Open main menu
This page has been proofread, but needs to be validated.
692
BELLABELLA—BELLADONNA

Troyte on Change-Ringing; The Duffield Method, by Sir A. P. Heywood, Bart., its inventor. Somewhat prior to these are various works by the Rev. H. T. Ellacombe, inventor of a chiming apparatus which bears his name, and a pioneer in belfry reform. Among these are accounts of the church bells of Devon, Somerset and Gloucester, and pamphlets on Belfries and Ringers, Chiming, &c.; much of their contents being summarized in The Ringer’s Guide to the Church Bells of Devon, by C. Pearson (1888). A Glossary of Technical Terms used in connexion with church bells and change-ringing was published (1901) under the auspices of the Central Council of Church Bell Ringers. On the history of church bells and customs connected with them much curious information is given in North’s English Bells and Bell Lore (1888). By the same author are monographs on the church bells of Leicestershire, Northamptonshire, Lincolnshire and Hertfordshire. There are similar works on the church bells of Suffolk and Cambridgeshire, by Dr Raven; of Huntingdonshire, by the Rev. T. M. N. Owen; and on the church bells of Essex, by the Rev. C. Deedes. A compilation and summary of many data of bell-lore will be found in A Book about Bells, by the Rev. G. S. Tyack; and in a volume by Dr Raven in the “Antiquary’s Books” series (Methuen, 1906), entitled The Bells of England, which deals with the antiquarian side of bell-lore. See also Quarterly Review, No. cxc. (September 1854); Windsor Magazine (December 1896); Lord Rayleigh’s paper “On the Tones of Bells” in the Phil. Mag. for January 1890; and a series of articles from the Guardian, reprinted as a pamphlet under the title, Church Bells and Bell-ringing.

 (T. L. P.) 

House Bells.—Buildings are commonly provided with bells, conveniently arranged so as to enable attendants to be summoned to the different rooms. In the old system, which has been largely superseded by pneumatic and still more by electric bells, the bells themselves are of the ordinary conical shape and are provided with clappers hung loosely inside them. Being supported on springs they continue to swing, and therefore to give out sound as the clapper knocks against the sides, for some time after they have been set in motion by means of the strings or wires by which each is connected to a bell-pull in the rooms. These wires are generally placed out of sight inside the walls, and bell-cranks are employed to take them round corners and to change the direction of motion as required. A lightly poised pendulum is often attached to each bell, to show by its motion when it has been rung. In pneumatic bells the wires are replaced by pipes of narrow bore, and the current of air which is caused to flow along these by the pressing of a push-button actuates a small hammer which impinges rapidly against a bell or gong. An electric bell consists of a small electro-magnet acting on a soft iron armature which is supported in such a way that normally it stands away from the magnet. When the latter is energized by the passage of an electric current, the armature is attracted towards it, and a small hammer attached to it strikes a blow on the bell or gong. This “single stroke” type of bell is largely used in railway signalling instruments. For domestic purposes, however, the bells are arranged so that the hammer strikes a series of strokes, continuing so long as the push-button which closes the electric circuit is pressed. A light spring is provided against which the armature rests when it is not attracted by the electro-magnet, and the current is arranged to pass through this spring and the armature on its way to the magnet. When the armature is attracted by the magnet it breaks contact with this spring, the current is interrupted, and the magnet being no longer energized allows the armature to fall back on the spring and thus restore the circuit. In this way a rapid to and fro motion is imparted to the hammer. The electric current is supplied by a battery, usually either of Leclanché or of dry cells. One bell will serve for all the rooms of a house, an “indicator” being provided to show from which it has been rung. Such indicators are of two main types: the current either sets in motion a pendulum, or causes a disk bearing the name or number of the room concerned to come into view. Each push must have one wire appropriated to itself leading from the battery through the indicator to the bell, but the return wire from the bell to the battery may be common to all the pushes. Bells of this kind cease to ring whenever the electrical continuity of any of these wires is interrupted, but in some cases, as in connexion with burglar-alarms, it is desirable that the bell, once set in action, shall continue to ring even though the wires are cut. For this purpose, in “continuous ringing” bells, the current, started by the push or alarm apparatus, instead of working the bell, is made to operate a relay-switch and thus to bring into circuit a second battery which continues to ring the bell, no matter what happens to the first circuit.  (H. M. R.) 

