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merely deposited from water, as to preserve its continuity unbroken ? 

 If this should be even imagined as possible, in the instance of a 

 single line can it be admitted that such a regular abstraction and 

 supply, imitating exactly those processes only known to be per- 

 formed by organized parts, could thus take place, through every 

 series of the vessels, and every fibre of the decayed wood ; and 

 thereby produce an appearance, not in the least differing, from that 

 of the original wood itself. But were even this to be claimed as 

 possible, and were it allowed that the form of the wood might be 

 thus preserved, and its structure imitated ; how should we, on this 

 hypothesis, account for the original colour of the wood being ex- 

 actly retained? Can it be supposed that the original molecules 

 being thus removed, that the added particles of earth, derived 

 from the surrounding mingled mass, should be so disposed, that 

 the arrangement, and blending, of the variously coloured particles 

 should yield an exact imitation of all the different hues, and of the 

 disposition of the characteristic shades of colour, of the original 

 wood. It indeed appears to be impossible, that the almost for- 

 tuitous disposition of the atoms, by which such a substance would 

 be formed, could perfect so exact a resemblance in the figure, struc- 

 ture, and colour of an organized body, that the eye, unaided by 

 the touch, should not be able to discover the difference. 



The theory of Dr. Hutton next demands examination. The im- 

 pregnation of silicious fossil wood, he supposes to have been effected 

 by injection with flint, in a state of simple fusion by fire. " With 

 whatever different substancrs," he says, " the woody body shall be 

 supposed to have been penetrated, in a state of solution by water, 

 the regular structure of the plant would still have remained, with its 

 vacuities, variously filled with the petrifying substances, separated 

 from the aqueous menstruum, and deposited In the vascular struc- 

 ture of the wood. There cannot be a doubt with regard to this pro- 

 position ; for, as it is, we frequently find parts of the consolidated 



