Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/784

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Vefttges of the utriculi and trachea or air-veiTels are yet re- maining;, and the feveral circles yet vifible,' which denoted the feveral years growth of the tree, none can deny fuch fubftances to be real Mile Wood. Hill's Hift. of Kofi", p. 639. Sec the article FoJJile Plants.

One of the moft fmgular inftances we have of the matter in which fojjile Wood may be preferred, k in Razynfki's hiftory of Poland ; he tells us, that when one of the kings of Poland went to vifit the great £il-t-rwnes in that kingdom, the fuper intend ant of the works (hewed him by way of cuvio- fity a vaff. mafs of the hardeft kind of the fait, in which was buried a piece of an arm of a tree ; the fait was broken with proper inftruments, and the Wood taken out ; it proved to be beech, with the texture fo plainly remaining that it was eafihy known, bat its- pores all filled with the matter of the fait in which it lay. It was of the thicknefs of the bone of a man's arm, and was as perfect and entire as when growing on the tree. It is the only inftance wo have of Wood preferved in this maimer ; and it would be well if we could by any means afcertain the time when it was depofited there. Razyn/ki's Hilt, of Poland.

Another remarkable inftance of the change wrought on Wood by lying under the earth, is that of its having been found as it were converted into iron ; that is, that the Wood has been as thoroughly impregnated with the particles of iron, as that which we ttfually call petrified IVood is "with the particles of ftone.

Mr. Licbknecht, profefibr of the mathematics at Giflen, was the firit who ever oblcrvcd this fmgular procefs of nature in the folTiIe world : Pie found in a mine, where' there" were many iron ores, a piece of n(i\-Wood y eaf:-ly difcoverable to be fuch by the courfe of its fibres ; the cortical part or bark of which was petrified or turned into (tone, as we ufually exprefs it in the common way, and its inner fubftance plain- ly turned into ablblute iron. This part of the fubftance was of the colour of iron, and took a like polifh ; it gave the fame found with a piece of fron when (truck, and bore the ftrokes of a hammer in the fame manner without fir caking.

Its fpecific gravity was alfo greater than that of any ore of iron. All thefe circumftanccs gave great probability of its being abfolute iron, but there were others whicii gave abfo- hite certainty of that. A piece of this and a piece of a rich iron ore were beaten to pieces feparately, and warned in feveral waters ; the iron ore was at firft evidently lighter, and fouled the water, but the iron in the Wood funk at once without throwing ofT any adventitious matter. After feveral warnings, however, the ore being cleared of its earth, &c. became heavier than the iron of the Wood. After roafting both in the fire, the iron in the Wood made a violent ebullition with oil of vitriol-, and fent up a thick va- pour; but the ore made very little ebullition, and fent up fcarce any vapour. This is the more wonderful, as the

■ finding; native iron even in the richeft pieces, is very un- common; nor does if. amoxrnt to certainty, from all thefe ejeperiments, that this fubftance was really perfect iron. The author obferves, that after melting with fait of tartar it was attracted by the magnet. Act. Erudit. Ann, 1710. See the article ^-Wood, infra.

Jamaica Wood. See the article Brazil, Cycl.

Petrified Wood, the opinions of the judicious part of the world have been very different in regard to the bodies pre- ferved in the cabinets of the curious, under the name of petrified IVood '; fome ahlrming thefe bodies to have been only pebbles, or flints accidentally formed in this (hape, and with veins rcfembling thofe of PVood; and others affirming, with equal warmth, that they have been really ^K-W, into which ftony matter has been brought by water. Many good arguments have been produced on both fides the queftion, but Mr. De la Hire has attempted to bring the difpute to a certain conclufion, by means of fome peculiarly happy fpecimens, which were of the palm-tree petrified, found in the deferts of Africa : thefe on comparing them with pieces of the palm-tree cut out of the recent Woody appeared to have every where the beautiful and regular veins of that Wood, and left no room to doubt, but that they certainly had been once the vegetating [food of that tree, though now converted into hard ftone ; the petrified pieces were perfect ftone, in all its qualities ; they had its hardnefs, its found when (truck upon, and were, as many other (tones are, opake in fome places, and tranfparent in others ; they were found on weighing them to be often of the fpecific gravity of recent pieces of the palm Wood, of the fame dimen- lions. One of thefe pieces was two foot long, and four or five inches broad ; this was part of the trunk of the tree (tripped of its bark ; in this all the fibres ran longitudinally, and wholly refembled thofe of the recent IVood; a' certain portion of them being forked at their ends, as they are in the IVood ; the fibres were all hollow, even in the (tone as in the IVood, and the interititial matter which had joined them together in the tree, appeared in the ftone to have formed a very ftrong fort of cement, approaching to flint. 'J 'he cavities in the once woody fibres appearing very large, Mr. De la Plire gave the following account of tharphKiionienon ;

