy, though with littie succe . After having completed his ftc«y^ft^T^Wl studies, he entered upon the career of the law; but soon left it from dinndination, tried some other pursuits, and resolved, finally, to devote himself entirely to belles-lettres. His first satire, Les Adieux k Paris, made known his talents. In 1666 he published seven satires, with an introduction, addre ed to the king. They met with extraordinary applause, for no one before him had written with sud i eleganoe of versification. But in this, and in the purity of bis language, and the deame with which he sets forth his luminous principles, consists their chief merit; profound or original ideas we should look for in vain, though the pieces are not destitute of graceful touches and delicate strokes. They are unequal in merit. The satires Sur I'fiquivoque and Sur THomme have undeniable defects. That on women, which he wrote at a more advanced age, is monotonous, and deficient in humour. His episUes, in which he is the suooe f ul rival of Horace, are more esteemed at the present day. They display a graceful versification, a natural and sustained style, vigorous and weUconnected ideas. These were followed by his Art Po^tique, in which he describes with precision and taste all the different kinds of poetry (with the exception of the apologue), and lays down rules for them. In regularity of plan, happy transitioxui, and continued gance of style, thifl poem is superior to the Ars Poetic a of Horace. It was long regarded, not only France, but also in foreign countries, as a poetical code, and has eveiywhere had a favourable ixifluence, as it inculcates purity and regularity, and subjects the productions of poetical genius to a fixed standard. Boileau-Despr^ux's censures of Ta o and Quinault, with some other equally unfounded opinions, display a narrowne of spirit. He had many opponents, who accused him of want of fertility, invention, variety. To refute them he wrote his Lutrin, a mock heroic poem, which is still unrivalled in the eyes the French. A music-stand, which has been removed from its place, had occasioned di ensions in a chapter: this is the subject of Boileau-Deepr^ux's poem, in which his art of making petty details interesting deserves as much praise as the other excellencies his poetry already enumerated. In his life, Boileau- Desprdaux was amiable and generous. Louis XIV. gave him the place of historiographer, in connection with Racine, with whom he maintained the friendly relations throughout life. They frequently submitted their works to each other for revision. The correspondence of Badne and Boileau-Desprdaux is included in the collected works of both writers. As Boileau-Despr^ux had attacked the academicians in several of his writings, he was not received their society until 1684, and then only by the interference of tiie king. He died of dropsy. M. de Surin has publish^ (Euvres de Boileau, with a menta^, Paris, 1821-3, four vols. An edition edited by St. Prix, also in four vols., has appeared in Paris 1830; another by the same editor, with notes of the commentators, in 1860. 266