Cooley's Cyclopaedia of Practical Receipts Volume I Part 64

_Tests._--1. Nitric acid forms with it a yellow solution:--2. With cold sulphuric acid it gives a colourless solution, which becomes red only when heated:--3. Aqueous solutions of atropia and its salts are--_a_, turned red by tincture of iodine--_b_, gives a citron-yellow precipitate with terchloride of gold--_c_, a flocculent whitish precipitate with tincture of galls, and--_d_, a yellowish-white one with bichloride of platinum:--4.

Heated with caustic pota.s.sa or soda, it suffers decomposition, and ammonia is evolved:--5. A weak solution cautiously applied to the eyelid or conjunctiva, produces dilation of the pupil lasting for several hours.

_Pur., &c._ Alkaloid prepared from the root of atropa belladonna.

Crystals; white, in the form of prisms; soluble in water and rectified spirit. It leaves no ash when burned with free access of air (B. P.).

_Phys. eff._ It is a very powerful narcotico-acrid poison.[103] Its effects are similar to those of belladonna, but considerably more powerful. "A very minute (imponderable) quant.i.ty applied to the eye is sufficient to dilate the pupil." (Pereira.) The 1/12 to 1/10 gr. often causes very serious effects in the human subject. The 1/6th of a grain accelerates the pulse, affects the brain, causes dryness of the throat, difficulty of deglut.i.tion, dilation of the pupil, dimness of sight, giddiness, strangury, numbness of limbs, sense of formication in the arms, rigidity of thighs, depression of pulse, and sometimes feebleness or loss of voice. These symptoms continue for from 12 to 24 hours. In larger doses death ensues.

[Footnote 103: A "cerebro-spinal poison."--Taylor.]

_Ant., &c._ These may be similar to those described under BELLADONNA and ALKALOID.

_Uses._ Chiefly as an external agent, as a subst.i.tute for belladonna, to cause dilation of the pupil; and as a local anaesthetic or anodyne, especially in facial neuralgia. Internally, it has been occasionally given in hooping-cough, ch.o.r.ea, and a few other nervous diseases.--_Dose_, 1/30 gr., gradually increased to 1/20, or, occasionally, even 1/15 gr. in solution, or made into a pill with liquorice powder and honey, or syrup, or used endermically; for a collyrium, 1 gr. to water 1 oz., a few drops only being applied to the eye at a time, the greatest caution in each case being observed. It is also employed to make the sulphate. In dispensing it a single drop of acetic acid, or dilute sulphuric acid, will be found to facilitate and ensure its perfect solution. See BELLADONNA and BELLADONINE.

=Atropia, Sul'phate of.= _Syn._ ATRO'PIA SUL'PHAS, L. _Prep._ (B. P.) Take of atropia, 120 _gr._; distilled water, 4 _fl. dr._; diluted sulphuric acid, a sufficiency.

Mix the atropia with the water and add the acid gradually, stirring them together until the alkaloid is dissolved and the solution is neutral.

Evaporate it to dryness at a temperature not exceeding 100.

_Characters and Tests._--A colourless powder, soluble in water, forming a solution which is neutral to test-paper, and when applied to the eye dilates the pupil as the solution of atropia does. It leaves no ash when burned with free access of air.

Intended for external application. It is a powerful poison.

_Uses, &c._ The same as those of the pure alkaloid.--_Dose_, 1/25 to 1/20 gr., either in solution or pills; 1 to 3 gr. to water 1 fl. oz., as a collyrium, of which a few drops seldom fail to produce full dilation of the pupil in about a quarter of an hour; 1 to 2 gr. to lard 1 dr. forms an excellent ointment in neuralgic affections.

_Obs._ Sulphate of atropia (which is intended for external use only) is rather difficult to crystallise, as it has a tendency to a.s.sume an amorphous or gum-like condition. It is more soluble than the pure alkaloid; and, like it, is a terrific poison.

=ATROPIA, VALERIANATe.= The Paris Codex directs this salt to be prepared as follows:--Dissolve valerianic acid in ether, and add atropia just sufficient to saturate the acid. Let the ether evaporate.

