« ForrigeFortsett »
accompanied with quartz, mica, &c. and ists under a variety of forms. It is gene. is also found in great quantities in alluvial rally found crystallized. The sulphuret land. The greater part of the English, of tin is of a pale, or dark grey colour, much of the Spanish, and the greater pro- and, when pure, has some resemblance portion of that from India, occurs in that to an ore of silver. To obtain the metal situation.
from its ores, they are first roasted, and Tin is not found in many countries; then treated with a flux, to reduce the but where it exists at all, it is in very metal. After the ore is roasted, it fuses considerable quantities. In Europe there readily with three times its weight of are only three tin districts: the first is black Aux, and a little decrepitated mu. in Saxony and Bohemia ; the second in riate of sola. In the humid way, native Cornwall; and the third is that of Galli- tin may be dissolved in nitric acid, which cia, on the borders of Portugal. It is readily oxidates, and reduces it to the found in many parts of Asia, and in South state of white powder, which is an oxide America. It is worked as an ore of tin, of tin ; and if it contain iron and copper, and from it all the tin of commerce is ob- these two metals remain in the solution. tained. Its name is derived from the Tin is of a white colour, nearly as brilquantity of tin which it affords, and its liant as silver. The specific gravity of unmetallic aspect.
tin is nearly 7.3. It is one of the softest 3. Cornish tin-ore, or wood-tin; which, of the metals. It is extremely flexible, like the last, is very heavy ; before the and so malleable, that it can be easily blow-pipe it is infusible; it consists of beaten out in plates to gobo part of an about 63 parts of tin, with iron and inch, which is the thickness of tinfoil. It arsenic. It has hitherto been found only has little elasticity or tenacity. A wire in Cornwall, and there in alluvial land. It
of this metal, about one-tenth of an inch is very like brown hematite, from which
in diameter, supports a weight of about it is distinguished by its colour, its rolled thirty pounds, without breaking Tin is pieces, greater hardness, and higher spe. susceptible of very considerable expancific gravity. We now turn to tin, in a sion, by means of caloric, and on this acchemical view.
count it has been proposed to employ it Tin is a metal of a silver white colour, as a pyrometer. Tin is one of the most very ductile and malleable, gives out, fusible of the metals, and melts at the while bending, a crackling noise, is fusi. temperature of 442°; but it requires a ble at a heat much less than that of igni- very high temperature to raise it in va. tion, is soluble in muriatic acid, and, by pour. If it be allowed to cool slowly, dilute nitric acid, is rapidly converted in- and when the surface becomes solid by to a white oxide. Tin has been known pouring out part of the liquid metal, from the earliest ages. It was much em- crystals are formed, composed of a great ployed by the Egyptians in the arts and number of small needles. Tin is a good by the Greeks as an alloy with other me. conductor of electricity. It possesses a tals. Pliny speaks of it under the name peculiar, odour, which is communicated to of white lead, as a metal well known in the hands by friction. It has also a perthe arts, and even applied in the fabrica. ceptible taste. When this metal tion of many ornaments of luxury. He posed to the air, it is soon tarnished, and ascribes to the Gauls the invention of the assumes a greyish-white colour; but it art of tinning, or covering other metals undergoes no further change. When it with a thin coat of tin. The alchemists is melted in an open vessel, it is soon cowere much employed in their researches vered with a greyish pellicle, which is concerning tin, and gave it the name of the commencement of the oxydation of Jupiter, from which the salts, or prepara- the metal. When this pellicle is removtions of tin, were called jovial. Since ed, another forms, and so on successively, their time, the nature and properties of till the whole is oxydated. By continuing tin have been particularly investigated by the heat, and by agitation, the process many chemists, and it has proved the goes on more rapidly, and the metal is subject of some important discoveries in converted into a whitish powder. This chemical science. Tin exists in nature oxide contains about twenty parts of oxy. in three different states. 1. It is found gen in 100 of the metal. With the addinative ; 2. In the state of oxide; and, 3. tion of lead, to promote the oxyclation, In that of sulphurated oxide. Native tin this oxide is the putty of tin. It contains is in brilliant plates, or regularly crystals about two parts of oxide of lead, and one lized. The native oxide of tin, which is part of oxide of tin. But when tin is the most common ore of this metal, ex. strongly bcated, it is converted into a fine
white oxide, which, during the process, black mass, which is sulphuret of tin. This gives out a vivid white flame. This oxide compound, which is a sulphurated oxide is condensed in the cold, and crystallizes of tin, was formerly distinguished by the in shinning, transparent needles.