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Heobfervcd, that long foft and many bodies, in drying, very ofteii had their internal parts all drawn toward the circum- ference, and conicquemly from the center; and that the confequence of this often was, that when the body was per- fectly dried, there appeared a more or lets regular variety in the middle, in form of an empty pipe or canal. The fmaller branches of many trees, he oblerves, ulualiy dry fo, and (bmetimes their larger arms and trunks ; and this elpe- cially when the IVood has been of a fofter nature ; this he imagines to have been the cafe in the trunk of this palm- tree, and that its feveral fibres, being all long and foft, might in drying have had their feveral parts recede in this man- ner from the center to the circumference, fo as to have at length formed every one of them a fort of long tube or pipe ; and that if this happened to them while woody, rt could not but be regularly preferved in them in their petrit fied ftate.

The other fpecimen was of the bottom of the trunk with a part of the roots : thrs was not only compofed like the former or longitudinal fibres perfectly analogous to thole* of the recent IVood, but from its under part there grew fe- veral roots of the thicknefs of a finger, and three inches or more in length : thel'e, which were covered with a thin bark, and had within them feveral fibres of an inconceivable fine- nets; compofed the body of each root, as the longitudinal fibres of larger diameters had the IVood of the trunk and within thefe there was contained a firm fubftance of the nature of the heart in the roots of trees, which had within it a yet different fubftance rcfembling the pith of the inner part of the fmall roots of this tree. This being all exactly the ftate of the fmall recent roots of the palm-tree, it does not feem at all to be fuppofed that nature, though ilie might have imitated barely the longitudinal fibres of a plain piece of IVood, accidentally in flone, fhould imitate all the feveral parts of which thele laft roots are compofed, all fo different in themfelves, and all difpofed in fuch 'exact and nice order. The very colours of the feveral parts of th-jfe roots were different in the ftone, fome kind of ftony matter having probably been fitter to enter the pores of the one part, and fome other kind of the other. The feveral fine fibres which compofe the body of each root beino- of a black gloffy ftone, of the nature of the common black = flint ; and the internal part or pith being fupplied by a white and more foft ftone. The pith having in drying obferved the fame law as was before mentioned, in regard to the fibres of the Wood, had become hollow like them in the drying, and corrfequently this white ftone appears hollow, and m form of a tube or pipe in many places. The companion of this petrifaction in this manner, with the recent IVood of the fame tree, left not the lealt room to doubt of its true origin.

Father Duchat alfo, an author of unqueftioned credit, af- firms from his own perfonal knowledge, that in the king- dom of Ava there is a river, whofe waters petrify recent IVood into flint ; and that he has often feen trees ftandino- in it, whofe bottom part fo far as covered with the water^ has been true flint, while all above was mere dry Wood, and fit for firing. Mem. Acad. Par. 1692. Shilling Wood. There are a great many things in which a piece of rotten Wood that fhines in the dark, agrees with a burning coal ; and there are alfo many things, in which they differ. They agree in thele particulars : 1. They are both of them proper and true luminaries, havino- lio-ht re- fiding in them, and are not like looking-glanes or white bodies, which are only luminous according to the quantity of light which falls upon them from other bodies, and which they reflect. 2. fioth mining Wood and burning coals re- quire the prefence of the air to keep them filming; and both require alio an air of a confiderable denlity ; and both having been deprived of their mining quality by the pump- ing out of tile air, will recover it again on the admittino- frelh air to them. 3. Both of them will eafily be quenched by putting them into water, and many other liquors. And 4. As a live coal will not be extinguished by any coldnefs of the air, neither will the pining Wood be deprived of its light on any additional coldnefs in that element. Philof. Tranf. N°. 32.

Thefe are the things in whicii they agree ; thofe they dif- fer in are the following • 1. A burning coal is eafily put out by compreffion, the treading on it and Squeezing it toaether readily divefting it of its light ; on the other hand, °com- preflion or crulhing of any kind feems not to have any effea upon the Jbin'mg Wood ; its bruifed parts Alining as brightly as its entire ones. If a piece of this Jbining Wood be fqueezed between two glafi'es, this experiment will be moft fairly tried ; and in this cafe, though the contexture of the whole be evidently broken, and the parts feparated, the light is as ftrong in thern as while the piece was entire. 2. A burning coal extinguifhed by the drawing out the air, will, after a few minutes be irrecoverable, on the admiflion of air in any manner; hut, on the contrary, the Jhining Wood, when thus extinguifhed and kept extinct for half an hour, will be immediately re-kindled on admitting the air to it. 3. A live eoal included in a fmall glai's, will c«n-

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