245 
ON SOME SINGULAR NODULES IN THE MAGNESIAN LIMESTONE. 
BY REV. J. STANLEY TUTE, B.A. 
In the quarry of Magnesian Limestone near Wormald Green 
there occur some singular nodules of an impure silicate of lime, which 
appear to be of sufficient interest to be worth putting on record. They 
seem to form a connecting link between the Permian beds of York- 
shire and those of Durham. I am informed by Mr. R. Howse, of 
Newcastle, that simular nodules are found at South Shields, and 
at Fulwell, near Sunderland, an analysis and description of which 
appeared in the Transactions of the Tyneside Naturalists' Field 
Club, by Mr. Robert Calvert Clapham, and read Dec. 23, 1861,* The 
following is a copy of the analysis of the nodules from the Trow 
Rocks : — 
Silica ... ... .. 78.00 
Alumina ... ... .. 1.50 
Peroxide of Iron ... ... — 
Carb. Magnesia ... ... 9.20 
„ Lime ... ... 11.10 
Total... ... 99.80 
Upon this he remarks " It is therefore not a flint (properly so 
called), but a mineral consisting of silica, and carbonate of lime and 
magnesia, which may yet require to be named. It is possible that 
it may have existed as some organic substance, of which the present 
mineral may retain some of the original form. 
''Another specimen of a similar substance, but much more flinty 
in its appearance, found at Fulwell, and sent me by Mr. J. "W. Kirkby, 
approaches much more nearly to the composition of flint in the quan- 
tity of silica, but contains a greater percentage of other matters than 
that mineral. It is composed as under : — 
Silica ... ... ... ... 96.5 
Alumina and Iron ... ... 1.2 
Carb. Lime ... ... ... 1.6 
Magnesia ... .. ... trace 
Total ... ... 99.3 
* See Vol. v., Part 2, page 124, xxiii. 