name of aurum, musivum, musicum, or Tin combines with two proportions of mosaicum. The component parts of this oxygen, thus forming two oxides. The sulphurated oxide of tin are, yellow oxide, which has the smaller pro
Oxide of tin portion of oxygen, may be prepared by dissolving tin in nitric acid diluted with
Sulpbur water, without the aid of heat. By pre
100 cipitating the oxide with pure potash, it is obtained in the form of a yellowish powder. Its component parts are,
Tin enters into combination with many
of the metals, and forms alloys with Oxygen
them, some of which are of great importTin.
ance. It also combines with acids, and
forms salts. 100
Of the alloys, the most important is that of tin and copper, with some other addi
tions, which forms bronze,bell-metal, spe. By dissolving tin in concentrated nitric culum metal, &c. The alloy of tin and acid, with the assistance of heat, the lead, in equal parts, forms plumbers' sol. whole is converted with effervescence der. The alloy of tin, lead, and bismuth, into a white powder, which falls to the in the proportions of 3, 5, and 8, forms a bottom of the vessel. The compotent compound that melts in a heat somewhat parts of this oxide are 28 oxygen, and 72 less than that of boiling water. The amal. of tin.
gam of mercury with tin is used in silver. Phosphorus combines very readily with ing of mirrors. Pewter is an alloy of tin, by projecting bits of phosphorus on tin and lead, which was formerly very melted tin in a crucible. A phosphuret of much used, more so than any other me. tin is thus obtained, which crystallizes on tallic alloy, being the common material cooling. This compound is of a silvery for plates, dishes, and other domestic white colour, may be cut with a knife, utensils. Its use now is almost universal. and extended under the hammer, but ly superseded by pottery, which is lightsoon separates into plates. Sulphur com er, more readily kept clean, and much bines very readily with tin, by adding cheaper, though certainly less durable, the sulphur to the metal while in a state on account of the brittleness of the latter. of fusion. This compound forms a grey. The name of pewter has been given to ish or bluish matter, which has a metallic any malleable white alloy, into which tin lustre, a lamellated structure, and crys- largely enters; and its composition is so tallizes in cubes, or in octahedrons. It is various, that hardly any two manufacturdecomposed by acids with effervescence. ers employ precisely the same ingreThe component parts are, according to dients, and the same proportions. The Bergman,
finest kind of pewter contains no lead Tin
whatever, but consists of tin with a small Sulphur.
alloy of antimony, and sometimes a little
copper, and in all the superior kinds of 100
pewter, the tin forms by far the greater part of the mixture. Pewter may be used
for vessels containing wine, and even vi. If equal parts of oxide of tin and sul. negar, provided there be from 80 to 82 pbur be fused together in a retort, sul parts of tin in the alloy, without the phurous acid, and some sulphur, are dis- smallest danger; hence its use as a mea. engaged, and there remains in the vessel The specific gravity of a mixture a compound of a brilliant, golden colour. of tin and lead is less than the mean spe. It crystallizes in six-sided plates. It is not cific gravity of the two metals separateacted on by the acids. When it is strongly ly. heated it gives out sulphurous acid and Tin is much used, particularly in the sulphur, and there remains behind a state of very thin leaves: it is then called
tin-foil. This is made from the finest tin, are about twenty-seven species, in two first cast into an ingot, then laminated to divisions: A. jaw vaulted ; lip membranaa certain extent, and afterwards beat out
ceous, emarginate. B. jaw rounded; lip with a hammer. Tin is used for tinning horny, three-toothed. copper, iron, &c. and the salts of tin are TIPULA, in natural history, crane-fly, employed in dying.
