June 8, 1883.] 



SCIENCE. 



521 



Archeological lithology. — Jannettaz and Mi- 

 chel from chemical and microscopic examination of 

 two fragments of images obtained in Oaxaca, con- 

 clude that the rock is serpentine. Like examination 

 of a pierced cylindrical baton from Tetihuacan caused 

 it to be regarded as a microcrystalline albite. The 

 rocks were respectively colored greenish gray, deep 

 green, and milk-white with a greenish tinge. — {Bull. 

 soc. min. France, April, 1883. ) m. e. w. [1029 



Meteorites, 

 Fusion structures in meteorites. — The review- 

 er having expressed himself favorably {24) regard- 

 ing an abstract of Wiechraann's paper, it becomes 

 necessary, on examination of the completed form 

 just published, to withdraw his commendation. The 

 paper is a rambling, nearly worthless essay. So far 

 as we can judge, the conclusions appear to be in the 

 main correct ; but they are mere guesses so far as this 

 paper goes. The plates are coarse and unnatural. 

 The only real evidence the article contains (which 

 can be found on almost every page) shows the author 

 to be destitute of the elements of the knowledge 

 necessary for the work he has undertaken. — {Ann. 

 N. Y. acad. sc, ii. 2S9.) m. e. w. [1030 



MINERALOGY. 



Pachnolite and thomsenolite — Since the analy- 

 ses of J. Brandl have shown these very similar 

 minerals to have the compositions (Al F3, Ca Fo, 

 NaF) and (Al F3, Ca Fj, Na F, H..O) respectively, 

 Des Cloizeaux has subjected the same to renewed 

 optical and crystallographic examination. The crys- 

 tals of pachnolite are always very small, and associated 

 intimately with the thomsenolite. When heated in 

 the closed tube, they decrepitate violently, giving no 

 water. They are referred to the monoclinic system, 

 with axial relation e:b:a = 1.326676 : 1 : 0.859495 /3 = 

 89° 41'. The thomsenolite is distinguished by its 

 perfect basal cleavage. When heated in the closed 

 tube it decrepitates violently, giving off acid water. 

 The crystals are monoclinic, with the faces of the 

 hemi-octahedron and prism striated parallel to their 

 intersection with the base, and having the axial re- 

 lation c : b : a= 1.0883 : 1 : 0.998741 ^ = 89° 12'. 



These two minerals, which have been much con- 

 founded and united, are thus shown to be distinct, 

 not alone in chemical, but also in physical and 

 crystallographic properties. — {Bull. soc. min., v. 317. ) 

 s. L. P. [1031 



PHYSICAL GEOGBAPHY. 



Ripple-marks. — The cause of the production of 

 ripple-marks in marine sands, lately investigated by 

 A. R. Hunt {Proc. roy. soc, xxxiv. 1882, 1), has been 

 further studied by C. de CandoUe. He shows that 

 they are caused by a horizontal oscillating or inter- 

 mittent motion of the bottom-water, generally arising 

 from the effect of wind on the surface, and makes it 

 probable that they are produced at very considerable 

 depths, and in directions independent of the surface- 

 winds blowing. Such ripples are always formed on 

 the surface of a viscous mass when a liquid moves 

 back and forth, or intermittently forward, over it. 

 Attention is called to the possibility that rippled 

 cirrus clouds may have a similar origin, and to the 

 resemblance between some artificial ripples and cer- 

 tain organic forms. Several well executed plates 

 illustrate the paper. — {Arch. sc. phys. nat., ix. 1883, 

 241.) w. M. D. [1032 



Patagonia. — C. Martin calls attention to the 

 contrast, dependent on the winds and consequent 

 rain, between the country east and west of the 



southern Andes. North of lat. 40° S., where even 

 the passes approach the height of Mont Blanc, this 

 contrast is strongly marked; but farther south the 

 Cordillera is broken, and gives more open passage to 

 the moist winds. At its eastern foot the numerous 

 and large lakes are all fresh, having overflow during 

 at least part of the year. Farther eastward the 

 country becomes dry and barren, though nowhere 

 being a desert of drifting sand. Its small lakes are 

 saline. The Patagonian Ajides, therefore, do not 

 constitute a continuous range, but consist of a series 

 of moderately high volcanoes on the ragged western 

 border of the tableland, deeply cut by fiords and 

 by rivers, that in some cases rise at a considerable 

 distance from the Pacific coast, as found by the ex- 

 plorers. Cox, Fonck, and Musters. Forests extend 

 as far north as lat. 35° S., but there they are found 

 only on the mountain spurs. South of lat. 37° the 

 lowlands also are forest covered, except where occa- 

 sionally cleared by the Indians, who have, till lately, 

 occupied this district to the exclusion of Spaniards 

 and Chilians, and again between Valdivia and Osorno 

 (lat. 40° to 42° S. ), where opened by German colo- 

 nists. The mainland and archipelago of the fiord 

 region, where the Chilian hydrograplier, Simpson, has 

 counted over one thousand islands, are well wooded, 

 the trees extending above the foot of the glaciers, up 

 toward the snow-line. A brief description is given 

 of the more important forest-trees. A peculiar build- 

 ing of lake-barriers Is described (whether on sufficient 

 observation or not does not appear) at several points 

 in the southern fiords; for example, in the bay into 

 which the glacier from the flank of San Valentino 

 (3,870 met.) gives off its bergs, which, on melting, form 

 a ha,T like a moraine, and in time enclose a part of 

 the bay, which then becomes fresh by outward drain- 

 age. One such lake has already been formed here, 

 and another is forming. — {Mitth. erdk. Halle, 1882, 

 88.) w. M. D. [1033 



GEOGBAPHY. 

 (Europe.) 



Surface and structure of "Wurtemberg. — Be- 

 ginning with a quotation from Murchison, — "No 

 really good topography can be made by any surveyor 

 who neglects geological data," — E. Hammer de- 

 scribes the close relation between the geological 

 structure of Wurtemberg and the form of its eroded 

 surface. Valleys cut in the bunlsandstein have even- 

 ly rounded side-slopes ; in the muachelkalk the slope 

 begins abruptly at the line of a hard upper stratum, 

 and sinks directly to the base; in the keuper the 

 slope is broken by steps or terraces of harder and 

 softer layers. Most of the larger streams follow the 

 muschelkalk, and their upper courses meander so 

 irregularly that the most ordinary topographic map 

 reveals its presence. The forms of the successive 

 lias, Jura, and tertiary deposits are given in detail. In 

 upper Swabia, glacial deposits present their peculiar 

 landscape of systemless hills and hollows, with drain- 

 age so imperfectly established that peat-swamps oc- 

 cupy a considerable part of the surface. The lack of 

 illustrations decreases the value of this paper; but 

 its method is excellent, and should find many fol- 

 lowers. — {Kettler's zeitschr. wiss. geogr., ill. 93, 148.) 

 w. M. D. [1034 



Area of Italy. — The official estimates of the 

 area of Italy give a surface of 296,323 □ kil., accord- 

 ing to figures established in 18i>4 ; but in the past 

 year several statistical almanacs have changed this 

 to 288,.540 □ kil., according to the results of Gen. 

 Strelbitsky {Superficie de V Europe, 1882). Prof. G. 

 Marinelli of the university of Padua does not ap- 



