Charcoal

CHARCOAL (Carbo), a product of incomplete combustion of animal or plant tissues. In medicine, wood and animal charcoal are used. Wood charcoal (Carbo ligni) is obtained by heating wood—most often birch, linden, or poplar—in the absence of air. Resinous tree species yield charcoal, usually contaminated with resinous substances, from which charcoal is difficult to wash. On heating, distillation products of the wood are released (in the form of wood vinegar, tar vapors, etc.), while the greater part of the carbon remains as charcoal together with traces of some organic substances and mineral components of the wood (ash). To remove the indicated impurities, charcoal is ground, repeatedly washed with hydrochloric acid and water, and then re-heated at a temperature not exceeding 850°. Animal charcoal (Carbo animalis) is obtained by heating animal substances in the absence of air. Depending on the starting material, bone charcoal is obtained by burning bones, blood charcoal from blood; the best charcoal is considered to be that obtained from meat and blood. Other types of charcoal—bread, wool, etc.—possess no advantages over wood and animal charcoal and are not encountered in practice. All varieties of charcoal are dry, black, fine powders, tasteless and odorless, insoluble in any of the known solvents. When charcoal is boiled with water, as well as with alcohol, the filtered liquids must be colorless and completely neutral on litmus. Charcoal should not contain sulfurous, chlorides, nitrates, or sulfates, organic compounds, calcium, iron, or heavy metal compounds; ash content should not exceed 5%, and for bone charcoal up to 6%. When burning charcoal, neither smoke, nor odor, nor flame should be released. The most important property of charcoal is its ability to absorb gases, coloring substances, fragrant materials, and to extract alkaloids, toxins, and enzymes from solutions. This property is explained by the presence of a highly developed surface, enormous porosity, and the ability to adhere to animal membranes. Charcoal adsorbs the indicated substances without entering into any chemical compounds with them. Charcoal was introduced into technique and medicine as an adsorbent by K. Scheele (1777) and by the St. Petersburg pharmacist (later an academician) T. E. Lovitz (1790). Activated charcoal possesses these properties to an even greater extent (see) as an indifferent colloidal substance in chemical relations, which, thanks to its ability to adhere to the skin and mucous membranes, forms a layer on their surface that mechanically protects from irritation and moderates the phenomena of inflammation. Charcoal is applied for the absorption of harmful agents: alkaloids and heavy metals (calomel) in poisonings; products of putrefaction and fermentation in the stomach and intestines, products of bacterial activity (toxins), tissue secretions—in wounds, combat poison gases, etc. Indications for the prescription of charcoal are: 1) infectious diseases of the gastrointestinal tract—dysentery, cholera, typhoid abdominal; stomach and intestinal ulcers, catarrhs, meteorism; poisonings by mushrooms, sausage, and fish poison. Dose: 1/2–1 teaspoon 3–4 times a day; in poisonings (strychnine, morphine, phenol) 20–75 mg per dose. The adsorbing capacity of activated charcoal is best manifested at a stomach pH not lower than 4–4.2; hence the expediency of prescribing it together with a 1% solution of sodium bicarbonate. The absorbed poisoning agents (alkaloids, toxins, ptomaines) after 2–2 1/2 hours charcoal begins to release them again and they may enter the intestine; therefore, a laxative is mandatory, preferably in the form of magnesium sulfate, simultaneously with the prescription of charcoal (2.0 mg per 10.0 g charcoal) or after 2–2 1/2 hours in a 30% solution—100–150 cm³. 2) Sterilized charcoal has found application in the form of powders for poorly granulating, purulent, and fetid wounds, for vaginal erosions, etc. 3) In gynecology, as a water suspension of 100–200 g for douching—in septic abortions, endometritis, puerperal septicemia. For purulent processes in the peritoneum, the injection of a suspension of activated charcoal in a solution of table salt into the abdominal cavity has been proposed. 4) For cardiac phenomena of the type of angina pectoris on the basis of improper gastric activity, the prescription of charcoal often aborts attacks. From the side effects (very rare) of charcoal taken per os, one can note the formation of dense charcoal fecal stones, a decrease in appetite. In laboratory practice, charcoal is used for adsorbing coloring substances, decolorizing, and deodorizing; activated charcoal, especially animal charcoal, is applied. 5) Activated charcoal occupies an outstanding place in the fight against combat poison gases for absorbing gases in masks, respirators, etc. Charcoal preparations: 1) wood charcoal—most often poplar, birch, and lilac; 2) blood charcoal; 3) charcoal from burnt bone; 4) activated wood and animal charcoal; 5) carbolen (Galen-Moscow)—activated wood charcoal in the form of powder and granules; 6) Bedlock lozenges—made from poplar charcoal; 7) incarbon [Merck—finest (colloidally ground)]—animal charcoal suspended in a protective colloid; administered intravenously in veterinary medicine to animals in septic labor, 40 cm³ per ampoule; 8) iod-incarbon—the same preparation with the addition of iodine; 9) carbenzym—colloidal plant charcoal with trypsin; applied for fermentation processes in the stomach and intestines, 0.5 g 4–6 times a day; also for poorly healing wounds with decomposition; the application of it subcutaneously, 0.5 g in 10.0 g of sterilized 0.5% sodium bicarbonate solution, has also been proposed; 10) carcoloid (Beringer)—colloidal preparation of animal charcoal, giving a highly dispersed suspension with water; for diarrhea, meteorism, and intoxications, 1 tablespoon 3–4 times a day; 11) argocarbon (Heiden)—wood charcoal with 0.5% silver; applied for meat poisonings and dyspepsias; dose 2.0–3.0 mg per dose 2–3 times a day; 12) carbolufen—charcoal with white clay and phenol.