107 



TOUJJXM. 



TINCA. 



10f8 



he say*, approaches Tillage* and plantations, constructing iU uet in 

 the Ledge* ; and he speaks of it as one of the social birds that delight 

 to dwell in the vicinity of cultivation. In large forests he did not 

 notice it He describes iU flight as low and interrupted, and adds 

 that wherever it resides it is a welcome neighbour, in consequence of 

 the peculiarity and pleasantness of its note, which consists of a slow 

 repetition of the five tones of the diatonic scale (o, D, K, r, a), which 

 it chants with perfect regularity, several times in succession, and at 

 small intervals of time. Dr. Hors&eld further remarked that the 

 sixth tone was sometimes added ; but as this required apparently an 

 extraordinary effort, it was by no means so agreeable to a musical 

 ear as the simple repetition of the five notes, which appeared to 

 be the natural compass of the bird's organs. (' Zoological Researches 

 in Java.') 



TIMALI'N.E, a sub-family of Birds belonging to the Turdida. 



[TlMAUA.] 



TIMOTHY GRASS, the common name for the Phlcum pratentt. 

 [PHLEGM.] 



TIN'. This metal is one of those which were earliest known, 

 though it occurs in comparatively few countries. The acquaintance 

 of the ancienU with this metal, though it does not occur in the native 

 state, is accounted for by the circumstances that the ore is found fre- 

 quently n<-ar the surface, and is easily reduced by charcoal and a 

 moderate degree of beat to the state of metal 



According to Berrelius Tin is found in England, Saxony, Bohemia, 

 Hungary, the Isle of Banca, the Peninsula of Malacca, in Chili, and 

 Mexico. Malacca furnishes the purest tin, and Cornwall the largest 

 quantity. 



Tin occurs in two states of combination, the peroxide and double 

 sulphuret of tin and copper : this last is rather a rare substance, and 

 it is from the former that the metal is almost entirely obtained. 



The Peroxide of Tin is found in Cornwall in two forms : 1. In 

 reins in primitive countries, where it is intimately mixed with several 

 other metals, as arsenic, copper, zinc, and tungsten : this is common 

 Twtonr. 2. In loose rounded masses, grains, or sand in alluvial soil, 

 in which state it is called Stream Tin. The former, when reduced to 

 the metallic state, yields Block-Tin; while the latter yields Grain-Tin, 

 which is the purer of the two. 



Oxide of Tin Tirutone occurs in attached and imbedded crystals, 

 and massive. Primary form n square prism, which is commonly 

 terminated by four-sided pyramids. Cleavage parallel to the lateral 

 planes and both diagonals. Fracture uneven or imperfectly conchoidal. 

 Hardness 6 to 7 : gives sparks with steel, and is brittle. Colour white, 

 yellow of various shades, red, brown, and black. Streak paler. Lustre 

 adamantine, vitreous. Transparent, translucent, opaque. Specific 

 gravity 6'96. Insoluble in acids. Before the blow-pipe, in powder 

 on charcoal, it is reduced to the metallic state. Fine crystals of this 

 substance occur, more especially in Cornwall and Saxony. 



The analysis of the Oxide of Tin of Cornwall by Klaproth gives- 

 Tin 77-50 



Oxygen 21-50 



Iron 0-25 



Silica 0*75 



100 



The Massive Varieties of Oxide of Tin are called Stream-Tin. What 

 is termed Wood-Tin is found in reniform and botryoidal masses, or 

 in wedge-shaped pieces, which have arisen from their partial destruc- 

 tion : the surfaces are generally water-worn. Wood-Tin exhibits 

 various shades of brown, which sometimes appear in concentric bauds, 

 giving it a ligneous appearance, whence its name. 



Stream-Tin has evidently been derived from the destruction of tin 

 TWOS or lodes, the lighter portions of stony matter having been 

 carried away by the water, which has rounded the fragments of 

 the ore. 



At Finbo in Sweden Oxide of Tin has been met with containing 

 newly 2*5 per cent, of Oxide of Columbium. 



Tin Pyrittt StUphuret of Tin, a double Sulphuret of Tin and Copper 

 is a rare substance, having been found only in Cornwall at Huel 

 Rock, in the parish of Si. Agnes. 



It occurs crystallised and massive. Primary form of the crystal a 

 cube. Cleavage parallel to the faces of the primary form. Fracture 

 uneven, with a metallic lustre. Hardness: readily scratched and 

 reduced to powder ; brittle. Colour stel-gray, mixed with yellow. 

