Concluding remarks. Castings in bell-metal are all more or less brittle; and, when recent, have a colour varying from a dark ash-grey to greyish-white, which is darkest in the more cupreous varieties, in which it turns somewhat on the yellowish-red or bluish-red. The larger the proportion of copper in the alloy, the deeper and graver the tone of the bells formed of it. The addition of tin, iron, or zinc, causes them to give out their tones sharper. Bismuth and lead are also often added to modify the tone, which each metal affects differently. The addition of antimony and bismuth is frequently made by the founder to give a more crystalline grain to the alloy. All these additions are, however, prejudicial to the sonorousness of bells, and of very doubtful utility. Rapid refrigeration increases the sonorousness of all these alloys. Hence M. D’Arcet recommends the ‘pieces’ to be heated to a cherry-red after they are cast, and after having been suddenly plunged into cold water, to be submitted to well-regulated pressure by skilful hammering, until they assume their proper form; after which they are to be again heated and allowed to cool slowly in the air. This is the method adopted by the Chinese with their gongs, &c., a casing of sheet-iron
being employed by them to support and protect the pieces during the exposure to heat. In a general way, however, bells are formed and completed by simple casting. This is necessarily the case with all very large bells. Where the quality of their tones is the chief object sought after, the greatest care should be taken to use commercially pure copper. The presence of a very little lead or any similar metal greatly lessens the sonorousness of this alloy; whilst that of silver increases it. This last metal has been detected in many old church bells remarkable for the richness of their tones—articles of silver plate having been cast into the crucibles of the founders, as votive offerings, by the pious Christians of former ages.
The specific gravity of a large bell is seldom uniform throughout its whole substance; nor can the sp. gr. from any given proportion of its constituent metals be exactly calculated owing to the many interfering circumstances. The nearer this uniformity is approached, or in other words, chemical combination is complete, the more durable and finer toned will be the bell.
In general it is found necessary to take about 1-10th more metal than the weight of the intended bell, or bells, in order to allow for waste and scorification during the operations of fusing and casting. See Bell, Bronze, Copper, &c.
BELLADON′NA (-dŏn′ă), [It., Sp., Port.; Eng., L., Ger.;[141] B. P.] Syn. Dead′ly night′shade, Dwale; Belledame, Belladonne, &c., Fr.; Tödtlicher Nachtschatten, Tollkersche, Tollkraut, Wolfskirsche, &c., Ger.; At′ropa letha′lis*, Sola′num furio′sum*, S. letha′le*, S. mania′cum*, S. melanocer′asus†, &c., L., Bot. var. Literally, fair lady; in materia medica, botany, &c., the usual name (adopted from the Ital.) of at′ropa belladonn′a (Linn.), an indigenous, poisonous, perennial, herbaceous plant, of the nat. ord. Solanæ (DC); Solanaceæ, Endl., (Lind.). It flowers in June and July, and its drooping, purple blossoms are common ornaments of our hedges and wastes where the soil is calcareous. It is supposed to be the ‘insane root’ of Shakespeare.[142]
[141] As a borrowed word.
[142] ‘Macbeth,’ Act I, Scene 3.
The parts of this plant used in medicine and pharmacy are the “fresh leaves and branches to which they are attached; also the leaves separate from the branches, carefully dried, of atropa belladonna; gathered, when the fruit has begun to form, from wild or cultivated plants in Britain” (B. P.).
Prop., Uses, &c. Every part of this plant contains ATRO′PIA, and is consequently highly poisonous. Every part, except the berries, is fœtid when bruised, and of “a dark and lurid aspect, indicative of its deadly narcotic quality.”[143] Its berries, which are of a glossy violet-black, and of the size of a small cherry, are sweet-tasted, and not at all nauseous. Children and tired travellers and soldiers, allured by their beauty and the absence of disagreeable flavour, have frequently been induced to eat them; but in all cases poisoning, often fatal, has followed the indulgence.[144] Belladonna is, however, in qualified hands a safe and most valuable medicine. Its chief use is as an anodyne, antispasmodic, sedative, and discutient, and particularly to diminish sensibility and allay pain and nervous irritation in a variety of diseases—neuralgia, arthritic and migratory rheumatic pains, painful ulcers, cancer, spasmodic rigidity, strictures, and contractions (especially of the bladder and uterus), angina pectoris, iritis, epilepsy, chorea, hooping-cough, hysteria, mania, fevers, phthisis, asthma, &c.; also as a prophylactic of scarlet-fever,[145] hydrophobia, and salivation, as a resolvent in enlarged and indurated glands (particularly when painful), as an agent to produce dilation of the pupil during surgical examinations and operations, &c., &c. It is employed both internally and externally, and in various forms, as is noticed under its ‘preparations’ elsewhere. Dose. Of the powder, 1⁄2 to 1 gr. twice a day, gradually and cautiously increased until dryness of the throat or dilation of the pupil occurs, or the head is affected.
[143] Pereira, 4th ed., vol. ii, 545.