286 



upper marl four or five feet thick, resting upon the dark green, 

 which is here called blue marl, and from which it is occasionally- 

 separated by a crust of cemented ferruginous matter an inch or 

 two in thickness. Mr. White has applied the material of this 

 upper stratum to a portion of his soil without any apparent benefit 

 to the crops, and his sentiment is, that it is destitute of fertilizing 

 powers. In the pits farther up the creek, where a thin stratum 

 of it occurs, it is dug and use is made of it, though the farmers 

 prefer the marl from the darker bed below. 



In the banks nearest the town, we behold only the lower marl 

 penetrated in some places to the depth of fourteen feet, and resting 

 under the gravelly diluvium, from which it is parted by a thin 

 cemented ferruginous crust, a proof of the imperviousness of the 

 stratum, and the facility with which the water penetrates the 

 diluvium, and brings down the oxide of iron which it contains. 

 As the covering of diluvial sand and gravel increases in thickness 

 in receding from the creek, it is becoming a daily augmenting 

 obstacle to the uncovering of the marl, rendered more serious by 

 the copious ingress of water from the marl itself. I take this 

 place to recommend attention to the advantages to be derived 

 from the application of some simple machinery, for the purpose 

 of more effectually elevating the marl and draining the pit, that 

 it may not be necessary to abandon each excavation at the trivial 

 depth of ten or twelve feet, and to incur the labour of uncovering 

 fresh surfaces of the marl bed. 



Marl from the farm of Michael Nulls, three m,iles from, 

 Woodstoiun. 



Description. — Colour, dull green; the washed grains, very fine 

 and of a very rich sea-green colour. 



Composition. — In 100 parts: 



Greensand, - , . 83*5 

 Clay, - - - - 14-5 

 Quartzose sand, - - 2-00 



10000 



The proportion o^ potash, in this marl deduced from that of the 

 greensand, is 9-6 per cent. 



