Apeil 22, 1898.] 



SCIENCE. 



563 



here the confirmatorj^ evidence of moraines 

 is wanting. Remembering that the ' ab- 

 sence of moraines ' was one of the argu- 

 ments against the glacial theory but a few 

 decades ago, this map is very edifying. 



THE URAL MOUNTAINS. 



One of the first contributions to our scien- 

 tific literature resulting from the Interna- 

 tional Geological Congress in Eussia last 

 summer is by Dr. Persifor Frazer on a 

 ' Geological Section from Moscow to Siberia 

 and Return ' (Proc. Acad. Nat. Sci., Phila., 

 1897, 405-457), in which some interesting 

 geographical features of the Ural mountains 

 are set forth. Approaching this range from 

 the west, there is nowhere presented a bold 

 rugged landscape like that of the Alps or 

 the Caucasus ; a gradual ascent leads across 

 the disturbed ancient rocks, generally strik- 

 ing north and south, to the divide ; then a 

 moderate descent leads to a lower and open 

 plain, although the disturbance of the rocks 

 continues in full force. Karpinsky is quoted 

 as writing of this plain that, " although its 

 geological structure corresponds with a very 

 complex mountain region, the greater part 

 of it presents an area so flat that the relief is 

 less accidented than that of most of the 

 plains of European Russia;" and the removal 

 of the former mountains is ascribed by the 

 Russian geologist to abrasion by a Tertiary 

 sea, whose sediments stretch into Siberia. 

 From the divide one may look westward 

 and see the ridges separated by longitudi- 

 nal strike valleys, whose outlet is through 

 transverse gorges to the Russian plains ; to 

 the east, one looks across the old mountain 

 plain toward the boundless, lake-dotted 

 steppes of Siberia. Deep lakes, with ragged 

 shores and many islands, as well as numer- 

 ous swamps, abound on the old mountain 

 plain ; their drainage is eastward by streams 

 that have cut gorges in their middle course 

 and opened broad -floored valleys farther 

 forward. In the absence of all evidence of 



glacial action, several hypotheses are offered 

 to account for the lakes. 



W. M. Davis. 



NOTES ON INORGANIC CHEMISTRY. 

 In the Proceedings of the Chemical Society 

 (London) T. C. Porter has a note on the 

 volatility of sulfur. When heated to 100° 

 in a vacuum tube sulfur sublimes with some 

 degree of rapidity, the sublimate consisting 

 of very pale yellow drops, which remain 

 unchanged for several days ; at ordinary 

 temperatures even in a good vacuum there 

 is no perceptible sublimate, even in the 

 course of a year. In commenting on the 

 paper Professor Dewar said that if the vacua 

 are cooled with liquid air or oxygen a 

 visible distillation of sulfur takes place 

 even at ordinary temperatures. 



At the meeting recorded in the above 

 Proceedings Professor Bohnslav Brauner, of 

 Prague, was present for the purpose of read- 

 ing four papers on the chemistry of the 

 rare earths. The first two papers were on 

 thorium, describing his method of purifica,- 

 tion as ammonium thoroxalate, and atomic 

 weight determinations leading to the figure 

 232.42; agreeing with the work of Kriiss 

 and Nilson (232.45), but lower than that 

 of Cleve (234.5). The third paper was on 

 the compound nature of cerium, in which 

 the author holds that some unknown ele- 

 ment, of lower atomic weight (perhaps 

 about 110) and with no characteristic spark 

 spectrum, is present in the cerium from 

 cerite. The last paper on praseodymium 

 and neodymium is chiefly a study of the 

 compounds of praseodymium. From ex- 

 periments to determine whether the higher 

 oxid PrOj belongs to the type of PbO^ or 

 BaOj the author concludes that it is '' an 

 oxid of a new kind, belonging simulta- 

 neously to the ozonic oxids of the water 

 type, and to the antozonic oxids of the 

 hydrogen perosid type ; it is, in fact, the 



