50 THE PHYSICAL FEATURES OF CECIL COUNTY 



Maclure, ¥m. Observations sur la Geologie des Etats-Unis, sur- 

 vant a expliquer une Carte Geologique. 



Journ. de phys. de chim. et d'hist. nat. tome lxix, 1809, pp. 204-213. 



1811. 



Maclure, Wm. Suite des observations sur la Geologie des Etats- 

 Unis. 



Journ. de phys., de chim. et d'hist. nat., tome lxxii, 1811, pp. 137-165. 



1817. 



Maclure, Wm. Observations on the Geology of the United States 

 of America, with some remarks on the effect produced on the nature 

 and fertility of soils by the decomposition of the different classes of 

 rocks. With two plates. Phila., 1817. 12mo. 



Republished in Trans. Amer. Phil. Soc., n. s., vol. i, 1818, pp. 1-91. 



Leon. Zeit., vol. i, 1826, pp. 124-138. 



1818. 



Mitchill, Samuel L. Cuvier's Essay on the Theory of the Earth. 

 To which are now added Observations on the Geology of North Amer- 

 ica. New York, 1818. 8vo. 431 pp., plates. 



1828. 

 Carpenter, George W. On the Mineralogy of Chester County, 

 with an account of some of the Minerals of Delaware, Maryland and 

 other Localities. 



Amer. Jour. Sci., vol. xiv, 1828, pp. 1-15. 



Also published separately, 12mo, 16 pp., Phila., 1828 (Md. ref., p. 14). 



1829. 

 Livermore & Dexter. A collection of fossil earths, and minerals 

 from the deep cut of the Delaware and Chesapeake Canal, with memoir 

 and profile of geological strata developed in progress of work. 



Proc. Amer. Phil. Soc., vol. xxii (2), 1884, p. 594. 

 Mentioned in Minutes Proc. Amer. Phil. Soc, 1743-1838. 



1830. 



Morton, Samuel G-. Synopsis of the Organic Eemains of the Fer- 

 ruginous Sand Formation of the United States, with Geological 

 remarks. 



Amer. Jour. Sci., vol. xvii, 1830, pp. 274-295; vol. xviii, 1830, pp. 243-250. 