a genus of insects of the order Diptera. Tin plate, tinning. Tin combines with Mouth with a very short membranceous iron, and adheres strongly to its surface, proboscis, the back grooved and receiv. forming a thin covering. This is one of ing a bristle; two feelers, incurved, filithe most useful combinations of tin, for it form, and longer than the head ; the an. renders the iron fit for a great many valu. tennæ are mostly filiform. There are nearable purposes, for wbicli, otherwise, only one hundred and fifty species, in two account of its strong tendency to oxida sections, distinguished by their wings. tion, or rusting, it would be totally inap The insects in the division A have their plicable. This is well known by the name wings expanded; those in B have them of tin-plate, or white iron. The process incumbent. of tinning iron is the following : the plates Most of the insects of this genus are of iron being reduced to the proper thick. very like the gnat; they feed on various ness, are cleaned by means of a weak substances: the larvæ are without feet, acid. For this purpose the surface is soft, and cylindrical, with a truncate first cleaned with sand, to remove any toothed head, and feed on the roots of rust that may have formed. They are plants: the pupa is cylindrical, two-hornthen immersed in water, acidulated with ed before, and toothed behind. The larga small quantity of sulphuric acid, in which est of the European tipulæ is T. rivosa ; they are kept for twenty-four hours, and it is found frequently an inch and half in occasionally agitated. They are then body, and is distinguished by the colour well rubbed with cloths, that the surface of its wings, which are transparent, with may be perfectly clean. The tin is fused large dusky undulations, intermixed with in a pot, the surface of which is covered white towards the rib, or upper edge. with an oily or resinous matter, to pre This insect proceeds from a greyish larvent its oxidation.
found beneath the roots of grass in The plates of iron are then immersed meadows, gardens, &c. and in the months in the melted tin, and are either moved of July and August it changes into a about in the liquid metal, or are dipped lengthened chrysalis, out of which, in several different times They are then September, proceeds the complete anitaken out, and rubbed with saw-dust or mal. This is known by the title of longbran, to remove the impurities from the legs, and is frequently seen in houses surface.
during autumaal evenings, when, if it be TINCTURE, is commonly understood possible, it will destroy itself by flying to be a coloured infusion of any substance into the flame of a lighted candle. This in alcohol. It is a preparation much em propensity is common to many insects. ployed in PHARMACY, with many articles T. tritici of Europe is a very minute inof the MATERIA medica (which see), par sect. The antennæ are moniliform, longticularly vegetable
barks, aromatics of all er than the thorax ; legs very long. The kinds, and many of the resins and gum larva is found in the ears of wheat, to resins, which yield to alcohol, by infusion, which it is very injurious. that part of their substance in which most The Hessian fly belongs to this Linof the medicinal virtue resides.
næan genus: it has been described by T. TINCTURE, in heraldry, the hue or co Say, in the Journal of the Academy of lour of any thing in coat armour, under Natural Sciences, under the name of which denomination may also be includCecidomyia destructor. ed the two metals, or and argent, because TITANIUM, is a metal of a copper they are often represented by yellow and red colour, very difficult of fusion, soluwhite.
