ORB, ORBIT. 



ORCIN. 



32 



embrace tnuch that is useful : " Keep the trunk of the body erect ; 

 let your hands be at liberty ; feel your subject, and the action will 

 come ; recollecting at the same time that the right hand is essentially 

 the instrument of action, and that the left should be used only as 

 subordinate to it." 



As gesture is used for the illustration and enforcement of language, 

 so it should be limited in its application to such words and passages as 

 admit of or require it. A judicious speaker will not only adapt the 

 general style and manner of his action to the subject, the place, and 

 the occasion, but even when he allows himself the greatest latitude, he 

 will reserve his gesture, or at least the force and ornament of it, for 

 those parts of has discourse for which he also reserves his boldest 

 thoughts and his most brilliant expressions. 



(On the subject of action very minute directions will be found in 

 Austin's Chironomia ; Chapman's Music of tht English, Language, 

 Walker's Elements of Elocution ; Richard Cull's Acoustics and Logic in 

 their Application to Reading aloud, 1855; and James Hunt's Manual of 

 tlie Philosophy of Voice and Speed', especially in Relation to the English 

 Language and the Art of Public Speaking, 1859.) 



ORB, ORBIT. The word ort/i signifies the circumference of a circle 

 or of any round body ; orbs among the ancient astronomers meant the 

 vast crystal spheres in which the heavenly bodies were supposed to be 

 placed, and with which they revolved ; hence orb came to be used for a 

 sphere, as when the sun is called the orb of day. The word orbit now 

 means the relative path [MOTION] in which a planet travels round the 

 sun, or a satellite round its primary. 



We should perhaps rather say that by the orbit of a planet, 

 technically speaking, is meant the approximate path, circular or 

 elliptic, in which the planet may for a time be supposed to move 

 without sensible error. Thus, when for some particular purpose, as the 

 explanation of the seasons, we say the earth moves round the sun in a 

 circle, we make an orbit which is exact enough for that purpose ; and 

 when, to explain the equation of time, we are obliged to have recourse 

 to a more exact supposition, that of an elliptic motion, we are still said 

 to apeak of an orbit of the earth. But if we were to speak of the 

 closely-folded interlacing spiral in which the centre of the earth 

 actually moves round the sun, usage (and nothing else) would require 

 us, if we would be understood, not to call this the orbit of the earth, 

 but its real path, or real orbit, or some such distinctive term ; for it is 

 generally understood that the word orbit applies at most to the ellipse, 

 which for a time does not differ sensibly from the real path. 

 Theoretically speaking, this ellipse only touches the real path in one 

 point ; and the ^ellipse which most exactly tends to coincidence with 

 the real path, consistently with satisfying other desirable conditions, is 

 called the instantaneous ellipse. [GRAVITATION.] 



The element* of the orbit are those quantities by which the position 

 and magnitude of the (pro tempore) orbit are fixed, such as the major 

 axis and eccentricity, which determine its magnitude ; the longitude of 

 the node and inclination of its plane to the ecliptic, which determine 

 the position of that plane in space ; and the longitude of the perihelion, 

 which determines the direction of the major axis. One more deter- 

 mining quantity is tacitly supplied in the condition that one focus of 

 the ellipse is always to be in the centre of the sun. The only remaining 

 element is the periodic time of the planet, or its time of revolution 

 round the sun ; this however is not a separate element for each planet, 

 but, all the other elements being given, is known for every planet 

 when it is known for any one. 



ORCEIN. [LICHENS, Colouring matters of; Oncm] 



ORCHARD. Apples, pears, plums, and cherries are the fruit* 

 principally cultivated in orchards. The term orchard is likewise used 

 tu signify enclosures in which filberts or walnuts are grown : the word 

 yard is commonly used for similar spaces appropriated to the produc- 

 tion of figs and grapes. 



Orchards of apples and pears are more numerous, because more pro- 

 ductive, on the old and new red-sandstone formations than on any 

 other strata ; a very large proportion of all the cider and perry that is 

 manufactured is grown upon these soils. The principal orchards of 

 England are in Devonshire, Somersetshire, Gloucestershire, Hereford- 

 shire, and Worcestershire; on the continent, in Normandy and in the 

 vale of Stuttgard ; and in America, in the New England states. 



For an orchard of apple-trees, a deep unctuous soil should be 

 selected, in a situation sheltered from the north and north-west winds, 

 and open to the south and south-east ; and a bank is preferable to a 

 low spot, for not only is the blossom more liable to be injured by 

 spring frosts where fogs and damp prevail, but the trees themselves 

 become mossy, and perish from excess of moisture. Dr. Lindley 

 Me to Orchard and Kitchen Garden,') recommends an early and 

 effectual ^preparation of the soil, and the early transplanting of the 

 trees. Young trees will require to be watered if a dry spring should 

 succeed the autumn of their planting, and their roots should be occa- 

 sionally dug round and manured. Pruning is advantageous to young 

 trees when skilfully performed, for it is desirable that branches should 

 'crowded together, especially in the centre of the tree : we are 

 f opinion that it is seldom beneficial to old trees, excepting for the 

 removal of misletoe ; and recommend that under no circumstances 

 should a primer be employed who amputates large limbs and leaves 

 wounds which injure the alburnum or rap-wood by exposing it to the 

 atmosphere, and produce canker in the stem or principal branches. It 



AKTg AND SCI. DIV. VOL. VI. 



may frequently be useful in an exposed situation to plant two or three 

 rows of pear-trees to shelter the apple-trees from the prevailing storms, 

 as pear trees are on the whole less liable to suffer from wind than then- 

 more brittle kindred. The trampling of heavy cattle is at all times 

 injurious to orchards. 



