6o8 THE POPULAR SCIENCE MONTHLY. 



Mines of Eastern Virginia ; " and " On the Physical Structure of the 

 Appalachian Chain," etc. In the first of these papers Prof. Rogers 

 showed that the formation in question, instead of being of an age 

 anterior to the Carboniferous, as had been maintained by Maclure 

 and R. C. Taylor, was of Mesozoic time. In the second paper he 

 described the position of more than fifty thermal springs in the Ap- 

 palachian belt, occurring in an area of about 15.000 square miles, 

 deducing the law that these thermal springs issue from anticlinal 

 axes and faults, or from points very near such lines, and, in connec- 

 tion with their chemistry, proving the important fact of the great 

 preponderance of nitrogen in the free and combined gases of these 

 springs. The observations on subterranean temperature recorded in 

 the third paper were the first published confirmation, as regards the 

 United States, of the law of augmenting temperature beneath the 

 surface of the earth, although similar observations had been made by 

 Humboldt in Mexico. The memoir on the physical structure of the 

 Appalachian chain, etc., was the joint work of Profs. W. B. and H. D. 

 Rogers, founded on their explorations of this belt in Pennsylvania 

 and Virginia, and its prolongation toward the southwest and north- 

 east. The novelty and importance of its generalizations were at 

 once recognized in Europe as well as at home, and gave the authors, 

 "the Gebriider Rogers," a prominent place among contemporary 

 geologists; and, so far as the development of the physical structure 

 of the Appalachians is concerned, this memoir is still regarded as of 

 classical value. 



Prof. Rogers was chairman of the Association in 1845, and again 

 two years later, when it was expanded into the " American Associa- 

 tion for the Advancement of Science," at the first meeting of which 

 he presided until it was fully organized. 



In connection with his brother, Robert E. Rogers, now become 

 his colleague as Professor of Chemistry and Materia Medica in the 

 university, he published a number of important chemical contributions, 

 relating chiefly to new or improved methods in chemical analysis and 

 research, in Sillimarfs Journal, between 1840 and 1850. Among these 

 were papers " On a New Process for obtaining Pure Chlorine ; " "A 

 New Process for obtaining Formic Acid, Aldehyde, etc. ;" " On the 

 Oxidation of the Diamond in the Liquid Way ; " " On New Instru- 

 ments and Processes for the Analysis of the Carbonates ; " " On the 

 Absorption of Carbonic Acid by Liquids," an extended investigation; 

 and "On the Decomposition of Rocks by Carbonated and Meteoric 

 Waters," a paper of much interest in its geological bearings. 



In the volume of the " Transactions of the British Association " 

 for 1849, Prof. Rogers called attention to the existence of true coal- 

 measures below the horizon of the Carboniferous limestone in the 

 Appalachian belt as discovered by him in the Virginia survey, and 

 referred to in his annual reports. 



