438 Proceedings of the British Association. 



Another specimen from the village of Wheldon, adjoining the York 

 and North Midland Railway, near Castleford, gave the following as its 

 principal ingredients, viz. — 



Carbonic Acid, 4600 



Lime 35-04 



Magnesia, 17-50 



Red Oxide Iron, 090 



Insoluble Matter, 0-50 



Loss, 006 



100 00 



This limestone appears then to consist of 62-32 per cent, carbonate 

 of lime, and 36-75 carbonate of magnesia, or approaching nearly to the 

 constitution of dolomite, containing 1 atom carbonate of lime and 1 

 carbonate of magnesia. From the above statement, it would appear 

 that this species of limestone is not well calculated for agricultural 

 purposes, except perhaps., under peculiar circumstances, and applied in 

 small quantities. 



The Upper Magnesian Limestone is in immediate succession to the 

 lower one, and directly beneath the new red sandstone. It is found in 

 considerable abundance at Knottingley, Brotherton, and, no doubt, in 

 other localities in this county. Its specific gravity is about 264. It is 

 of a greyish brown colour, much harder in texture than the preceding 

 variety. According to analysis, the following are its principal ingre- 

 dients, viz. — 



Carbonic Acid, 42-35 



Lime, 51*61 



Magnesia, . . .. .. .. .. .. .. a trace. 



lied Oxide Iron, 1-42 



Insoluble Matter 4-50 



Loss • .. 0-12 



100-00 



As this limestone appears to contain about 93-96 per cent, carbonate 

 of lime, it would seem to be tolerably well adapted for the purposes of 

 agriculture, as the very small proportion of magnesia that it appears to 

 contain, can scarcely be supposed to exert much deleterious influence. 



The Oolitic Limestone is the next in order to the magnesian, and is 

 found in considerable abundance in the neighbourhood of Malton. It 

 is of yellowish white colour, and appears to be composed of innumerable 

 small round particles, and hence it is commonly called roe-stone. The 



