0f0XF0 e 8JD'SHI\E. 83 



to Egypt. Encdiu6 r thinks it a fort of moifture of the earth, fo 

 concreted, that like Chryilal it will not diflblve, but remains as 

 it were an indiffolubie Ice, whence the Germans took occafion to 

 call it Glacies Marine. But that learned and induftrious inveftiga- 

 tor of Nature, Georgia* Agricola, differs from them all, and makes 

 it a product of Lime-Jione and water, Gignitur (fays he) ex[axo 

 calcvs cum fauca aqua -permifto" ; and thus I find it to grow here 

 with us at Heddington, in a blue clay that lies over the Quarry, 

 whofe outermoft cruft is a hard Lime-ftone. 



10. The learned and ingenious Steno^ in his Prcdromut, thinks 

 Chryftalls and Selenites^s, and all other Bodies having a fmooth 

 furface to have been already hardened, when the matter of the 

 Earth, or Hones containing them, was yet a. fluid ; if fo, indeed 

 Agricola muft be out in his aim. But I cannot fee how our bed 

 of clay at Heddington, above the Quarry at fome places ten foot 

 thick, could have been a fluid within fome ages paft ; and yet of 

 the Selenites's of the Rkomboideal Figure, I find fome as fmall as a 

 Barley-corn., fome about thre? inches, and others again at leaft 

 half a foot long : fo that they feem rather to have fome fncceffion 

 of growth, and now to be in fieri ; than to have been all together 

 already hardened, when the clay that now contains them was but 

 a fluid. Befide, they then would have been found clofe together, 

 w r hereas we here meet them fome higher fome lower, and mifc'd 

 all together little and great ; and the very clay it felf,as 'tis broken 

 to pieces, feeming fomwhat inclinable to this fort of form. 



n. A third fort we have of them alfo found here at Hedding- 

 ton, in the very fame clay, as alfo at Cor nwell and Hanwell; with 

 two fides like the former, more deprefled then the other, in com- 

 pafs alfo hexangular (thethineft fides of them being divided by a 

 ridge) but in the form, not of a Rhomboid, but an inequilateral 

 parallelogram, as in 7^. 2. Fig.i. d*. Some of thefewefind 

 fingle, lying in any poiture, the biggeft fcarce an inch broad, or 

 above four inches long ; and others joined together in a certain 

 pofition, with their flatteft fides towards each other, and edges 

 downward, and their endsconftantly meeting in a center. The 

 Ingenious Sir Thomas Pennyfton has obferved,that at Cormvell they 

 generally lye in ternaries, but here at Heddington we find them 



t De Lap'tdiimft Gentmit, lit. \cef- $6- a De Natura Fojji/ium, lib. 5. w Prodromi prop. 1. obftr- 

 vat. i- There are fuch as thefe in Spain, Thuringia, and Cappadocia. Aldrovand. Itb./y.cap.^. 



L 2 often- 



