X54 Account of the Peat Mojja and She!! Mar! May 



The fliells compofing the marl, many of which are quite entire, 

 are of the water fnail or cochlea kind, [Helix Pi/frij^ Lin.) 



The great value of luch a bed of marl ought to be a powerful 

 Inducement to every one that pofTelTes any mofs grounds lo fearch 

 them carefully, and particularly in their deepeft receflcs, and even 

 beneath their immediate fubibil, for this important article of ma- 

 nure, 



Mr Dempfier hatli foKl from the bottom of this mofs, marl to 

 the extent of upwards of 1 2, occl. Sterling, or at the rate of 

 loocl. per iinnumj ever fmce the period it was drained, which is 

 about twelve years ago: and the quantity that remains is yet 

 very great. 



The immcnrity of time that I apprehend it would take to 

 form fo valt a coileciion of luch minute {hell animals is beyond 

 our conception, if we might be permitted to judge from natural 

 cau'es and clredls. 



This valley, when it ceafed to be a lake, from circumflances 

 now to us incomprehenfible, unlcfs the vaft accumulation of 

 fhells can be deemed a fuihcient caufe, feems to have acquired 

 a furface fit for the produflion of trees: for all the under layers 

 cf the mofs, next to the marl, are compofed of roots, Hems and 

 branches of alder, birch, hazel (with the nuts of this lall tree 

 externally entire), and fome oaks of confiderable fize. 



It hath been fuppofed poihble that this coUeftion of trees may 

 have been floated from the higher grounds ; but it is not pro- 

 bable that all thefe trees could be depofited in this manner, as 

 there is.no appearance of any rivulet having ever run into the 

 valley. It may rather be prefumed that the fediment of water, 

 percolating from the adjacent grounds, may have formed above 

 the marl a foil proper for the growth of trees. 



From a wood the valley mult ha\re been transformed into a 

 peat bog or mofs, probably by a Ilagnation of water which would 

 naturally occafion the de(lru6lion of the trees and the growth of 

 aquatic plants, which, in fuch fituations, accumulate and ne- 

 ver fall into a Hate of total decompofition. The peat matter is 

 found about fix feet thick above the marl, and at the time of 

 the drainage its fur lace v^^as covered over with heath. 



By drainage and Mie confcquent alteration of the nature of the 

 foil, the heath has been entirely obliterated, and the mofs, even 

 at the furface, formed into a fine light mould, and covered with 

 grafs, coarfe Indeed in general ; but where It hath been gra- 

 velled for a road, it is not unworthy of notice, that it is fwarded 

 at the fides with the -^finefl paHure grafles and clovers: Couch 

 i]jrafs or twitch (triiicum repensj was there alfo particularly ob- 

 fervable. 



This mofs hat!* bc:en drained by one deep cut through the 



middle 