For pear-orchards a lighter soil is desirable than for apples;- the 

 same rules may be observed for their planting and preservation. 

 Washes for the destruction of the eggs of insects, and directions for 

 the preservation of orchard-trees from barking by hares, rabbits, and 

 sheep, are given in Lindley ; Forsyth ' On Fruit Trees ; ' and London's 

 ' Arboretum.' For further information see articles APPLE, CIDER, and 

 PEAK. 



The principal cherry-orchards in England are in Buckinghamshire 

 and Kent ; from the latter county a large supply is sent to the London 

 markets. In Alsace, Wurternberg, Berne, and Basle, " kirschwasser," 

 an ordinary spirit, is distilled from cherries. There are likewise 

 orchards of a small acid cherry called " marasca" in the neighbourhood 

 of Trieste, and also near Zara in Dalmatia, from which Maraschino is 

 derived : in the Bergstrasse, near Heidelberg, there are cherry-orchards 

 which furnish an early supply to the London market. The cherry and 

 plum require but little pruning. 



In all cases, as is judiciously pointed out by Mr. Macintosh (' Book 

 of the Garden,' vol. ii.) it is of great importance that good sorts should 

 be introduced into, and the worthless extirpated from, our orchards as 

 soon as possible. The importation of good foreign fruit has rendered 

 the continued growth of inferior sorts a practice that must certainly 

 result in loss. Much has been done in this direction by market 

 gardeners. 



For filbert and walnut orchards see FILBERT and WALNUT. 



ORCHESTRA (Gr. opxfl<rTpa, which contains the same element as 

 the verb ofxfiattu, " to dance "), that part of the Greek theatre in which 

 the chorus was situated where the dances were performed. [THEATIIE.] 

 With the moderns, the orchestra is the place in the theatre allotted to 

 the instrumental band, and that portion of a concert-room which is 

 assigned to the musical performers, both instrumental and vocal. We 

 not only apply the word to the place set apart for the musicians, but 

 often use it to designate the whole of them collectively ; in which case, 

 orchestra and band are treated as synonymous terms. 



Till the end of the 17th century or the beginning of the 18th, the 

 instrumental performers of our theatres were stationed in a box on the 

 side of the stage, and out of view of the greater portion of the spec- 

 tators. They were then few in number. But, however desirable in 

 some respects, it would be impossible so to dispose of the large bands 

 of the present day ; and all things considered, they could not be better 

 placed than where they now are just below the stage, so as not to 

 interrupt the sight, and between the singer and the audience, thus 

 enabling the former to have in view the conductor and leader a 

 matter of great importance in the musical drama, where all is sung by 

 memory. 



The orchestra of a concert-room should be so contrived that the 

 front, when no passage beneath it is required, is about five feet higher 

 than the level of the room, and it should rise rather steeply to the 

 back, the corners of which ought to be rounded off, in order that the 

 whole body of sound may be directly reflected. But the due appor- 

 tionment of the orchestra to the size and character of the room, and 

 the requirements of the immense masses of vocal and instrumental 

 performers now employed in the execution of oratorios, &c., is a matter 

 that demands great knowledge of the laws of sound and considerable 

 adaptive skill on the part of the architect. None of the great music 

 balls yet constructed in this country can be considered as perfectly 

 successful in this respect. 



ORCHIL. [LICHENS, Colouring matters of.] 



ORCIN (C 1 ,H,O. + 2Aq.) Alphaordn. It has already been stated 

 [LICHENS, cotmtriny mailers of] that this peculiar crystalline principle 

 exists to a small extent in the free state in many of the lichens. It is 

 largely produced, however, when lichens are exposed to the joint 

 influence of heat and alkalies, conditions that always exist in the 

 manufacture of archil, litmuf, cudbear and other colour derivatives of 

 the lichens. Under these circumstances, some acid substances that 

 occur naturally in the lichens are split up into secondary acids and 

 ore! H, the latter immediately undergoing further alteration by absorb- 

 ing oxygen and nitrogen, and becoming converted into a deep purple 

 or red-coloured body termed orcein. By skilful management the 

 operation may be arrested at any stage, various tints being thus 

 obtained, or orcin itself may be extracted. 



Stenhouse gives the following directions for isolating orcin : exhaust 

 the lichens with water containing lime, boil the strained liquor till it 

 is concentrated to about one-fourth its original bulk, separate lime by 

 a current of carbonic acid, filter, evaporate to a syrupy consistence, 

 treat with boiling absolute alcohol, and set aside to crystallise. The 

 orcin thus obtained is usually of a red colour, but may be perfectly 

 decolorised by two or three recrystallisations from ether. 



Pure orcin crystallises in colourless quadrangular prisms, and is 

 very soluble in water, alcohol, or ether. It is neutral to test paper, 

 has a mawkish sweet taste, loses its two equivalents of water when 

 moderately heated, or when exposed in vacuo, or even when crystallised 

 from anhydrous ether. It sublimes in needles on being slowly 

 heated in flat vessels ; is precipitated white by acetate of lead, and red 