=ATROP'IC ACID.= _Syn._ ACIDUM ATROP'Ic.u.m, L. The name given by Richter to a volatile crystallisable substance, possessing acid properties, found in atropa belladonna or deadly nightshade. In many respects it resembles benzoic acid, from which, however it is distinguished by not precipitating the salts of iron.

=ATROPI'NA, At'ropine.= See ATROPIA.

=AT'TAR.= See OTTO and VOLATILE OILS.

=ATTELETTES= (-lets'). [Fr.] In _cookery_, small skewers, generally of silver, with ornamental heads. The term is also applied to small dishes (ENTReES, &c.) in which the articles are mounted on attelettes. Small fish, as smelts, are often served in this way. See AIGUILLETTE.

=ATTEN'UANT= (-u-ant). _Syn._ ATTEN'UANS, L.; ATTeNUANT, Fr.; VERDuNNEND, Ger. That makes thin, or less dense or viscid; diluting. In _medicine_, applied to remedies (ATTEN'UANTS, SPANaeM'ICS) which are supposed to act by thinning, diluting, or impoverishing the blood.

=ATTENUA'TION.= _Syn._ ATTENUA'TIO, L.; ATTeNUATION, Fr.; VERDuNNUNG, Ger.

A thinning or diminishing; a reducing in consistence. In _medicine_, see the adj. (_above_); in _brewing_, the decrease of the density of worts during fermentation, arising from the gradual conversion of their 'saccharine' (sugar) into alcohol. See BREWING, DISTILLATION, WORTS, &c.

=ATTRAC'TION.= [Eng., Fr.] _Syn._ ATTRAC'TIO, L.; ANZIEHUNG, Ger. The power that draws together matter and resists its separation. That force which attracts bodies towards the centre of the earth, and which keeps on its surface those that are movable, is called GRAVITY, or the attraction of gravitation. It is exerted at sensible, often at immense, distances, and determines the figure and motions of the planets and comets, and causes the descent of heavy bodies to the ground. This force it is which confers the property of weight upon matter.

That force which unites particles of the same kind of matter, so as to cause them to a.s.sume the condition of solid or liquid ma.s.ses, _e.g._ particles of chalk to form a ma.s.s of chalk, particles of water to form a ma.s.s of water, is called COHESION, or the ATTRACTION OF COHESION. That force which binds together different substances without changing their properties, as when paint sticks to wood, ink to paper, &c., is called ADHESION, or the ATTRACTION OF ADHESION. CAPILLARY ATTRACTION is a modification of adhesion, and is characterised by being exerted between liquids and the internal surfaces of tubes and pervious bodies. The absorption of water by a sponge, the ascent of oil in the wick of a lamp, are examples of this power. The CHEMICAL FORCE or AFFINITY differs from all other kinds of attraction in being exerted between definite and constant quant.i.ties (atoms) of matter, usually of dissimilar natures, and producing combinations possessing properties different from those of their components. (See AFFINITY.) This force, as well as cohesion and adhesion, is exerted at distances so small as to be immeasurable.

The terms ELEC'TRIC ATTRACTION and MAGNET'IC ATTRACTION are employed in _physics_ to denote phenomena which we imperfectly understand, and which operate between bodies at sensible distances, and simulate those of the attraction of gravitation.

=ATTRI"TION= (trish'-un). [Eng., Fr.] _Syn._ ATTRI"TIO, L.; ABREIBUNG, AUFREIBUNG, Ger. In _mechanics_, the wearing away of parts by friction. In _medicine_, a graze, abrasion, or solution of continuity of the cuticle, or the act which causes it. In _surgery_, the crushing or tearing away of any exterior portion of the body by violence. See ABRASION, ANTI-ATTRITION, FRICTION, &c.

=AURANTIA'CEae= (-she-e). [Lat.; DC.] The orange tribe. In _botany_, an extensive and important natural order of exogenous trees and shrubs, found exclusively in the temperate and tropical parts of the Old World, and unknown in a wild state in America. The fruit is pulpy, succulent, sub-acid, and eatable, and separated into cells by membranous part.i.tions, and is covered with a leathery aromatic skin or rind. Some of the genera embrace plants of great beauty and utility. A few of the Indian species are climbers. The genus CIT'RUS, which includes the orange, lemon, citron, lime, bergamot, and shaddock, is that best known in Europe.

