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Show NoTE XIX. FLINT. ~ . thus formed the common pavin_g fl:ones or . . or by partial folutiOn ; and have 11 d . to fl:rata amid the fihceous fand-attrmon e ravel, which is often ro e m bowlers; as well as th g a d in the fea. . beds which are either formed or col;: ll~ d matter as the Giant's Caufway and !imtlar ' h ~ of cryna tze y be a In what manner fnc a rna s . [, d . thout other volcanic appearances, rna f columns of bafaltes, could have been rat~ w•. another power in nature befides that~ matter not eafy to compreheRd; bu.~~ e;oem~s materials which have previoufly been ~n expanftle Yapour which ~ay have rat e. th aCl: of congelation. When the water 111 -igneous or aqueous folutton ; and that. lS v~illiams had by congelation thrown out. the the experiments above related of Major_ r f the hole of the bomb fix or etght {h II 1 mn of tee rOle rom r plugs from the bomb- e s, a co n . [, . b lk which cryfl:allize in coo mg, as . h high. Other bodies I fufpeCl: mcrea e _m u unds of melted brimfl:cne tnc es b ouring etght or ten po iron and type-metal. I remem er p c l"ttle time a part of the fluid beneath d ~ ized to fee aLter a I [, 1 into a pot to cool an was urpr it and radually rife into a promontory cvera break a hole in the congealed crufl: above k' f gf fion and of cryfl:allization and may b [; l has many mar s 0 u t . r & inches high; the a a tes k f li r marble petrofilex, Jatper, c. .thence, as well as many ot h er kinds of roc I- ' .a s o ppao w' er whof' e quantity h as not ye t {i d b h wer of conge atton, a d d have been rai e y t e po d ·ve fal than that of vapours expan e been afcertam. ed, an d per ha p s greater an mo. re um t r f mountains of gram.t e t. ttr e If' as • 1 · 1 s rife fometlmes ou 0 {i(t by heat. Thefe bafa uc co urn~ V 1 LXXX ) and as they feem to con 1 mentioned by Dr. Beddoes, (Phtl. Tranfaet. ho .. ..t {rll g.reater reafon to believe them . I completely fufed, t ere ts 1 XXIV of fimilar matena s more . fl: n· . of the mafs. See note ~ .to have been elevated in the coohng or cry a tzauon 49 NOTE XX.-CLAY. Hmre du flile Clays i1z wide expanjio11 jpread} Soft as the Cyg"~tet' s down~ their }now-white bed. CANTO II. I. 277· THE philofophers, who have attended to the formation of the earth, have ac. knowledged two great agents in producing the various changes which the terraqueous globe has undergone, and thefe are water and fire. Some of them have perhaps afcribed too much to one of thefe great agents of nature, and feme to the other. They have .gener:illy agreed that the firatification of materials could only be produced from fediments or precipitations, which were previoufly mixed or diffolved in the fea; and that what~ ·ever effects were produced by fire were performed afterwards. There is however gr~at difficulty in accounting for the univerfal fl:ratification of the fulid globe of the earth in this manner, fince many of the materials, which appear in. firata, . could not have been f11fpcnded in water; as the nodules of flint in chalk-beds, .the extenfi ve beds of fh ells, and lallly the llrata of coal, clay, fand, and iron-ore, which in moft coal-countries lie from fi'Ye to feven times alternately £l:ratified over each other, and none of them are foluble in water. Add to this if a folution of them or a mi xture of them in water could be fuppofed, the caufe of that folution mufl: ceafe before a prec ipi tati on could commence. .1. The great maffes of lava, under the various names of granite, porphyry, toadllone, moor-llone., rag, and nate, which conftitute the old world, may have acquired the old fl ratification, which fome of them appear to poffefs, by their having been formed by fucceilive eruptions of a flu id mafs, which at different periods of ancient time arofe from volcanic !hafts and covered each other, the furface of the interior mafs of lava would cool and become folid before the fuperincumbent fl:ratum was poured over it: t0 the fame caufe may be afcri bed thei r different compofitions and tex tures, which are fca n.:ely the fame in any two parts of the world. 2. The fhati fica ti0ns of the great maffes of lime-fl:one, whtch were produced from fea-fht:lls, fccm to have been formed by the different times at which the innumer~ble fh ells were produced and depofitcd. A colony of echini, or madrepores, or cornua ammon is, li ved and perifh ed in one period of time; in another a new colony of either .fi milar or diffe rent {hells lived and died over the former ones, producing a firatum of more recent 1hells over a fl: ratum of others which had begun to petrify or to become n1:1rble ; and thus from unknown depths to \vhat are now the fummits of mountains the limc-ftone is difpofcd in firata of \·aryjng folidi ty and colour. Thefc have afterw:~rds {ll1dergone variety of changes by their folut ion aud depofition from the water in which they were i m m ~:r!l.d, or from havi ng been cxpofed to great heat under great prciliJre, a~cordin g to the ingeniou theory of Dr. liuttou. EJinb. Tranfaet. Vol. J. .See ~o t e X V L G • |