 Specific gravity 4-36. 



Massive Variety- Fracture granular and uneven, with a metallic 

 lustre. Hardness 4. Brittle. Opaque. Specific gravity 4-35 to 470. 



The following analysis by Klaproth gives- 

 Tin 34 



Copper 30 



Iron . . 2 



Sulphur 26 



TIN PYKITES. [Tw.1 



TINAGTUK. [MKRULIBJL] 



TI'NAMOU, a genus of Birds belonging to the family Tcfraonidv. 



T. Tatavpa, is a native of South America. 



Tinamtu Tataupa, Tar. (Swainson.) 



Mr. Darwin, in his graphic description of the country around 

 Maldonado, gives the following account of this bird : " The country 

 wore the same aspect, till at last the fine green turf became more 

 wearisome than a dusty turnpike-road. We everywhere saw great 

 numbers of partridges (Tinamtu rvfetceni). These birds do not go in 

 coveys, nor do they conceal themselves like the English kind. It 

 appears a very silly bird. A man on horseback, by riding round and 

 round in a circle, or rather in a spire, so as to approach closer each 

 time, may knock on the head as many as he pleases. The more 

 common method is to catch them with a running noose or little lazo, 

 made of the stem of an ostrich's feather, fastened to the end of a 

 long stick. A boy on a quiet old horse will frequently thus catch 

 30 or 40 in a day. The flesh of this bird, when cooked, is delicately 

 white." (' Journal of Researches in the Countries visited by H. M. S. 

 Beagle.') 



TINCA, a genus of Fishes founded by C'uvier, and which has for 

 type the Common Tench (Cyprinia Tinea, Linn.). 



T. rulgaru, Cuv., the Tench, belongs to the Carp family (Cyprinidct), 

 and is separated gcnerically on account of the small size of the scales 

 with which the body is covered, combined with the small antero- 

 posterior extent of the dorsal and anal fins, both of which are destitute 

 of the anterior bony spine or any such as are observable in some 

 allied fishes as in the dorsal fin of the Barbel for instance. The 

 barbules to the mouth are very small. 



The Tench, observes Mr. Yarrell, inhabits most of the lakes of the 

 European continent In this country, though frequent in ornamental 

 water and ponds, it is but sparingly found in the generality of our 

 rivers. There is some doubt whether, like the carp, its origin be not 

 foreign, and whether those rivers that can now boast of it are not 

 indebted for it to the accidental escape of fish from the preserved 

 waters of neighbouring gentlemen. The rivers it is mostly in are 

 those which are slow and deep, and in such situations it does not 

 appear to be so prolific as in ponds. Cuvier observes that the tench 

 inhabits by preference stagnant waters. This is in accordance with 

 the observations of Mr. Yarrell, and rivers being an unnatural habitat 

 for the fish, will account for their being less prolific in such situations. 



It is very tenacious of life. " A piece of water which had been 

 ordered to be filled up, and into which wood and rubbish hod been 

 thrown for years, was directed to be cleared out. Persons were 

 accordingly employed; and, almost choked up by weeds and mud, 

 so little water remained, that no person expected to see any fish, 

 excepting a few eels, yot nearly 200 braco of tench of all sizes, and 

 as many perch, were found. After the pond was thought to be quit; 

 free, under some roots there seemed- to bo an animal which was con- 

 jectured to be an otter; the place was surrounded, and on opening 

 an entrance among the roots, a tench was found of most singular 

 form, having literally assumed the shape of the hole, in which he had 

 of course for many years been confined. His length from eye to fork 

 was 33 inches; his circumference, almost to the tail, was 27 inches; 

 his weight 1 1 Ibs. !' J ounces ; the colour was also singular, his belly 

 being that of a char, or vermilion. This extraordinary fish, after 

 having been inspected by many gentlemen, was carefully put into a 

 pond, and at the time the account was written, twelve months after- 

 wards, was alive nnd well." (Ynrrell.) 



Experiments have shown that a tench is able to breathe when the 

 quantity of oxygen is reduced to a five-thousandth part of the bulk 

 of the water : ordinary river water generally containing one per cent, 

 of oxygen. 



The general colour of the tench is greenish-brown, or olive having 

 a golden hue, which latter tint is most conspicuous on the under parts 

 of the fish. From the carp it is readily distinguished by the small 



