474 



Scientific Intelligence. 





McConnell in the copper regions of White Horse district ; Leach 

 and McEvoy on the coal basin of Fernice in the Crow's Nest 

 Pass coal field ; Dowling on the western side of Hudson, where 

 rocks formerly represented as Lauren tian were shown to be of 

 Lower Cambrian age ; Barlow on the Sudbury nickel and copper 

 district ; Adams on the Haliburton district ; Chalmers on the 

 superficial deposits' of the interlake peninsula of Ontario exploit- 

 ing for gas, petroleum and water ; Laflamme made investigation 

 of the Middle Silurian of Anticosti, bringing in numerous fossils ; 

 Bailey and Poole on the Carboniferous deposits of New Bruns- 

 wick. These and many other lines of research are the steady 

 progress of previous years. n. s. w. 



2. Field Operations of 'the Division of Soils ; report for 1900 

 by Milton Whitney, Chief of Division U. S. Dept. Agriculture. 

 473 pp. ; 51 pis. ; 47 figs. ; also 24 colored soil maps. — The work 

 of the Division of Soils for 1900 covered a wide area. The 

 eastern division, in charge of C. W. Dorsey, made surveys in 

 Maryland, Pennsylvania, Ohio and North Carolina; the western 

 division, in charge of Thomas H. Means, was at work in Utah, 

 Arizona and California. 4,465 square miles were mapped on a 

 scale of one inch to the mile. The laboratory work for the 

 division included investigation on the physical and chemical 

 properties of soils. 



3. The Mineral Wealth of the Black Hills ; by Cleophas C. 

 O'Haera. South Dakota Geol. Survey, Bull. No. 3. Pp. 82; 

 pi. 22. — Dr. O'Harra of the South Dakota School of Mines has 

 described the economic mineral deposits of the Black Hills and 

 includes in his treatise a general summary of the history, condi- 

 tions, and apparent possibilities of their development. 



4. Corimclum Twins ; by Wm. E. Hidden. (Communicated.) — 



Crystals of corundum, gray and ruby -red 



in color, twinned parallel to the base 



c (0001), have been found sparingly in 



the " In situ " mine (of ruby, pink and 



gray corundum), Coler Fork of Co wee 



Creek, Macon County, North Carolina. 



They were first observed by the writer 



in 1898, upon crystals from a feldspar 



vein. The two best examples measure 



six millimeters in diameter and length. 



They are characterized by reentrant 



angles (n, 2243) on the prismatic faces (a, 1120) and some slight 



natural corrosion. (See figure, drawn by Mr. John C. Blake of 



the Yale Mineralogical Laboratory.) 



5. Genesis of Ore Deposits ; published by the American Insti- 

 tute of Mining Engineers. — During the past few years several 

 important papers on ore deposits have been published by the 

 Institute of Mining Engineers. These have now been collected 

 into a single volume. The first paper, from which the book takes 

 its title, is the celebrated treatise by Franz Posephny which was 



