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is a still, into which 100 parts of black oxide of manganese (MnO2) and 150 parts of common salt (NaCl) are introduced by an opening in the top, which is closed by a water-joint; 185 parts f sulphuric acid (SO3), of specific gravity 1600, are then poured in by a funnel, and on the admission of steam within the jacket (i.e., between the outer and inner walls of the still), chlorine is evolved and issues through a tube at the head of the still into a stone or leaden chamber, there coming into contact with dry slaked lime in fine powder, with which the floor of the chamber is covered to the depth of about six inches. The chlorine is rapidly absorbed by the lime, which, when the absorption flags, is stirred from time to time by wooden rakes. The process must not be allowed to proceed too quickly, as much heat is evolved during the combination of the chlorine with the lime; and if the temperature of the chamber rises beyond 110° F., the power of combination is very much lessened. The chemical changes involved are not definitely known, but the resulting B. P. is a hypochlorite of calcium (CaCl2O2) with a variable proportion of chloride of calcium (CaCl,), and uncombined lime. B. P. is a grayish-white powder, with a strong odor like that of chlorine. See SODA, MANUFACTURE OF: MANGANESE: also HYDROCHLORIC ACID: HYPOCHLOROUS ACID. The B. P., prepared in either one or two stages, contains, when freshly and fully manufactured, generally 33-49 per cent. of chlorine, and the strength of any sample is determined by the process of Chlorometry (q.v.). It is used as a disinfectant, and in making chloroform. Its manufacture is one of the leading chemical industries.
BLEAK, a. blek [AS. blac, black: Ger. bleich; Dut. bleek, pale: Icel. bleikr, pale, wan]: cold; open; exposed; cheerless; solitary: N. a fresh-water fish, so named from its pale color, and whose scales are used in making artificial pearls. BLEAK'ISH, a. cheerless and open in a certain degree. BLEAKY, a. bleki, cold; chill. BLEAK'LY, ad. -l. BLEAK NESS, n. the quality of being bleak; exposure to cold and wind.
BLEAK (Leuciscus Alburnus): small fresh-water fish of the family of Cyprinide (q.v.), of a genus-name which, in N. Amer., we retain only in a tribe, Leuciscina. It is more than six or seven inches long; in general form it resembles the dace, but more elongated; the dorsal fin is fur
ther back, and the base of the anal fin is longer; the nose is pointed, the under jaw the longest; the scales are of moderate size, and beautifully striated; the back is of an olivaceous green color; the sides, belly, cheeks, and gill-covers. shining silvery white; all the fins nearly white. The tail is forked for half its length. The B. is found in many of
the rivers of Europe. On the inner surface of the scales of the B., as of white-bait, roach, dace, etc., a silvery substance, from which they derive their beautiful lustre, is found in such abundance as to be much used for making artificial pearls (q.v.), the white beads so common in ladies' head-dresses, and similar ornaments. That obtained from the scales of the B. is preferred to that of the roach and dace, but is inferior to that of the white-bait. It readily separates from the scales when they are soaked for a time in water, and settles to the bottom of the vessel. Small glass tubes are then dipped in it, and it is injected into thin hollow glass beads, of the requisite forms and sizes, which are placed in a current of air to dry, and are sometimes further filled with wax.-The B. is singularly liable to be infested by a species of tape-worm.
The B. is a very restless, active little fish, constantly playing about the top of the water, in search of small flies or other food. A small piece of bread cast into the water becomes speedily surrounded by a shoal of them darting to and fro at it. It is esteemed as delicate food, and is cooked in the same manner as sprats. The best way to catch B. is to angle for them with a single gentle and a light quillfloat, the bait being about a foot under water; they may be caught with very small flies, and all the more easily, if the hook be pointed with a gentle. They are so active, that the angler cannot strike too quickly, and where they abound they form good preliminary practice for the young fly-fisher. The neighborhood of running drains is a favorite resort for B. and the angler can soon determine if there be any about, by casting on the water a handful of bran, when, if there be any, they will immediately rise at it.
