

Intelligence and Miscellaneous Articles. 227 



feet. 



*3 pM (0. White or grey sand, more or less coherent, and with 

 1 fe J occasional ferruginous stains, sometimes quarried for 

 :t > ) "building-stone. A plant-bed is usually found in this 



sand 12 



D. A series of very variable beds, composed sometimes of 

 ferruginous sandstone in thin layers, which overlie cal- 

 careous beds containing shelly zones, false bedding being 

 frequent. Sometimes the whole section consists of cal- 

 careous rock with false bedding ; sometimes it presents 

 a series of beds of compact ferruginous sandstone with 

 no fossils. In one instance the entire section consists 

 of white sand and sandstone, with no fossils 30 



Coarse Oolitic or subcrystalline Limestone, with fossils, 

 overlying a calcareo-arenaceous slate, like Colleyweston 

 Slate 4 



E. Beds chiefly consisting of Ironstone, containing Rhyn- 

 chonella variabilis and JR. cynocephala, and Ammonites 



►3 Lh3 ( bifrons at the base 35 



This general section, the author stated, might be accepted as a 

 typical section of a considerable portion of the county of North- 

 ampton. 



In his concluding remarks the author referred to the great lime- 

 stone which marked the country about Stamford and, traversing 

 Eutland, attained its greatest thickness in Lincolnshire. This 

 limestone was proved by its palseontological contents to be Inferior 

 Oolite ; and its place, with reference to the beds described in the 

 paper, was shown to be in the interval (marking the line of uncon- 

 formity) between B and C of the general section. It thus tended 

 to confirm the statement of the author that the line of division 

 between the Great and the Inferior Oolite in the neighbourhood of 

 Northampton occurred at that point. 



The paper was illustrated by the exhibition of a large collection 

 of fossils from the several areas, including some new species, promi- 

 nent among which was a new Starfish, named, in compliment to 

 the author, " Stellaster SharpU^ by Dr. Wright, F.K.S.E., E.G.S., 

 and described by him in a Note appended to this paper. 



XXVIII. Intelligence and Miscellaneous Articles. 



ON THE EXTENSION OF OHm's LAWS TO ELECTROLYTES, AND ON 

 THE NUMERICAL DETERMINATION OF THE RESISTANCE OF DI- 

 LUTE SULPHURIC ACID BY MEANS OF ALTERNATE CURRENTS. 

 BY MM. F. KOHLRAUSCH AND A. NIPPOLDT. 



HpHE special resistance of electrolytes is complicated with the pheno- 

 ■*- mena of polarization which most frequently accompany electrolysis. 

 To determine the first element it must be freed from the influence 

 of the second, which presents great difficulties. The authors think 

 they have removed these difficulties by causing induction-currents to 

 pass through the liquids alternately in opposite directions. This 

 method is not new j it has already been employed by MM. De la 



