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and said, that his sovereign, equitable as he was, could not, with-out injustice, grant a pension to an author like hitnself, just ascend-ing Parnassus, and take it from Corneille, who had so long beenseated on the summit; that he entreated her, for the honour of theking, to prevail on his majesty rather to strike oft his pension,than to withdraw that reward from a man whose title to it was in-comparably greater ; and that he should more easily console him-self under the loss of that distinction, than under the affliction ofseeing it taken away from such a poet as Corneille. This mag-nanimous application had the success which it deserved, and itappears the more noble, that the rival of Corneille was the inti-mate friend of Boileau. The best edition of his works is that ofDurrad in 1747, 5 vols. 8vo.
BOILING , or EBULLITION, the bubbling up of any fluid.The term is most commonly applied to that bubbling which hap-pens by the application of tire, though that which ensues on themixture of an acid and alkali is sometimes also distinguished bythe same name. Boiling , in general, is occasioned by the dis-charge of an elastic fluid through that which is said to boil; andthe appearance is the same, w hether it is common air , fixed air,or steam, that makes its way through the fluid. The boiling ofwater is proved by Dr. Hamilton of Dublin, in his essay on theascent of vapour, to be occasioned by the lowermost particles ofthe water being heated and rarified into vapour by reason of thevicinity of the bottom of the containing vessel; in consequence ofwhich, being greatly inferior in specific gravity to the surround-ing fluid, they ascend with great velocity, and lacerating andpushing up the body of water in their ascent, give it the tumultu-ous motion called boiling. This is evidently occasioned by steam,and not by particles of air or fire, as some have imagined. Apleasing experiment is related by that elegant and ingenious phi-losopher, the present bishop of LlandafT, which is illustrative of thenature of boiling in general, and particularly of what has been justadvanced. With an intent of exhibiting a striking instance ofthe increase of dimensions produced by heat in fluids, he took aglass-vessel not unlike the thermometer in form ; the bulb con-tained above a gallon, the stem had a small diameter, and wasabout two feet in length. This vessel he filled with boiling waterto the very top of the stem, and corked it close with a commoncork. The water and the cork were at first contiguous, but as thewater cooled it contracted, and sunk visibly in the stem ; and thusthe first intention of the experiment was answered. But here anunexpected phenomenon presented itself. The water, though it■was removed from the fire, though it was growing cold, and hadfor some time entirely ceased from boiling, began to boil veryviolently. When a hot iron was applied to that part of the stem,through which the water in contracting itself had descended, theebullition presently ceased ; it was renewed when the iron wasremoved ; and it became more than ordinarily violent, when, bythe application of a cloth dipped in cold water, that part was cool-ed. To account for these appearances, it is only necessary, to re-collect, that by the sinking of the water in the stem, a kind of va-cuum is left between its surface and the cork ; the water thereforenecessarily boils with a lower degree of heat than it would underthe pressure of the atmosphere. The space between the cork and 1the water is not, however, a perfect vacuum : it is occupied eitherby the vapour of the water, or by a small portion of air, or byboth. Heat increases the elasticity both of air and vapour, andthus augments the pressure upon the surface of the water ; hencethe ebullition ceases upon the application of the hot iron. Cold,on the contrary, diminishes the elasticity of the air, and condensesvapour ; and thus the pressure upon the surface being lessened bythe application of a cold cloth, the ebullition of the water becamemore violent. ’1 he heat of tlre water when it ceased boiling was130 degrees. Every particular liquid has a fixed point at whichboiling commences, and this is called the boiling point of theliquid. Thus water begins to boil when healed to 212 degrees.Alter a liquid lias begun to boil, it never becomes hotter, how-ever strong the.fire may be to which it is exposed. A strong heat,indeed, makes it boil more rapidly, but does not increase its tem-perature., This fact was first observed by Dr. Hooke. The fol-lowing table shews the boiling point of a number of liquids:
Bodies. Boiling point.
jEther. 98
Ammonia.140
Alcohol. .,.,17(1
Bodies. Boiling point.
Water.212
M uriate of lime.230
Nitric acid.248
Sulphuric acid.590
Phosphorus.554
Oil of turpentine.560.
Linseed oil.600
Mercury.600
The boiling point, however, is found to depend on the degree ofpressure to which the liquid is exposed. If the pressure is dimi-nished, the liquid boils at a lower temperature ; if it is increased,a higher temperature is necessary to produce ebullition. Fromthe experiments of professor Robison, it appears that, in a vacuum,all liquids boil about 145 degrees lower than in open air, under apressure of 30 inches of mercury ; therefore water would boil invacuo at 67 degrees, and alcohol at 34 degrees. In Papin’s di-gester, the temperature of water may be raised to 300 degrees, oreven 400 degrees without ebullition ; but the instant that this greatpressure is removed; the boiling commences with prodigious vio-lence. See Evaporation.
Boiling, in the culinary art, is a method of dressing animalfood, vegetables, &c. by coction in hot water, for the purpose ofremoving their natural crudities, and rendering them more easy ofdigestion. By too much boiling, however, flesh is deprived of aconsiderable part of its nourishing juice, as the gelatinous substanceof the meat is extracted, and incorporated with the water, whilethe spirituous and balsamic particles are dissipated by evapora-tion. The culinary process of stewing is more profitable, espe-cially if conducted in close vessels, as it is better calculated to pre-serve and concentrate the most substantial and nutritious parts ofanimal food.
Boiling, in trade and manufactures, is a preparation given todivers sorts of bodies by making them pass over the fire, chieflyin water, though sometimes in other liquors. In this sense wespeak of the boiling of salt, sugar, copperas, linens, See.
Boiling to Death, [calduriii dccoqu.ere,'] in the middle age,was a punishment inflicted on thieves, false coiners, and someother criminals.
BOINITZ, or BOITNITZ, a town of Upper Hungary, inthe county of Zell, remarkable for its baths and the quantity ofsaffron that grows about it. Lon. 19. 10. E. Lat. 48. 42. N.
BOIORUM DESERT A, a district of Pannonia, now calledWeinerwald, in Lower Austria .
BOISEAU, a French corn measure ; equal to about twobushels and half a peck English .
BOIS-LE-DUC , called by the Dutch Hertogenbosch, a townin Dutch Brabant, 22 miles E. by N. of Breda. Lon. 5. 16. E.Lat. 51.40. N.
BOKHARA, a city of Tartary in Asia , and capital of GreatBukharia, situated one day’s journey to the N. of the river Jehmi,or Amu. Lon. 62. 55. L. Lat. 39. 15. N.
JBOKHAIIIA. See Bukharia.
BOLES, in natural history, viscid earths, less coherent andmore friable than clay; more readily uniting with water, and morefreely subsiding from it. They are sott and unctuous to thetouch ; adhere to the tongue ; and by degrees melt in the mouth,impressing a light sense of astringency. These earths, made intolittle masses, and stamped with certain impressions, are calledterra sigillatx. They have been recommended as astringent, su-dorific, and alexipharmic ; but these and many other virtues thathave been ascribed to them appear to have no foundation. Theyare still, however, prescribed in fluxes and complaints ol theprinravite. There are a great variety of them. The principalare the following:
1. Bole, Armenian, when pure, is of a bright red colourwith a tinge of yellow : it is one of the hardest and most compactbodies of this class, and not smooth and glossy like the others,but generally of a rough anti dusky surface. It does not effer-vesce with acids, though some part of it is dissolved by all of
2. Bole, Bohemian, is of a yellow colour, with a cast of
red, and generally of a flasky texture. It is not acted on byacids. . ,
3. Bole, French , is of a pale red colour, variegated with
irregular
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