Page:The New International Encyclopædia 1st ed. v. 04.djvu/232

* CARBOLIC ACID. 192 CARBONARI. the air; during operations the air in the neigh- borhood of the wound was kept antiseptic by a line spray of a woak tarboliearid solution. The practice was introduced by Li^^tvr, but is at present considered superfluous, and even some- what dangerous, as it may give rise to poison- ing. Carbolic acid is generally used to disinfect surgical instruments, bed-linen, fecal discbarges, walls and floors, drains, etc. The crcsol con- tained in crude carbolic acid is itself quite use- ful for these purposes. Carbolic acid is furtlier used in itching of the skin, as a stimulant to ulcers, as a gargle, for burns, etc. Ilypodermi- calh' it has been employed in hemorrhoids, ery- sipelas, synovitis, inflamed liirsr. bubo, poisoned wounds, glandular swellings, etc. Internally it has been used in flatulent dyspepsia ( in the form of sul])hn-carbolate of soda), in typhoid fever, and in diabetes due to disease cf the liver. It has been used hypodermically, by injection into the lunsr-substance, and as a s])ray in tubercu- losis of the lungs, but without nnich benefit, al- though the spray allays cough. CARBON ILat. cirbo, coal). One of the most important chemical elements. It exists in large quantities, both in the free state and in combination with other substances. It occurs unconiliincd in the mineral grajibite. or black lead, and in the diamond, which is pure crystal- lized carbon. It is much miu'e abundant, how- ever, in a state of combination. United with oxygen, it occurs as carbonic acid in the atmos- phere and in natural water, and it is similarly combined in limestone, dolomite, and ironstone. In coal it is found combined with hydrogen and oxygen, and in plants and animals it occurs as one of the elements building up wood, starch, gum, sugar, oil. bone (gelatin), and flesh (fibrin). Indeed, there is no other element which is so char- acteristic of plant and animal organisms as car- bon. Carbon is often set free by the decomposi- tion of organic matter. Thus charcoal fomis during the imperfect combustion of wood. Many volatile organic substances, especially those rich in carbon, burn with a sn)oky flame, soot being nothing but finely divided carbon. Tlie decom- position of vegetable refuse under water gives rise to the formation of peat. The formation of humus (black earth) is due to the carbonization of vegetable matter in moist air. At elevated temperatures carbon combines directly with oxygen, sulphur, silicon, and many metals. (See CARniDES.) If heated with oxygen or with a strong oxidizing agent like nitric acid, carbon forms carbonic-acid gas; if the amount of avail- able oxygen is, however, small, carbonic oxide is produced, which contains a jnuch lower per- centage of oxygen. At ordinary temperatures carbon is, like nitrogen, extremely inert: so much .so that it is customary to diar the ends of piles of wood which are to be driven into the ground, so as by this coating of nfm-decaying carbon to preserve the wood. In a similar man- ner, the interior of wooden vessels intended to hold water during sea voyages is charred (coat- ed with carbon) to keep the wood from passing into decay and thus to preserve the water 'sweet.' Three allotropic modifications of carbon are known — viz.. amorphous carbon, graphite, and diamond. The chemical identity of these sub- stances is proved by l)>irning them, equal quanti- ties yielding precisely the same amount of car- bonic acid, though there is a marked difference in the readiness with wbich they burn. Arti- ficial amorplums carbon takes fire readily; gra- phite is so non-combustible that crucibles made of this material withstand a high heat for a con- siderable length of time; diamond comi)letely resists most ordinary modes of setting fire to it, but can be burned readily in an alnuisphere of pure oxygen, by means of the electric current. The specific gravities, the hardness, and other physical i)roperties of the three allotropic modi- fications of carbon are likewise very dilTerent. JIany experiments have been made with the ob- ject- of transforming the less valuable varieties of carb(m into diamond. Only very miiuite quan- tities of diamond have hitherto lieen made arti- ficially. After diamond was found to be ac- companied in meteors by iron and sulphur, the distinguished French chemist Charles Friedel endeavored to produce diamond by heating cast iron rich in carbon with suljjhur, at 500° C, when a small amount of an exceedingly hard substance was produced ; the quantity was. how- ever, so slight that it was impossible to demon- strate conclusively the formation of diamond. Kven by the use of the electric furnace. Moissan, in 1893, succeeded in obtaining only traces of diamond. Graphite, on the contrary, is read- ily formed from charcoal by heating; this is the elTect, for insti)nce, of the .iction of a pow- erful galvanic current on charcoal. Pure carbon may be prepared by charring organic substances, such as sugar, that leave no ash; to prepare it from lampblack, this substance is carefully washed with alcohol and ether and heated to a liigh temperature. I,am])black is largely used for making black paint, printers' ink, etc. : it is obtained by burning substances rich in carbon, such as tar. natural gas, etc. Graphite, which occurs in large quantities in nature, is used for the manufacture of pencils, after being powdered and freed from earthy matter. The carbons used in electric lighting are likewise made of graphite, which is obtained in a very dense form by mix- ing powdered coal with syrup to a pasty mass, giving the latter the desired shape, and applying an intense heat. Charcoal has been utiliz<'d for making the carbonic acid used in sugar-works, and for other purposes in the arts; it is em- ployed for decolorizing solutions (see Hone- black) ; and as, when dry, it readily absorbs gases, it is used as a disinfectant and deodorant. It is also sometimes used in medicine as an anti- dote against vegetable poisons, such as opium, aconite, etc. Carbon is infusible and insoluble in any known liquid. The atomic weight of the element is 12, and it is denoted in cliemical for- mulas by the symbol C. Tlu' nadecule of carbon probably constitutes a complex system of atoms. See CiiARcoAi. ; CoAi. ; Graphite ; Diamond; Carbox CoMPovxns; Valency. CARBONARI, kiir'bo-nii're (It., pi. of cnrbu- nar(j, from Lat. carbonari us, charcoal-burner, collier, from carbo, coal). The name of a secret political society which took an active part in the struggle for Italian liberty and unity. Its e.xistence and character first be- came in some degree known in 1815. The constitution, as well as the precise objects of the Carbonari, still remains in a great measure secret, though there have been printed instructions, catechisms, statutes, and rituals of