82 Scientific Intelligence. 



is so much decomposed that the material can only be dug out 

 and washed. 



In regard to the thorianite, the discovery of which excited 

 much interest some few years since, it is noted that the original 

 deposits in the alluvium have been practically exhausted. The 

 mineral evidently occurs in segregations in the pegmatite,, which, 

 in decomposed condition, has been mined to some extent but not 

 thus far with important results. The quantity exported in 1907 

 was 10 cwt. valued at 4,750 rupees. It may be noted, also, that 

 the amount of mica exported from Ceylon in 1907 was 426 cwt., 

 valued at 15,000 rs. ; of graphite the amount was 650,000 cwt., 

 valued at nearly 9,000,000 rs. The report closes with a list of the 

 mineral species known to occur in Ceylon. 



6. Mineral Resources of Virginia ; by Thomas Leonard 

 Watson, Ph.D. Pp. xxxi, 618, with 83 plates and 101 figures. 

 Lynchburg, Va., 1907 (J. P. Bell Co.). The Virginia- James- 

 town Exposition Commission.— This volume was planned in con- 

 nection with the Virginia-Jamestown Exposition, to call attention 

 to the remarkable resources of the state in its mineral wealth. 

 The state of Virginia has an unusually favorable position as 

 regards mineral resources, not only with respect to their diversity 

 and extent, but also the satisfactory conditions for work, due to 

 the mild climate and cheapness of labor, There has been a very 

 rapid development in this direction within the past few years, 

 the production having increased three-fold from 1902 to 1906 ; in 

 the last-named year the total valuation of production having been 

 $30,000,000. Professor Watson is well equipped for the work he 

 has done here, and in preparing this volume he has made use of 

 the extensive material available on the subject from the reports 

 of Prof. Rogers in 1835 down to the publications of the present 

 time. He has also been aided by contributions from Dr. R. S. 

 Bassler on cement and cement materials, by Prof. H. Ries on 

 clays, and by Prof. R. J. Holden on iron. The volume opens 

 with a brief statement of the general geology of the state, 

 with various columnar sections; this forms Part I. Part II 

 (pp. 16-187) is devoted to the building and ornamental stones, 

 cement, and clays; Part III (pp. 188-401) to non-metallic min- 

 erals, including pyrite, manganese oxides, mica, barite and gypsum, 

 coal, etc. ; while the closing part (pp. 402-582) discusses in detail 

 the ores of iron, copper, zinc and lead, gold and silver. The 

 volume is illustrated by numerous plates and maps, and cannot 

 fail to accomplish the object for which it was written. 



7. Minerals of Arizona: their Occurrence and Association, 

 with Notes' on their Composition ; Report to the Hon. J. H. 

 Kibbey, Governor of Arizona, by William P. Blake, Territorial 

 Geologist. Pp. 64. Tucson, 1909. — Arizona has been so rich in 

 its mineral production that this concise account by Prof. Blake 

 of the species thus far discovered will be found most convenient 

 for reference by all mineralogists. It is noted that in ] 908 the 

 copper production reached the large amount of 252,785,000 lbs. 



