384 PHILOSOPHICAL TRANSACTIONS. [aNNO I767. 



those bones have been deposited there since the flood, and have been covered by 

 an addition of earth, as has happened also to some of the trees and woods that 

 were cut down in this island by the Romans. And, as to the rest, it cannot be 

 supposed, but that on the first great eruption, which poured the waters of the 

 ocean upon the dry land, there must have been a violent agitation for some time, 

 by their flowing backward and forward ; during which interval, the bodies of 

 many terrestrial animals, floating on the water, would be washed to different 

 parts of the new-raised continent, and be left there as the water subsided. 



V. An Attempt to account for the Formation of Spars and Crystals. By Ed- 

 ward King, Esq. F. R. S. p. 58. 

 • In the first place, it is known, that the Bristol stones grow within the hollow 

 cavity of some other rough stone ; and that the substance of the external stone 

 is porous, and often so strongly impregnated with crystalline corpuscles, that 

 they glitter among the earthy particles, when held up to the light. 2. In the 

 next place, it is to be observed, that wherever there is a hollow cavity in these 

 kind of stones, the inside is almost always lined with such shining substances, 

 either in a perfect or imperfect state. 3, We find the Bristol stones appear in 

 several different states ; for in some places of the cavity, where the crystallization 

 is not completed, they are of a dusky red, without any transparency ; in others 

 they appear of a dirty yellow ; and in others white ; and at last transparent. 

 4. As to the spars and crystals formed even in flints, and other hard bodies ; they 

 are generally observed in such as have evidently been at one time or other in a 

 soft state, and lay in or near moist places strongly impregnated with saline par- 

 ticles ; or else they are found in bodies wherein some saline and moist substances 

 have formerly been inclosed, and prevented from evaporating ; of which kind are 

 the spars found in fossil shells, in which the bodies of the shell fish have perhaps 

 lain and perished. 5. We observe, not only in the small cavities of stones, but 

 also in large caverns, such as those in the Peak in Derbyshire, Okeyhole in So- 

 mersetshire, and the famous grotto in the Greek island of Antiparos, and in 

 short wherever moisture descends through the earth to a void space, and stops on 

 the inner surface, that it there forms crystals, or spars, or stony concretions of 

 some sort or other ; of which some are so very imperfect, as to have only the ap- 

 pearance of rude heaps of petrified matter, without any regular form, which 

 chiefly happens where there is much moisture, and where it descends, or soaks 

 through pores so large as to carry many earthy particles with it. 6. To all which 

 he adds, that Sir Isaac Newton has made it appear, that the transparency of bo- 

 dies is occasioned by the minuteness of their pores, and the opacity of them by 

 the largeness of the pores, in which the rays of light being reflected from side to 

 side are lost, and prevented from passing through; whence it is, that paper be- 



