October 31, 1913] 



SCIENCE 



625 



of a steep wall and there was one pocket of a 

 lenticular form containing tlie mineral, with 

 a cross-section of about 3 by 10 inches. A 

 few feet away there was an imbedded layer of 

 the material showing at the surface for a dis- 

 tance of about eight feet. This layer was 

 sloping down at an angle of about 10 degrees, 

 measuring at the upper end about IJ inches 

 and thickening out toward its lower end to 

 about 3 inches. At a deposit in the Paradox 

 Valley, Colorado, the same mineral occurred in 

 small pockets imbedded in and lying between 

 the carnotite and high-grade vanadium sand- 

 stone. At Green River, Utah, there was a 

 considerable amount of associated gypsum. 



The cracks, interstices, and part of the ex- 

 posed surface of the mineral are partly coated 

 with carnotite. The carnotite can be easily 

 removed from the black mineral by sliming the 

 crushed carbonaceous material. The black 

 mineral on being dried shows a high activity, 

 somewhat higher than would be expected from 

 the uranium content. 



The mineral bums with a feeble flame and 

 on ignition leaves a light brown ash. 



As already stated, the mineral is intimately 

 associated with carnotite, so much so that it 

 would appear that the carnotite may be a 

 secondary transformation product of this min- 

 eral. The structure is massive and brittle; 

 the luster metallic, dull to shiny and sub- 

 metallic; the color black; fracture uneven; 

 specific gravity 1.972 to 1.984; hardness 3 to 

 3.2; and streak black to brownish black. 



A typical preliminary analysis of the min- 

 eral made by 0. F. Whittemore, of the Denver 

 office of the Bureau of Mines, after the car- 

 notite. had been removed and its absence con- 

 firmed by careful examination with a micro- 

 scope is as follows: 



Per Cent. 

 Water 7.45 



Carbonaceous material 74.30 



Silica 07 



V,0^ 1.62 



r'^O^ 9.43 



Fe,0^ 3.29 , 



Afo^ Ln-^y 



Several analyses appear to show that the 

 uranium content is fairly constant, but the 



vanadium varies, one result being as low as 

 0.38 per cent. This would seem to indicate 

 that a part, if not all, of the vanadium is in 

 the form of roscoelite or some similar mineral 

 which was not completely removed by the 

 mechanical treatment. 



Further work is being done on this mineral, 

 which will be published later, and we desire to 

 reserve priority rights for the completion of 

 the work, and the naming of the mineral. 



Earl L. Kithil 



U. S. BxTEEAU OP Mines 



SCIENTIFIC BOOKS 



School Hygiene. By Fletcher B. Dresslae, 

 Specialist in School Hygiene, United States 

 Bureau of Education. The MacmiUan Com- 

 pany. 1913. Pp. 369. 



Educational hygiene has four leading and 

 interrelated divisions: (1) the hygiene of 

 physical and mental growth; (2) health and 

 medical supervision of schools ; (3) the hygiene 

 of instruction, and (4) the hygiene of the 

 school plant. 



Dr. Dresslar's book deals mainly with the 

 last division. Of the twenty-six chapters, 

 eighteen deal chiefly with the school plant, 

 eight with problems relating to the hygiene of 

 growth, two with the hygiene of instruction, 

 and one with medical inspection. 



According to the preface, " It is the pur- 

 pose of this book to set forth in a simple and 

 untechnical way some of the hygienic re- 

 quirements of school life, and to suggest, when- 

 ever it seems necessary, how these require- 

 ments may be put into practise. No attempt 

 has been made to treat any phase of the sub- 

 ject exhaustively. The purpose has been to se- 

 lect the most important topics, and to deal with 

 them in a manner as simple as is consistent 

 with the truth. It has not been written for 

 the specialists in school hygiene, but for busy 

 teachers." 



The volume is a much-needed and extremely 

 valuable addition to our literature on school 

 hygiene. The author's extensive first-hand ac- 

 quaintance with the problems of schoolhouse 

 construction and equipment adds very greatly 



