WILLIAM BARTON ROGERS. 411 



the geological survey of the State, having, while a professor at 

 William and Mary, begun his geological labours with an ex- 

 amination of the Tertiary formation of this region, of which he 

 published, in conjunction with his brother Henry D. Rogers, 

 two memoirs in the Transactions of the American Philo- 

 sophical Society. In June, 1834, and May, 1835, he had pub- 

 lished also, in the Farmers' Register, three papers on the 

 Green Sand and Marl of Eastern Virginia, pointing out their 

 value as fertilizers. At this time, besides other chemical re- 

 searches, he made an analysis of the waters of the Virginia 

 mineral springs, the results of which have appeared in various 

 publications. 



He remained at the head of the geological survey until it 

 was discontinued in 1842, having published a series of annual 

 reports and collected further materials, for the completion and 

 publication of which, however, no provision was made by the 

 State. All his brothers were from time to time among his 

 assistants in field and laboratory work. While at the univer- 

 sity he published for the use of his students a short treatise 

 on the Strength of Materials (Charlottesville, 1838), and a 

 volume on The Elements of Mechanical Philosophy (Bos- 

 ton, 1852). During this period of his life, besides the cares of 

 his professorship and of the survey, he occupied himself with 

 original researches in various departments of science, partly 

 geological, in connection with his field work, and, after the sur- 

 vey ended, chiefly in chemistry and physics. 



In 1840 the "Association of American Geologists and 

 Naturalists " was organized. In this society, embracing Hitch- 

 cock, Hale, Vanuxem, the four brothers Rogers, Conrad, Em- 

 mons, and others engaged in active scientific research, Prof. 

 Rogers took a leading part, as will be seen by referring to its 

 Transactions. 



One of the more important of his geological researches 

 published at this time concerned the solvent power of water, 

 especially when charged with carbonic acid, on various miner- 

 als and rocks, and showed the extent of this action in Nature. 

 In connection with his brother Robert, Prof. Rogers was the 

 first to investigate this subject. 



From his examinations of the Virginia coal deposits he dis- 

 covered that the condition of any coalbed stands in a close 

 genetic relation to the amount of disturbance to which the 



