464 ScientiJiG Intelligence. 



geology. Some optical mineralogy is introduced and the use of 

 the microscope indicated. A further advantage is that a con- 

 siderable amount of physical geology, in so far as it relates to the 

 subject, is brought in. A great help will be found in the numer- 

 ous well executed half-tones of photographs, especiall\^ those of 

 rock sections showing texture, etc. A more careful selection of 

 more modern and better executed analyses of rocks and more of 

 them, would have been of advantage. The volume is well printed 

 and in convenient form. l. v. p. 



6. The Terlingua Quicksilver Deposits^ Brewster County, Texas. 

 The University of Texas Mineral Survey, Bull. No. 4, pp. 74. — 

 These deposits are of quite recent development and are as yet 

 only worked in a small way by means of open pits. They are 

 located in the center of an extensive area of Cretaceous sedimen- 

 tary rocks, which have been much faulted and into which igneous 

 rocks have been intruded. The ore deposits are found within 

 the sedimentary rocks and usually at a short distance from some 

 igneous intrusion. The chief ore mineral is cinnabar, with w^hich 

 is associated some iron oxides and large amounts of calcite. The 

 ore occurs in vein formations of a number of different types, none 

 of which are very wide and most of which vary considerablj^ in 

 their richness. It is thought that the veins and their ore contents 

 will be found to continue in depth. The ore is treated near the 

 mines in furnaces similar to those in use in California. The total 

 output of the district up to the end of 1901, is estimated at 3,700 

 flasks of mercury, of which 3,000 flasks were produced during 

 the year 1901. w. e. f. 



7. Kotes on ISfeio Minerals. — Ba.umhaueeite is a sulpharsenite 

 of lead having the formula 4PbS-3As„S3. The analysis made by 

 H. Jackson gave the following results : 



Found, Calculated. 



Pb._. - 48-86 48-75 



S 24-39 24-61 



As 26-42 26-64 



99-67 100-00 



The specific gravity was determined as 5-329. It is monoclinic 

 in its crystallization, having the axial relations, 



a-.l'.c- 1-136817 :1: 0-947163 ; ^ = 82° 42|'. 

 The crystals closely resemble those of dufrenoysite and jordanite 

 in appearance. They may be distinguished from dufrenoysite 

 by the marked oblique development of the zone 100—001, and 

 from jordanite by the absence of twin striations and by the color 

 of the streak. The mineral is described by R. H. Solly and 

 named in honor of Dr. H. Baumhauer, Professor of Mineralogy 

 in the University of Freiburg. — Min. Mag., xiii, 60. 



A new analysis of material from the original locality has been 

 made by G. T. Prior and shows Killrickenite to be identical 

 with the earlier described geocronite. The important difference 

 between the new analysis and the original analysis is in the find- 