=AURAN"TIIN= (-she-in). _Syn._ HESPERIDIN; AURAN'TINE* (-tin), Eng., Fr.; AURANTII'NA, &c., L. The bitter principle of the peel of oranges and lemons.

_Prep._ The exterior or yellow peel of the Seville orange (carefully separated from the white matter, and air-dried) is steeped in hot water, and the filtered liquor gently evaporated to dryness.

_Prop._, _&c._ It possesses the bitter properties of the peel without any of its glutinosity or fragrance, and is said to agree better with delicate stomachs. It may be taken in water either with or without the addition of a little sugar or capillaire, or dissolved in wine.

=AU"RIC= (aw'- or awr'-). _Syn._ AURI'CUS, L. Of or relating to gold, or containing it, or formed from it.

=AURIF'EROUS.= _Syn._ AU"RIFER, AURIF'ERUS, L.; AURIFeRE, Fr.; GOLDHALTIG, Ger. In, _mineralogy_, that yields or contains gold; as auriferous sand, a. quartz, &c.

=AURIPIGMEN'TUM.= [L.] Literally, paint of gold; appr., native orpiment.

See a.r.s.eNIC.

=AURO-CHLO"RIDES= (klore'-idz). Compounds of terchloride of gold with chlorides of other bases. They may be prepared by mixing the terchloride of gold with the chloride of the base, in atomic proportions, and setting aside the solution to crystallise.

_Prop._, _&c._ Most of the auro-chlorides crystallise in prisms, dissolve in both alcohol and water, have an orange or yellow colour, and are decomposed at a red heat.

=AURO-CY'ANIDES= (idz). In _chemistry_, compounds of cyanide of gold with cyanides of other bases. They may be formed in a similar manner to the auro-chlorides. Auro-cyanide of pota.s.sium is much used in electro-gilding.

=AURORA BOREALIS.= This luminous phenomenon, which is occasionally seen in our own country on clear frosty nights, and much more frequently and vividly by the dwellers in more northern lat.i.tudes, has been supposed to have an electrical origin, and to be occasioned by the pa.s.sage of electricity through the rarefied strata of the upper regions of the atmosphere from the poles towards the equator. But physicists look upon this explanation as unsatisfactory, and inadequate to account for the effects produced. The hypothesis, however, seems to derive some support from the following fact:--

If one of Ga.s.siot's vacuum tubes be brought near to a powerful electrical machine, both while the machine is in motion and for some time after, flashes of light may be seen pa.s.sing from the wire at one end of the tube to the other extremity, which flashes bear a great resemblance to the auroral rays. The great doubt, however, is whether the conditions necessary to the production of the aurora are similar to those prevailing during this experiment, a doubt not lessened by the difficulty of satisfactorily accounting for the rarefied state of the atmosphere which is a.s.sumed to exist.

The forms which the aurora a.s.sumes are very varied and of great beauty; there appears, however, to be some general similarity in its aspect at the same locality. Its appearance is briefly as follows:--A dingy aspect in the heavens in a northernly direction is usually the precursor of the aurora; and this gradually becomes darker in colour, and a.s.sumes the form of a circular segment surrounded by a luminous arch, and resting at each end on the horizon. This dark segment presents the appearance of a thick cloud, and is frequently seen as such in the fading twilight, before the auroral light manifests itself. The density of this segment must, however, be very inconsiderable, as stars may sometimes be seen shining brightly through it.

This dark segment is bounded by a luminous arch of a blueish-white colour, which varies in breadth from 1 to 6 diameters of the moon, having the lower edge sharply defined, and the upper edge only when the breadth of the arch is small. This arch may be considered to be a part of a luminous ring, elevated at a considerable distance above the earth's surface and having its centre corresponding with some point near the north pole. The preceding description indicates the general features of the appearance of the aurora borealis; but several auroras have been described which presented striking peculiarities. Sometimes the phenomenon a.s.sumed the form of one or more curtains of light, depending from dingy clouds whose folds were agitated to and fro as if by the wind. Sometimes this curtain appeared to consist of separate ribbons of light, arranged side by side in groups of different lengths, and attaining their greatest brilliancy at the lower edges. In this country the aurora borealis seldom a.s.sumes the distinctness and brilliancy which characterise its appearance in northern lat.i.tudes, but the description thus given indicates the type to which such appearance of the meteor more or less approaches. During the winter that prevails in the northern hemispheres the inhabitants of the arctic zone are deprived for months together of the sun's light, and their long dreary night is relieved by the light emanating from this beautiful meteor, which shines with great frequency and brilliancy in those regions.