ble in muriatic acid, from which it may TIPHIA, in natural history, a genus be precipitated by a tincture of galls. of insects of the order Hymenoptera. This meial was discovered in 1793, by Mouth with a membranaceous rounded Klaproth. He obtained it from a mineral jaw, the mandible arched and acute; no called red schorl. In this mineral he tongue ; . four feelers, filiform, unequal, found the oxide of a metal different from and inserted in the middle of the lip; any other then known. To this, from antennæ filiform ; short, convolute ; sting Meriachan in Cornwall, where it was concealed within the abdomen. There found, he gave the name of menachanite,
but he had not succeeded in reducing it tion with the acids, and forms salts with to the metallic state. Klaproth afterwards them. analysed the menachanite, and found that If into a phial, filled with muriate of ti. it was precisely the same as the oxide of tanium, there is put a stick of tin, and the metal which he discovered in red the bottle enclosed with a stopper, a schorl. To this metal he gave the name of faint rose colour will soon be visible in titanium. This metal has been found only that part of the solution adjacent 10 the in the state of oxide. Red schorl consists tin, which by degrees will deepen to an entirely of this oxide. It has been found amethystine red, and extend through the in different countries, as in Spain, France, whole liquor. If zinc be substituted in. and Hungary. It is disseminated in the stead of tin, the solution will be first viofine specimens of rock-crystal which are let, and at length indigo blue. Attempts brought from Madagascar, crystallized in have been made to alloy titanium with long brilliant needles; the form of the other metals, but without success. The primitive crystal being a six-sided prism, white oxide, and also titanite, in subwith two-sided summits: that of the mole. stance, are said to afford, when mixed cule is a triangular prism, with right an with enamel flux, a straw yellow colour; gled isosceles bases. It is of a red co and we are informed, that it has been Tour of different shades. It is brittle, but used in the porcelain manufactury at Sé. the fragments are so hard as to scratch vres, as an ingredient in rich browns; but glass. The specific gravity is from 4.1 to the difficulty of obtaining a regular and 4.2. The other mineral to which Kla- uniform tint has at length occasioned it proth has given the name of titanite, is to be abandoned. composed of oxide of titanium, silica, TITHES, are the tenth part of the in. and lime, nearly in equal proportions. Its crease, yearly arising and renewing from specific gravity is 3.5. Titanium was ob. the profits of lands, the stock upon lands, tained by Vauquelin, by reducing the na. and the personal industry of the inhabittive red oxide. He mixed together 100 ants. And hence they are usually divid. parts of this oxide with 50 of calcined ed into three kinds; praedial, mixed and borax, and 50 of charcoal, formed into a personal. Prædial tithes, are such as paste with oil; and exposed the whole to arise merely and immediately from the the heat of a forge raised to 166° Wedg- ground, as grain of all sorts, hay, wood, wood. By this process he obtained a fruits, herbs. For a piece of land, or dark coloured agglutinated mass, having ground, being called in Latin prædium, a brilliant appearance on the surface. Ti- whether it be arable, meadow, or pasture, tanium obtained in this way is of a reddish the fruit or produce thereof is called præyellow colour, shining and brilliant on the dial, and consequently the tithe payable surface, and equally brilliant in some of for such annual produce is called a præits internal cavities.
dial tithe. Titanium seems to be one of the most Mixed tithes, are those which arise not infusible metals known. When the red immediately from the ground, but from oxide is exposed to heat in a crucible, it things immediately nourished from the loses its lustre. By the action of the blow, ground; as by means of goods depastured pipe it is deprived of its transparence, and thereupon, or otherwise nourished with becomes of a greyish-white colour. On the fruits thereof; as colts, calves, lambs, charcoal it becomes still more opaque, chickens, milk, cheese, eggs, and of a slate-grey. The artificial carbo Personal tithes, are such a's arise from nate of titanium, exposed to heat in a cru. the honest labour and industry of man, cible, loses 2 of its weight, becomes employing himself in some personal work, yellow, and as it cools resumes its white artifice, or negotiation; being the tenth colour. Titanium enters into combina part of the clear gain, after charges de. tion with phosphorus, and forms with it ducted. a phosphuret. This was prepared by M. Tithes, with respect to value, are divid. Chenevix, by exposing a mixture of phos- ed into great and small: great tithes, as phate of titanium, charcoal, and a little corn, hay, wood; small tithes, as the preborax, in a crucible, to a very strong
dial tithes of other kinds, together with heat. The phosphuret which he obtained
those that are mixed and personal was in the form of a metallic button, of a Tithes of common right belong to that pale white colour, brittle, and granular, church, within the precints of whose pa and infusible by the action of the blow- rish they arise. But one person may prepipe. This métal enters into combina- scribe to have tithes within the parish of VOL. XII.
another; and this is what is called a por ture of horses, or other beasts, which are tion of tithes.
