THE SOIL. — ^ITS FORMATION AND COMPOSITION. () 1 



1 32. WniTE LIM ESTONE. The rocks known to the farmers 

 in the northof Ir^iodby the name of white limestone^ though 

 of great agricultural value as a source of manui-e, do not to 

 any great extent dkectly contribute to the production of soils. 

 These rocks extend over the greater part of Antrim and over 

 parts of Down and Deny, and are regar^fid-iiy_£eologists_as 

 i^enticalwitjL-lIie._beds^ of .cha.lk which are so extensively 

 developeilm England, and merely altered in hardness by 

 the action ofjbhe. yolcanicLj*pcks. Being, however, covered 

 over witFTEe immense mass of Tasalt upon which the soils in 

 Antrun chiefly rest, the limestone is only occasionally visible. 

 It may be traced from the neighbourhood of Moira in Down 

 to the banks of Lough Foyle, and is observed making its ap- 

 pearance beneath the basalt at various points along the north- ( 

 east coast The white limestone belongs to what is termed ^ 

 the chalk formation^ which consists of a group of calcareous 

 rocks, and beds of sand, clay, and marl. Some of the beds 

 of the group contain a lai'ge quantity of fossil shells and 

 other "organic remains," and considerable attention has 

 lately been directed, both in this country and in England, to 

 the deposits of green-sand found immediately below the white 

 limestone (chalk), by the discovery that these beds contained 



Ballymena Eailway and of a subsoil in the neighbourhood of Larne 

 examined in ray laboratory. The subsoil was taken from a field 

 belonging to Dr. Kirkpatrick, on which the oat crop had several years 

 failed after exhibiting a most promising appearance. 



Basalt. Ked ochre. 



Silica . . . .53-70 26-00 



Alumina . . . 2541 26-93 



Lime .... 4.55 trace. 



Magnesia ... 1-37 73 



Oxide of Iron . . . 8-95 Peroxide 35-67 

 Sulphuret of Iron . . traces. 

 Water .... 4-30 10-33 in 100 parts. 



Subsoil from near Larne, Co.' Antrim. 



Sand and Siliceous matter . . . 58-00 



Peroxide of iron , . . . 12-60 



Alumina 12*00 



Carbonate of lime . . . . 0-40 



Magnesia 0-58 



Sulphuric Acid and traces of Alkalies . 0-20 



Organic matters 10-06 



Water 6-15 



99.98 

 H 