A remarkable connection has been observed between the aurora and the earth's magnetism, the magnetic needle showing great disturbance during a display of the aurora. The arches of the aurora most commonly traverse the sky at right angles to the magnetic meridian, though deviations from this direction are not rare. Sir J. Franklin found that the disturbance of the needle was not always proportionate to the agitation of the aurora, but was always greater when the quick motion and vivid light were observed to take place in a hazy atmosphere. The aurora is most frequent and vivid in high lat.i.tudes, towards either pole, but the meteor is not confined to these parts, as Dr Hooker states that one of the most brilliant displays he ever witnessed was under the tropical sky of India; and other observers have recorded instances of its appearance in the equatorial districts of the globe.

The att.i.tude of the aurora varies considerably; there appears to be little doubt, however, that it frequently occurs at small elevations. Both Franklin and Parry record instances where it appeared below the level of the clouds, which they describe as having been hidden behind the ma.s.ses of its light, and as reappearing when the meteor vanished. It would seem that there are two distinct kinds of aurora one dependent upon local causes, as in the cases last given, while in the other causes are probably cosmical, and the auroral effects are seen at very distant points of the earth's surface.

=AURORA POMADE.= For promoting the action of the skin. Cocoa b.u.t.ter with orris.

=AUTOG'ENOUS= (toj'-). _Syn._ AUTOGE"NEAL; AUTOG'ENUS (toj'). L.

Self-generating or affecting; acting without the aid of foreign matter. In _anatomy_, &c., developed from distinct and independent centres; as parts or processes. Among _metallists_, it denotes a method of joining metals by fusing the parts in contact, by means of a flame of hydrogen, or of a mixture of hydrogen and common air, without the intervention of a fusible alloy or solder. Lead, and even ordinary hard solders, are, however, sometimes so employed, and the name, though improperly, retained.

=AUTOMAT'IC.= _Syn._ AUTOMATI'CUS, AUTOM'ATUS, L.; AUTOMATIQUE, Fr.; AUTOMATISCHE, Ger. Self-acting or self-moving, or that seems to be so; mechanical; of or resembling an automaton. In _physiology_, involuntary, applied to functions which are performed without the operation of the will; as the movements in respiration, the contractions and dilations of the heart, the persistent contraction of the sphincters, &c. In _mechanics_, &c., moving and acting from concealed machinery; also, as applied to _machinery_, self-regulating and directing, within the limits prescribed by its author, though moved by external power. To the last cla.s.s belongs the self-acting machinery of our flax and cotton mills, our engineering establishments, &c.; in which the elemental powers are made to animate, as it were, millions of complex organs, infusing into forms of wood, iron, and bra.s.s, an agency resembling that of intelligent beings.

The manufactures in which such machinery is employed are termed the AUTOMATIC ARTS.

=AUTOPSY.= Literally, personal observation or examination; ocular view.

The term, however, is now applied, rather loosely, to a post-mortem investigation. A post-mortem may be performed with the object of endeavouring to ascertain the cause of death in a medico-legal inquiry, or in the furtherance of the study of pathology. It is also a preliminary to embalmment, and is sometimes had recourse to as a means of saving the child when a woman dies in full pregnancy.

In France no post-mortem examination is permitted to take place until at least 24 hours after death, this delay being enforced as a safeguard against the possibility of the body operated upon being still alive. In England no post-mortem can be made without the consent of the friends of the deceased, unless by warrant from a coroner; although in many public inst.i.tutions this consent is dispensed with. Whenever, however, a prisoner dies in gaol an inquest and post-mortem are held on the body.

An autopsy is to be discouraged in cases where a person has died from infectious disease; but should the law require it to be undertaken, disinfectants both during and after the operation should be liberally had recourse to.

=AUTUMNAL FEVER.= This term is chiefly employed by American medical writers to designate typhoid fever, because of its prevalence in the autumn.