Page:The American Cyclopædia (1879) Volume II.djvu/813

 BOILING POINT 793 philosophical, although he continued to use satire as a potential engine of reform. The French academy, though incensed at his bold criticisms, could not exclude him beyond 1684 ; and with Racine he also became one of the earliest members of the academy of medals (afterward of inscriptions). Louis XIV. pre- sented him with a fine residence at Auteuil, where the choicest spirits of France delighted in Boileau's conversation, the sting of his satire being smoothed over by his kindly nature. According to Mine, de Sevigne, he was cruel only in writing. He was tenderly devoted to Moliere, Racine, and Lafontaine, though often unsparing in his criticism of their works, and successfully exerted his influence with Louis XIV. for restoring a pension to the aged Cor- neille. At a later period Mme. de Maintenon took umbrage at his disparaging remarks on Scarron in the presence of Louis XIV. ; and ul- tramontane influence also working against him, he forfeited the favor of the monarch and his court, which he ceased to frequent after the death of Racine (1699), the king having re- ceived him on his announcement of this event with marked coldness. Subsequently he was prohibited from publishing his 12th satire, De ^equivoque. In his disappointment he sold his house at Auteuil and ended his life in Paris in sadness, which was increased by his infirmities. He iirst resided in a cloister of Notre Dame, and finally, according to the latest researches, in the rue de Jerusalem, and not as previously stated in a village near Paris. His greatest work is Uart poetique (1674), a didactic poem, establishing a new system of poetical and dra- matic composition ; and the first four cantos of Le lutrin (1674), a heroico-comicpoem, were ad- mired as gems of fancy and humor. Many of his didactic Epitre* also acquired celebrity, and his other productions include Satires, jUpigrammeg, Dialogua de lapodsie, de la mutique et des heros de roman, and an annotated translation of the treatise on the sublime by Longinus. Guided solely by his judgment and his fine perceptions of the true and the beautiful, he was wrongly represented by those whose pedantry he de- nounced as destitute of all emotional powers. Voltaire characterized him as the legislator of Parnassus, and his reputation as the founder of a new school of criticism and composition has survived all the changes in French literature, as attested by Sainte-Beuve and other recent authorities. Among the best editions of his works are those by Daunou (3 vols., Paris, 1809 ; 4 vols., 1825) ; by Saint-Surin, with copious notes (4 vols., 1824) ; and by Berriat Saint-Prix (4 vols., 1830 ; new ed., 1860, with an essay by Sainte-Beuve). Auguste Laverdet has published a complete edition of Boileau's Correspondance (2 vols., 1856). BOILING POINT, the temperature at which a liquid is converted into vapor with ebullition. It varies with the nature of the liquid and with the degree of pressure upon it, but it is ordi- narily understood to mean that temperature at which the boiling occurs when the surface of the liquid is exposed to an atmospheric pressure equal to maintaining a column of mercury 29-922 inches in height. It is, conse- quently, the point at which the tension of the vapor is equal to the pressure upon the liquid. During the boiling of a liquid in the open air, therefore, the temperature remains constant, even when the amount of heat supplied to the liquid is increased. The additional heat, in- stead of being retained, is expended in con- verting an increased quantity of the liquid into vapor. If pure water is boiled in an open metallic vessel when the barometer stands at 29-922 inches, it will be observed that the ebullition takes place and continues, for along time at least, at 212 F. If we substitute al- cohol for water, ebullition will commence at 173 ; and if sulphuric ether is used, its boiling point will be found at 95, a temperature below that of the human body. There are several bodies which at ordinary temperatures are gases, but which by the abstraction of heat or subjection to pressure, or both, may be reduced to liquids, whose boiling points are therefore below the ordinary temperature of the atmos- phere. The following table gives the boiling points of several of both these classes of bodies, and also the atmospheric pressure at which the observations were made, and the authority : NAME. Boiling point, F. Height of barometer. OBSERVER. 126-22 29-^2 108-76 80-209 ' 28-66 29-498 Sulphurous acid Chloride of ethyl Aldehyde 18-10 61-80 67-64 29-291 29-843 28-898 Pierre. 98-56 29-214 Sulphide of carbon 118-22 145-40 29-756 29-922 Pierre. Alcohol 178-82 29-922 212-00 29-922 242-42 29-528 640-00 29-922 Mercury 662-00 29-922 Kegnault. It will be observed that the first four of the bodies in the above table are gases at tem- peratures below the freezing point of water, one of them passing into the liquid state only at 126-22 F. below zero. The following method for ascertaining the boiling points of liquids is recommended by Prof. Kopp, and is par- ticularly applicable to cases where the liquid is expensive, or where only a small quantity can be obtained. A small test tube is fitted with a cork through which are bored two small holes. Through one of these a delicate ther- mometer is passed, and through the other a bent glass tube, open at both ends. A few scraps of recently heated platinum foil are placed in the test tube, and then the liquid, only a small quantity of which is required, is poured in. The scraps of platinum foil are for the purpose of furnishing starting points for the formation of the steam bubbles. The bulb of the thermometer is usually placed in