Tests.—About a grain of hypochlorite of calcium, added to a little aqueous solution of carbolic acid, placed in a test-tube, produces after agitation, the addition of a few drops of ammonia, and the application of a gentle heat, a bright blue colour with a tinge of green. One drachm of the acid if pure completely dissolves on being shaken with half a pint of warm water.
Uses. The extraordinary antiseptic properties of carbolic acid have long been known, but its extended use has been delayed, owing to the difficulty experienced in obtaining it in considerable quantities. It is now, however, principally owing to the labours of the late Dr F. Crace Calvert, produced on a large scale, and this chemist has proposed its application to many valuable purposes. As a medical agent it seems to have all the useful properties of creosote in an exalted degree, with some peculiar actions of its own, and is being applied with marked success in the Manchester Royal Infirmary and similar institutions, in cases of chronic diarrhœa, obstinate vomiting (even after creosote has failed), and as a disinfecting wash for ill-conditioned ulcers and gangrenous sores. It has been said to have been used with
marked success internally as a remedy for hooping-cough. It has also been applied successfully in cases of foot-rot, a disease which annually carries off large numbers of sheep. It has been employed for the preservation of gelatin solutions and preparations of size made with starch, flour, and similar materials, and of skins and other animal substances. It appears to act strongly as an antiferment, and Dr Calvert states that it is one of the most powerful preventives of putrefaction with which he is acquainted. Commercial creosote is frequently nothing more than hydrated carbolic acid.
Professor Lister, of Edinburgh, adopting the germ theory of putrefaction, and regarding the putrid discharge from wounds as the result of the presence of atmospheric organisms which find a suitable nidus in the decomposing animal tissue exposed by the wound, seeks to exclude the access of these germs by the use of antiseptics, particularly of carbolic acid, the destructive action of which on living organisms is well known. He applies to the wounds dressings of gauze previously prepared with carbolic acid, additionally using as a lotion the acid, well diluted with water; whilst during the dressing of the wounds and the performance of surgical operations carbolic acid is diffused in the form of spray into the surrounding atmosphere with the object of destroying the germs floating in it.
Antidotes.—Calcined magnesia, or bicarbonate of soda, in milk after short intervals. In the absence of these, chalk, soap and water, or the plaster from the ceiling. Olive oil additionally. More than fifty per cent. of the carbolic acid manufactured is used for the purpose of preparing the following pigments and dye materials:—
1. Picric acid. 2. Phenyl brown. 3. Grenat soluble. 4. Coralline. 5. Azuline. These will be found described under Tar colours.
CAR′BON. C. Syn. Carbo′nium, Car′bo, L.; Charbon, Fr.; Kohlenstoff, Ger. An elementary or simple non-metallic solid body, very widely diffused through nature. Its purest and rarest form is that of the diamond. Nearly pure, it occurs very abundantly in the forms of graphite and anthracite. In combination with oxygen, as carbonic acid, it exists in the atmosphere and in the waters of most springs, also in limestone, marble, chalk, and dolomite. Combined with hydrogen, it enters largely into coal, peat, and lignite. It is an essential constituent of organic matter, and hence it has been termed the “organic element.” Charcoal, lamp-black, and coke, are more or less pure forms of carbon. By strongly igniting lamp-black in a covered crucible the element is obtained sufficiently pure for most chemical purposes.
It is best obtained purest by burning a jet of pure olefiant gas in an atmosphere of pure chloride, collecting the amorphous carbon deposited, and igniting in vacuo at a red heat.
Forms several chlorides, sulphides, &c., of which the following are the chief:—
Carbon, Protochloride of. Obtained from the sesquichloride by subliming it repeatedly through a tube filled with fragments of glass heated to redness. A transparent colourless liquid, with aromatic odour.