used in husbandry in the parish in which No tithe is due de jure of the produce they are depastured; because the tithe of of a mine, or of a quarry ; because this is corn is by their labour increased. But if not a fruit of the earth, renewing an horses, or other beasts, are used in hus. nually, but is the substance of the earth, bandry out of the parish in which they deand has perhaps been so for a great num. pastured, an agistment tithe is due for ber of years. But in some places tithes them. No tithe is due for the pasture of are due, by custom, of the produce of milch cattle which are milked in the pamines.
rish in which they are depastured: beNo tithe is due of lime; the chalk of
cause the tithe is paid of the milk of such which this is made being part of the soil. cattle. Nor is tithe due for the pasture of Tithe is not due of bricks, which are a saddle-horse, which an occupier of land made from the earth itself. Nor of turf, keeps for himself or servants to ride up. nor of yravel; because both these are on. Cro. Jac. 430. But an occupier of part of the soil.
land is liable to an agistment tithe for all It has been held that no tithe is due of such cattle as he keeps for sale. Cro. salt, because this does not renew annually. Eliz. 446. Milk cattle, which are reservBut every one of these, and all things of ed for calving, shall pay no tithe for their the like kind, may by custom become pasture whilst they are dry; but if they tithable.
be afterwards sold, or milked in another If barren land is converted into tillage, parish, an agistment tithe is due for the no tithe shall be paid for the first seven time they were dry. No tithe is due from years; but if it be not barren in its own
an occupier of land for the pasture of nature, as if it be woodland grubbed and young cattle, reared to be used in hus. made fit for tillage, tithes shall be paid bandry, or for the pail. Cro. Eliz. 446. presently; for woodland is fertile, not But if such young beasts be sold before barren.
they come to such perfection as to be fit Glebe lands, in the hands of the par. for husbandry, or before they give milk, son, shall not pay tithe to the vicar; nor an agistment tithe must be paid for being in the hands of the vicar, shall they them. pay tithe to the parson: because the If cattle, which have neither been used church shall not pay tithes to the church. in husba dry, nor for the pail, are, after But if the parson let his rectory, reserv. having been kept some time, killed, to be ing the glebe lands, he shall pay the tithes spent in the family of the occupier of the thereof to the lessee.
land on which they are depastured, no No tithes are due for houses; for tithes tithe is due for their pasture. No tithe is are only due of such things as renew from due for the cattle, either of a stranger or year to year. But houses in London are, an occupier, which are depastured in by decree, which wasconfirmed by an act grounds that have in the same year paid of parliament, made liable to the payment tithe of hay But it is generally true, that of tithes. There is likewise, in most an an agistment tithe is generally due for cient cities and boroughs, a custom to pay depasturing any sort of cattle, the proper. tithes for houses; without which there ty of a stranger. Cro. Eliz. 276. would be no maintenance in many pa No agistment tithe is due for such rishes for the clergy.
beasts, either of a stranger or an occupier, As to mills, it is now settled by a de as are depastured on the head lands of cree of the House of Lords,lipon an appeal ploughed fields: provided these are not from a decree of the Court of Exchequer, wider than is sufficient to turn the plough that only personal tithes are due from the and horses upon. Nor is tithe due for occupier of a corn mill
And the occu
such cattle as are depastured upon land pier of a new erected mill is liable to that has the same year paid tithe of corn. tithes, although such mill is erected upon If land which has paid tithe of corn one and discharged of tithes. Cro. Jac. 429. year is left unsown the next year, no
Agistment, or the feeding of cattie, is agistment is due for such land : because, subject to tithe. In the strict sense of ihe by this lying fresh, the tithe of the next word, it means the depasturing of a beast crop of corn is increased. But if land, the property of a stranger; but this word which has paid tithe of corn in one year, is constantly used in the books for depas- is left unsown the next year, no agistturing the beast of an occupier of land, as ment is due for such land, but if suffered well as that of a stranger. An occupier of to lie fallow longer than by the course of land is not liable to pay tithe for the pas. husbandry is usual, an agistment tithe is