Proceedings of the British Association, 437 



An attempt to establish a new atomic theory, involving two principles 

 — first, that every atom of matter consists of an indefinitely great sphere 

 of force, varying inversely as the squares of the distance from the centre ; 

 second, that atoms are of different sorts, when their absolute force or 

 spheres of repulsion are unequal. It is imagined, by the author, that 

 there are four distinct classes of atoms, viz. tenacious, electric, etherial, 

 and microgenal atoms. 



Saturday. 

 1 On the Limestones of Yorkshire.' — These limestones may be com- 

 prised under the four following classes, viz. — 



1. The Mountain Limestone. 



2. The Magnesian Limestone, including both the upper and lower beds. 



3. The Oolitic Limestone. 



4. The Chalk. 



The Mountain Limestone is developed, to a great extent, in the dis- 

 trict of Craven and in other parts of the north and north-west portions 

 of the county. It is of a dark grey colour and hard in texture, breaking 

 with a species of conchoidal fracture. Its specific gravity is about T70. 

 According to analysis, the following are its principal constituents, viz. — 



Carbonic Acid, 43-00 



Lime, .. .. .. .. .. .. .. •• 55-50 



Foreign Matter, 1-50 



100-00 



It thus appears to contain about 98-50 per cent, of carbonate of lime, 

 and consequently would appear to be an excellent limestone for the 

 purposes of agriculture. 



The Magnesian Limestone. — The lower portion of this formation is 

 found in immediate succession to the coal measures. It is of a yellowish 

 white colour, and breaks with a dull earthy fracture. Its specific gravity 

 is about 2-64. 



A specimen from Conisbrough, near Doncaster, gave the following as 

 its chief constituent ingredients, viz. — 



Carbonic Acid, 46*50 



Lime, . . . . . . . . » • • • • • • • 35*00 



Magnesia, .. .. •« 17-75 



Red Oxide of Iron, 075 



Insoluble Matter 



10000 



