i?i the Envh'ons of' Paris. 257 



niurices, solens, tellinae, turritellae, vertebrae of fish, vo- 

 lutes, &c. Below the above, three small beds oF plaster 

 and some strata oF marie occur, without shells ; and lower, 

 a bed ot" calcareous marie, in ilie midst of which is a plaster 

 or gypsum bed, which contains cerites of the genera petri- 

 colum and terebrale; many of which sea shells are per- 

 fectly similar to those in coarse limestone at Grignon, and 

 other places, not only in made? here, lying between beds 

 of gypsum, but in the gvpsum itselF, although several na- 

 turalists have {]ue3tioned the reality of such an occurrence. 

 The above particulars I have learnt, from a notice in Mr. 

 Nicholson's Journal of the present month, which contains 

 other interesting particulars. Should M. Desmarets and 

 Prevost have presented any memoir on the above subject, 

 you will not, I hope, fail to translate it at length, on its 

 reaching this country. 



In the respectable journal above mentioned, Mr. Richard 

 Winter has given an interesting account of the manufacture 

 o^ alum in ihe neighbourhood of Whitby, and of the strata 

 whence the raw material or alum -shale for making this 

 useful article is procured ; of which geological particulars I 

 beg to present a brief sketch, for the purpose of soliciting 

 further information, through the medium of your Magazine, 

 such that may enable us to fix the place of these strata in 

 the British series. 



Alum-shale, a blueish gray argillaceous schistus, occupies 

 the coast of Yorkshire for about ten miles southward, and 

 18 miles northward of the town of Whitby, and extends 

 inland a great distance ; cliffs of this shale appear on the 

 shore which are from 100 to 750 feet high, and on which 

 the sea is continuing to make its inroads. A ferruginous 

 sand-stone (perhaps the same with that of Woburn), iron- 

 stone, and shale, or clay ot its decomposition, covers the 

 alum-shale stratum, having an easy dip to the southwest. 

 T!)e sand-stone appears from 4 to 50 or more yards thick, 

 producmg ochrey springs at its bottom ; it hardens by ex- 

 posure in buildings : a thin bad scam of coal or jet, (pro- 

 bably bituminized wood,) seldom exceeding tuo inches in 

 thickness, is sometimes found under or in the lower part 

 of the sand-stone: the slines or length-way joints of the 

 strata of stone and shale range N. and S., and the end or 

 cross joints E. and VV. 



The alum shale contains several species of ammoniice, 

 abundance o\ belemnitce, hones of animals, iiautHi of two 

 or three species, shelU of various kinds, trochit(^^ and 

 veriebrce of fishes or animals. It likewise holds nodules of 



Vol. 35. No. 144. April 1810. R indurated 



