| Peroxide of iron | 6.5 |
| Carbonate of lime | 13.5 |
| Silica and alumina (chiefly the latter) | 80.0 |
| 100. |
Siliceous—
| Peroxide of iron | 2.5 |
| Carbonate of lime | 23.5 |
| Silica, with a little alumina | 74.0 |
| 100. |
Whether any connexion can be traced between these last two and the two former, I leave for others to decide.
The following list of books may perhaps be useful to those who wish to further investigate the subject:—In
- Professor Phillips' Geology of Yorkshire,
- Young and Bird's Survey of the Yorkshire Coast,
- Dr. Fitton's Memoir of the Strata below the Chalk,
- Taylor's Hunstanton Cliff (Phil. Mag. vol. lxi.),
- Woodward's Geology of Norfolk,
- Rose on the Geology of West Norfolk (Phil. Mag. for the years 1835 and 1836),
will be found some account of the English Red Chalk. And in
- Sedgwick and Murchison on the Structure of the Eastern Alps (Geol. Soc. Trans. vol. iii. Second Series),
- Sir. R. I. Murchison on the Geological Structure of the Alps (Quart. Geol. Journal, vol. v.),
- Prof. T. A. Catullo on the Epiolitic Rocks of the Venetian Alps (Quart. Geol. Journal, vol. vii),
- Count A. de Zigno on the Stratified Formations of the Venetian Alps (Quart. Journal Geol. Soc. vol. vi.),
will be seen an outline of the Scaglia or Red Chalk of Italy.