LOWER CHALK—CHEMICAL COMPOSITION. 
839 
Analyses of the Totlernhoe Stone and the Chalk 
above it. 
Very few analyses appear to have been made of the Totternhoe 
Stone. An old one, of the stone quarried at Totternhoe, is quoted 
by Mr. Whitaker.* and states that “100 grains of the dried stone 
were found to contain . . . carbonate of lime 72, silex (in very fine 
white sand) 21, Alumina 7.” This, however, does not read like an 
accurate analysis. 
An analysis of a sample of the Burwell stone was made for the 
Geological Survey in 1880 by Dr. Frankland, and this is given 
below (A), quoted from the memoir on the Geology of Cambridge. 
A sample of the “ grey bed ” in Lincolnshire was analysed by Mr. 
J. W. Knights, of Cambridge, for Mr. Hill, in 1888. f 
A. 
B. 
Moisture at lOOdeg. (undetermined matter in B) - 
*66 
2*85 
Insoluble residue (silica and silicates) - 
11 *02 
7 *40 
Carbonate of lime ------- 
85*91 
86*40 
Carbonate of magnesia ------ 
trace 
2*15 
Alumina.- - - - 
•53 
| 1*20 
Peroxide of iron.- 
•68 
98-80 
100*00 
The insoluble residue in A was found by Dr. Frankland to have the follow¬ 
ing composition 
Silica - -.8’5 
Alumina -------- *32 
Protoxide of iron - -. 1*19 
Lime.’28 
Magnesia.*29 
Organic matter.*44 
_ 11-02 _ 
The following analyses are two of the series analysed by Mr. 
R. A. Berry (already mentioned); A is of the Totternhoe Stone at 
Arlesey near Hitchin, B, is of the highest part of the Lower Chalk 
just below the Belemnite Marl near Hitchin : — 
A 
B 
Loss on ignition. 
1*23 
1*17 
Calcium carbonate - 
79*11 
85*7 
„ phosphate. 
3*82 
*76 
„ sulphate ----- 
*61 
— 
Magnesium carbonate ----- 
*46 
1*41 
Lime -. 
1*71 
1-61 
Oxide of iron and alumina - - - - 
441 
•66 
Oxide of manganese ----- 
— 
*32 
Clay. 
3*03 
3*24 
Quartz. 
4T2 
3*11 
Colloid silica ------ 
1-02 
1*81 
Alkalis and loss in analysis - 
*18 
100-00 
•21 
100*00 
* Mem. Geol. Survey, Vol. iv. p. 41 (1872). 
t Quart. Journ. Geol. Soc., Vol. xliv. p. 359. 
4219. Z 
