W^ ANTED 



Journal of Geology, vols. 1-23. 



Bulletin of Geological Society of America, vols. 



I, i6-i8. Index to vols. 11-20. 



Economic Geology, vol. i no. 7 or vol. i complete. 



Pomona. College Library. Cla.remont,Cal. 



Starved Rock State Park 

 and Its Environs 



By CARL O. SAUER 

 Department of Geology, University of Michigan 



GILBERT H. CADY 



Illinois State Geological Survey 



HENRY C. COWLES 



Professor of Ecology, University of Chicago 

 This is a thorough and interesting geographi- 

 cal study of the best-known feature of the 

 Illinois Valley. Part I is given up to the 

 geography of the park, its surface features 

 and their origin, and the exploration, settle- 

 ment, and development of the region; Part 

 II, to the geology of the park; and Part III, 

 to its botany. 



130 pages, cloth, $2.00, postpaid $2.10 



THE UNIVERSITY OF CHICAGO PRESS 



CHICAGO . . - - ILLINOIS 



Rhus Dermatitis 



Its Pathology and Chemotherapy 



By JAMES B. McNAIR 



^ The lack of any rational treatment for 

 the common infection resulting from 

 poison oak or poison ivy has suggested 

 a protracted study of the isolated prin- 

 ciple, in the hope that knowledge of its 

 characteristic properties may serve as a 

 basis for such treatment. 



^ Complete analysis of cause, effect, and 

 remedy has been attained by investi- 

 gating from the three distinct standpoints 

 of pharmacology, botany, and chemistry. 



$4.00, postpaid $4.15 



The University of Chicago Press 



Chicago - - . Illinois 



Essentials for the Microscopical Determination of 

 Rock-forming Minerals and Rocks 



By ALBERT JOHANNSEN 



Profesaor of Petrology 

 The University of Chicago 



A laboratory manual designed to provide students of petrology and geologists 

 interested in petrology with information on methods of determining microscopically 

 the points of separation between similar minerals and their modes of occurrence. 



This valuable volume contains, in addition to a folding alphabetical list so 

 placed that reference may be made to it without turning pages, the following 

 important features: "A Quantitative Mineralogical Classification of Igneous 

 Rocks" ; "A Summary of Petrographic Methods" ; "Modes of Occurrence of Various 

 Minerals"; "Rules for Computing Rocks from Their Modes"; and "Names Pro- 

 posed for Various Families." 



Cloth; $2.00, postpaid $2.15 



THE UNIVERSITY OF CHICAGO PRESS 



CHICAGO ILLINOIS 



