870 



SCIENCE. 



[N. S. Vol. XI. No. 283. 



dium thiocarbonate. When treated with chlorin 

 the chlorids of sulfur and silicon are formed 

 and this reaction is used by the authors to de- 

 tect thiosilicates in natural and artificial sili- 

 cates. Thus they find 0.007 percent. ofSiSj 

 in Vesuvius lava, up to 0.1 per cent, in differ- 

 ent blast furnace slags, and 0.174 per cent, in 

 ultramarine. They suggest that the sulfur in 

 many sulfur springs may be due to the decom- 

 position of thiosilicates. 



The last Chemical News contains the transla- 

 tion of a paper on krypton, communicated to 

 the Berlin Academy by Professor Ludenburg 

 and Professor Kruegel, of Breslau. Availing 

 themselves of the possibility of obtaining larger 

 quantities of liquid air, they examined the resi- 

 due of 850 liters. These liters of this liquid 

 residue gave 2300 liters of gas which was freed 

 from oxygen and nitrogen. The final residue 

 of 3.5 liters of gas was condensed in liquid air 

 and then fractioned. The earlier fractions were 

 chiefly argon, though even the second of the 

 six fractions showed clearly the green krypton 

 line. After the fifth fraction was boiled off 

 there remained a crystalline residue melting at 

 about — 147°. The gas in this fraction proved 

 to be nearly pure krypton, though some argon 

 lines were present in the spectrum. Ramsay 

 had suggested for krypton the density of 80-82, 

 but two determinations with Ladenburg's kryp- 

 tongave 58.67 and 58.81, using about 16 c.c. of 

 the gas which had been crystallized. The au- 

 thors suggest for the inert gases a position be- 

 fore Group I. as follows : Helium = 4 before 

 lithium, neon = 20 before sodium, argon = 39 

 before potassium, and finally krypton ^= 59 be- 

 fore copper. The authors are continuing their 

 researches which promise interesting results. 

 J. L. H. 



CURRENT NOTES ON PHYSIOGRAPHY. 



THE DIVERSION OF THE YELLOWSTONE. 



The questions raised by the unequal develop- 

 ment of different parts of the Yellowstone drain- 

 age system within the National Park, as shown 

 upon the topographic maps of the IT. S. Geolo- 

 gical Survey (see Science, V., 1897., 577), are 

 answered by J. P. Goode in an article on ' The 

 Piracy of the Yellowstone ' (Journ. Geol. , vii, 

 1899, 261-271). It is there explained that the 



postglacial discharge of Yellowstone lake, when 

 it stood about 200 feet higher than today, was 

 orignally southwestward through a deep notch 

 between Overlook and Channel mountains to the 

 head of Snake river. The lower part of the can- 

 yon by which the lake is now discharged north- 

 ward was then like its several neighbors in the 

 rhyolite plateau, occupied by an active stream 

 whose length was increasing by headward ero- 

 sion. More favored than its fellows, this stream 

 happened to gnaw through the divide that 

 previously enclosed the lake basin and thus the 

 waters of the lake were diverted to a northward 

 discharge. The canyon was rapidly deepened, 

 and the former outlet to the Snake river was 

 abandoned. To-day the floor of the old outlet 

 is poorly drained ; puny streams start on its 

 marshy course and flow to the opposite oceans. 

 The falls in the new canyon are ascribed to the 

 resistance of an undecomposed portion of rhyo- 

 lite, on which the erosion of the river is re- 

 tarded. 



This essay does not explain the origin of the 

 deep channel by which the lake was dis- 

 charged to Snake river. The mountains in 

 which the channel was cut seem to have been 

 originally much higher than the divide through 

 which the Yellowstone canyon has recently 

 been eroded. On this point we may have fuller 

 details in the expected Survey monograph on 

 the Yellowstone Park. 



MILL ON SOUTHWEST SUSSEX. 



Dr. H. R. Mill, librarian of the Royal Geo- ^ 

 graphical Society of London, proposed several 

 years ago that a detailed geographical descrip- 

 tion should be prepared for the sheets of the 

 one-inch English ordnance survey (see Science, 

 III., 1896, 799 ). He has now made a first con- 

 tribution to the scheme in 'A Fragment of the 

 Geography of England : Southwest Sussex ' 

 {Geogr. Journ., xv, 1900, 205-227, 353-373), 

 a compendious account of the various features 

 of that interesting district. The essaj' and its 

 illustrations are excellent in many respects, and 

 called forth deserved praise when presented at 

 a meeting of the Society ; but the pages that 

 are concerned with physiography leave some- 

 thing to be desired, inasmuch as they do not 

 cover their subject broadly or uniformly. The 