BELLABELLA, the common name (popularized from the Indian corruption of Milbank) for a tribe of Kwakiutl Indians at Milbank, British Columbia, including the subtribes Kokaitk, Oetlitk and Ocalitk. They were converted to Christianity by Protestant missionaries, and number about 300.

BELLACOOLA or Bilqula, a tribe of North American Indians of Salishan stock, inhabiting the coast of British Columbia. They number some 300.

BELLADONNA (from the Ital. bella donna, “beautiful lady,” the berries having been used as a cosmetic), the roots and leaves of Atropa belladonna, or deadly nightshade (q.v.), widely used in medicine on account of the alkaloids which they contain. Of these the more important are atropine (or atropia), hyoscyamine, hyoscine and belladonine; atropine is the most important, occurring as the malate to the extent of about 0.47% in the leaves, and from 0.6 to 0.25% in the roots.

Atropine, C17H23NO3, was discovered in 1833 by P. L. Geiger and Hesse and by Mein in the tissues of Atropa belladonna, from which it may be extracted by means of chloroform. By crystallization from alcohol it is obtained as colourless needles, melting at 115°. Hydrolysis with hydrochloric acid or baryta water gives tropic acid and tropine; on the other hand, by boiling equimolecular quantities of these substances with dilute hydrochloric acid, atropine is reformed. Since both these substances have been synthesized (see Tropine), the artificial formation of atropine is accomplished. Atropine is optically inactive; hyoscyamine, possibly a physical isomer, which yields atropine when heated to 108.6°, is laevorotatory.

Medicine.—The official doses of atropine are from 1⁄200 to 1⁄100 grain, and the sulphate, which is in general use in medicine, has a similar dose. It is highly important to observe that the official doses of the various pharmacopoeias may with safety be greatly exceeded in practice. They are based on the experimental toxic, as distinguished from lethal dose. A toxic dose causes unpleasant symptoms, but in certain cases, such as this, it may require very many times a toxic dose to produce the lethal effect. In other words, whilst one-fiftieth of a grain may cause unpleasant symptoms, it may need more than a grain to kill. So valuable are certain of the properties of atropine that it is often desirable to give doses of one-twentieth or one-tenth of a grain; but these will never be ventured upon by the practitioner who is ignorant of the great interval between the minimum toxic and the minimum lethal dose. It actually needs twenty to thirty grains of atropine to kill a rabbit: the animal is, however, somewhat exceptional in this regard. The most valuable preparations of this potent drug are the liquor atropinae sulphatis, which is a 1% solution, and the lamella—for insertion within the conjunctival sac—which contains one five-thousandth part of a grain of the alkaloid.

Pharmacology.—When rubbed into the skin with such substances as alcohol or glycerine, which are absorbed, atropine is carried through the epidermis with them, and in this manner—or when simply applied to a raw surface—it paralyses the terminals of the pain-conducting sensory nerves. It acts similarly, though less markedly, upon the nerves which determine the secretion of the perspiration, and is therefore a local anaesthetic or anodyne and an anhidrotic. Being rapidly absorbed into the blood, it exercises a long and highly important series of actions on nearly every part and function of the nervous system. Perhaps its most remarkable action is that upon the terminals of nearly all the secretory nerves in the body. This causes the entire skin to become dry—as in the case of the local action above mentioned; and it arrests the secretion of saliva and mucus in the mouth and throat, causing these parts to become very dry and to feel very uncomfortable. This latter result is due to paralysis of the chorda tympani nerve, which is mainly responsible for the salivary secretion. Certain nerve fibres from the sympathetic nervous system, which can also cause the secretion of a