424. Scientific Intelligence. 



Technology. 652 pp. Washington, 1S90 (U. S. Geol. Survey, J. 

 W. Powell, Director). — Another volume — the sixth — of this valu- 

 able series has appeared, under the able editorship of Mr. David 

 T. Day, and presents the condition of our mining industries for 

 1888. The volume opens with the usual concise summary for the 

 different metals, etc., and detailed chapters on each subject by 

 individual specialists follow. Some of these chapters are of great 

 fullness and interest as, for example, that in Coal (pp. 168-394) by 

 Charles A. Ashburner. As illustrating the effect of a special 

 demand (in this case, the manufacture of incandescent gas burners) 

 in creating a supply of substances hitherto supposed to be 

 extremely rare, it is interesting to note that during 1887-88, 

 25 tons of zircon were mined in North Carolina, 4 tons of 

 monazite, 1 ton of allanite, 600 pounds of samarskite and $500 

 worth of yttrium minerals. 



7. Elements of Crystallograjihy for students of Chemistry, 

 Physics and Mineralogy, by George H. Williams. 250 pp. 

 12mo. New York, 1890, (Henry Holt & Co.). — The subject of 

 crystallography is often regarded by the student as somewhat 

 repulsive, but to those acquainted with its real simplicity it is 

 obvious that the difficulty is not so much intrinsic as to be found 

 in the way in which it is ordinarily presented. The excellent 

 little volume which Dr. Williams has prepared can hardly fail to 

 do much to remove this reproach and to make the subject 

 thoroughly attractive. The explanations of the morphological 

 relations of crystals are so simple and full and the style so clear 

 that a conscientious student using it will find that the ordinary 

 difficulties disappear while the mastery of the subject will fol- 

 low as a matter of course. A knowledge of crystals is obviously 

 of importance not only to the mineralogist but also to the chemist 

 and physicist and to the latter class especially this book will be 

 of great assistance. 



8. Mumpjite, a new mineral. — G. Firtsch has given the name 

 Rumpfite, after Prof. J. Rumpf, of Graz, to a miueral allied to 

 the chlorites occurring in aggregates having a fine scaly to 

 granular structure in cavities in magnesite near St. Michael in 

 Upper Syria. It has a greenish-white color ; the hardness is 

 1-5, and the specific gravity 2-675. Before the blowjnpe it is 

 infusible. An analysis gave : 



Si0 2 



Alo0 3 



FeO 



MgO 



CaO 



HoO 



30-75 



41-66 



1-61 



12-09 



0-89 



13-12 = 100-12 



It was found that practically no water was lost up to 360°, but 

 at a dark red heat 9 per cent went off, while the remainder was 

 expelled at full ignition. — Per. Ak. Wien, xcix, July, 1890. 



9. Polybasite from Colorado. — Dr. F. M. Endlich has iden- 

 tified the rare mineral polybasite at the Yankee Boy mine, Ouray, 

 Colorado. It occurs in tabular crystals, hexagonal in outline, 

 with pyrargyrite in cavities in a quartzose gangue. The deter- 

 mination has been confirmed by Penfield who finds the prismatic 

 angle to be very nearly 60°; Miers gives 60° 10' as the result of 

 recent observations. 