BLEAR, a. blër [Dan, blære, a blister: Low Ger. blarren, to cry or weep-hence, blair-ege, a red watery eye: prov. Sw. blira, to blink with the eyes: Sw. plire, to blink]: sore, watery, and tender in the eye: V. to make sore and tender; to blur; to dim. BLEAR ING, imp. BLEARED, pp. blērd. BLEAR EDNESS, n. state of one whose eyes are blear. BLEAR-EYED, having sore eyes; dim-sighted. BLEAR NESS, n. soreness of the eyes. TO BLEAR ONE'S EYES, in OE., to dim one's eyes; to deceive.
BLEAT, n. blet [an imitative word: Dut. blaten; Ger. blöken, to bleat as a sheep]: the cry of a sheep: V. to cry as a sheep. BLEATING, imp.: N. the cry of lambs or sheep. BLEAT ED, pp. BLA TANT, a. making a noise like a calf or sheep.
BLEB, n. blěb [an imitative word: Gael. plub, a round lump, a drop; allied to bulb-Lat. bulla, a bubble]: a drop of water; a blister; a vesicle; name applied to transparent bladders or blisters of the cuticle, appearing in some forms of fever, in erysipelas, and in disorders of the digestive apparatus. There are three varieties of B. recognized by physicians: 1. The mild B., which vary in size from a pea to a hazel-nut, occur on the face, neck or arms, and legs of teething infants, and of young persons who have indulged in unripe fruit. They generally burst, discharge the clear
fluid they contain, and heal up again in three or four days. 2. The tedious B., which most commonly affect aged and weakly persons, are seen as an eruption of numerous red elevations, which enlarge to the size of a pea, containing pale yellow serous fluid. These vesicles multiply to such an extent that the sufferer is disturbed at night from the irritation, and slight febrile attacks further debilitate him. 3. The solitary bleb generally selects old women for its victims, and appears, after much tingling of the skin, as one large vesication, and bursts in 48 hours, leaving a superficial sore.
The treatment consists in correcting the secretions, limiting the diet to what is farinaceous and easy of digestion, cooling drinks and tonics. For local treatment, the irratated surfaces are to be soothed by poultices and waterdressings.
BLEDSOE, blěď sō, ALBERT TAYLOR, LL.D.: 1809, Nov. 9-1877, Dec. 8: b. Frankfort, Ky.; d. Alexandria, Va.: West Point graduate, 1830, then lieut. Seventh Infantry till 1832; assistant prof. of mathematics in Kenyon College, 1834; rector of Prot. Episc. Church, Hamilton, O., and prof. of mathematics in Miami Univ., 1835-36; practiced law in Springfield, Ill., and in the supreme court at Washington, 1840-48; became prof. of mathematics in the Univ. of Mississippi, 1848, then in the Univ. of Virginia, 1824. Afterward a colonel in the Confederate service, he was soon made asst. sec. of war. In 1867, he began to publish The Southern Review. In 1871 he became a Methodist, and preached occasionally. He has published several theological works and political essays, and a Philosophy of Mathe
BLEED, v. bled [AS. bledan (see BLOOD)]: to lose blood by any means; to draw blood; to run sap from a tree. BLEED ING, imp.: N. a flow of blood; operation of letting blood; hemorrhage: ADJ. flowing with blood or juice. BLED, pp. bled. BLEED ER, n. one who bleeds.
BLEEDING (hemorrhage): one of the most serious ac cidents which can happen to an animal, and giving rise to a grave complication in surgical operations. As there is but a limited quantity of blood in the body, and as the sudden escape of a large portion of it may cause death, every one should be instructed as to the measures most efficient for preventing a dangerous loss of blood. B. may be either from a wounded artery or vein, or from a raw surface; and it may be in the form of a general oozing from the surface of a sore or a mucous membrane.
Arterial B. is recognized by the florid redness of the blood, and by its issuing from the cut vessel per saltum or by jerks. There are exceptions to this, however, When
an artery has been tied, and bleeding occurs from below the ligature, the flow of blood is continuous, and of a dark color.
If a large artery be wounded, the first gush of blood may prove fatal, but in general the patient faints, and nature takes advantage of the respite to place the cut artery in circumstances as favorable as possible to the preservation of life; viz., the artery draws up within its sheath (see ARTERY); the blood, no longer impelled vigorously by the heart, clots between the cut end and the cellular tissue surrounding it; the inner and middle coats not only retract but contract, and another clot forms within the arterial tube. These clots--which, with the faintness and the contraction and retraction of the artery, are termed natural hemostatics (blood-stoppers)—are sufficient in many cases to prevent a recurrence of the B.; but such a happy concurrence is not to be depended on, and there should be preparation to adopt some of the many surgical or artificial means for restraining the flow of blood till adhesion (q.v.) can occur between the cut surfaces of the coats of the artery. The principal surgical means are:
Immediate pressure, which may be applied by pressing the finger-tip on the place whence the blood is seen to flow, and may be kept up by pads of lint, or a coin of convenient size wrapped in cloth, and secured with a bandage to the part.
Pressure on the artery above, or as it comes to the cut part. This requires some knowledge of anatomy, but not more than any intelligent person may easily acquire. Thus, pressure on the inside of the arm, about midway between its front and back, will press the brachial artery (q.v.) against the bone, and arrest any bleeding from wounds of the forearm and hand. Pressure on the middle of the groin with a thumb placed crosswise will control the stream of blood in the femoral artery, so that none can cscape from any wound below where the pressure is made.
Pressure on the course of the vessel may be very efficiently effected by tying a handkerchief round the limb above where it is injured, and then inserting a stick, and twisting it sufficiently tight. This is the principle of the original tourniquet, which was invented by Morel, a French surgeon, at the siege of Besançon, 1674. He got the idea from seeing how carriers tightened the ropes which se
cured bales of goods on their carts. It has been modified from time to time. At present it consists of a strap and buckle, a pad which may be adjusted over the course of the artery wounded, or likely to be cut in an operation, and a screw by which the strap may be tightened as the surgeon may deem necessary. See TOURNIQUET. The objections to pressure as a means of arresting hemorrhage are, that it is very painful, that it includes the vein, and thereby engorges the limb with blood, and may cause mortification, if long continued.
'Actual' cautery, or hot iron, is occasionally useful in bleeding from a bone, or at some points where pressure cannot be efficiently applied. It is the oldest method of stopping bleeding, and until the 18th c. was much in use; but its abuse, and the natural horror felt for it by both patient and surgeon, have almost banished it from the list of surgical hemastatics. If used, the iron should be at white heat, the wound pressed for an instant, and then the iron should be held in contract with the bleeding vessel. It causes an eschar or slough, with shrivelling of the artery; and if the latter be small, it effectually stops the bleeding, until the eschar drops off, when the vessel may be found still pervious at the wounded part, and the danger of bleeding be as great as at first.
Ligature, or tying the artery, is a very old method of arresting hemorrhage, and certainly the best. It was not used generally, however, in operations until improved anatomical knowledge and more efficient tourniquets allowed surgeons the time necessary for its application. See LIGATURE.
Another method was introduced by Sir James Y. Simpson of Edinburgh, and was termed by him Acupressure (q.v.), or pressure from a long needle or pin inserted from without, so as to press the artery between it and the tissues. The pins are removed after 24-48 hours. This plan (superseded by the catgut ligature, which can be absorbed) promised to supersede the older kinds of ligature, especially in amputations, where the vessels can be easily secured, and where occasionally they are found so brittle from disease (see ATHEROMA) as to break under the pressure of a thread. It is not now in common use by surgeons, having been superseded by hæmostatic forceps.
Venous B. is recognized by the dark color of the blood, and its continuous flow. Pressure is generally sufficient to arrest it, and it should be applied directly over the wounded part. If pressure be insufficient to stop the flow, the cut end should be seized with a pair of hæmostatic forceps and tied with cat-gut, using every antiseptic precaution to prevent the entrance of, or to destroy, germs that may be present. The fear of tying a vein, prior to the era of antiseptic or aseptic surgery, was perhaps well founded; but veins can now be tied in entire safety, though the surgeon must be perfectly sure of his antiseptic precautions, and if they be not cut quite through, he may pick up the cut edges in a forceps, and tie them so as still to permit a flow of blood through the vein.