356 



SCIENCE. 



[N. S. Vol. XVI. Ko. 4(Mt. 



been entombed at the beginning of the loess 

 deposition, which would refer it to the lowau 

 stage of the Glacial period, long after the ice- 

 sheet had receded from Missouri and Kan- 

 sas, but while it still enveloped northern Iowa 

 and nearly all of Wisconsin and Minnesota. 

 In other words, it belonged to a time before 

 the prominent moraines of these last-named 

 states were formed on the borders of the wan- 

 ing ice-sheet. The very old Kansas glacial 

 drift, including many boulders of the red 

 Sioux quartzite, is very thinly spread on this 

 northeastern part of Kansas, under the loess, 

 and reaches about 30 miles south of Lansing, 

 terminating along an east to west boundary 

 12 to 15 miles south of the Kansas or Kaw 

 Eiver. 



The loess and the Lansing skeleton are of 

 Late Glacial age, but are probably twice or 

 perhaps three times as ancient as the traces of 

 man in his stone implements and quartz chips 

 occurring in glacial gravel and sand beds at 

 Trenton, N. J., and Little Falls, Minn. In 

 the Somme Valley and other parts of France, 

 as also in southern England, stone implements 

 in river drift prove that man existed there 

 before the Ice age, that is probably 100,000 

 years ago, or doubtless four or five times 

 longer ago than the date of the skeleton at 

 Lansing, Kansas. 



Warren Upham. ■ 



NOTES ON INORGANIC CHEMISTRY. 

 It appears from a recent paper in the 

 Berichte that Dr. Marckwald has at last suc- 

 ceeded in preparing a specimen of polonium, 

 the radio-active element associated with bis- 

 muth, in such a way that the question of its 

 being a peculiar form of bismuth itself may 

 be set aside. The method used was to take a 

 specimen of strongly radio-active oxychlorid 

 of bismuth, dissolve it in acid, and then pre- 

 cipitate the metal by a rod of pure metallic bis- 

 muth. Under these circumstances the bis- 

 muth becomes coated with a black deposit, 

 which seems to be nearly pure polonium, inas- 

 much as the radio-activity of the solution is 

 wholly concentrated in the black deposit, 

 which is itself extremely active. The amount 

 obtained from several kilos of pitchblende resi- 



dues was only a few milligrams, from which it 

 was estimated that the amount of polonium in 

 pitchblende is not over one gram per ton. Dr. 

 Marckwald hopes, however, to obtain enough 

 of the pure metal by this method to determine 

 its atomic weight. 



K. A. Hofmann has also continued his work 

 on radio-active substances from the uranium 

 minerals, especially upon radio-active lead. 

 The radium so obtained is very much more ac- 

 tive upon the photographic plate than is polo- 

 nium. A specimen of radio-active lead sulfid, 

 which acted powerfully upon a photographic 

 plate, was much weaker in discharging the 

 electroscope than a specimen of polonium 

 oxychlorid, which had no effect whatever 

 through a thin gutta percha film upon a photo- 

 graphic plate, even after twenty hours' expo- 

 sure. He found that radio-active lead prepa- 

 rations gain in activity by preservation in a 

 dry condition in closed tubes. A number of 

 metals seem capable of robbing uranium of its 

 activity. In one experiment a solution of pure 

 uranium was mixed with barium and the 

 latter precipitated by sulfuric acid. The ura- 

 nium thereby lost completely its activity both 

 toward the electroscope and toward the photo- 

 graphic plate; after standing two days in a 

 closed tube the uranium regained its activity. 

 The same phenomenon was observed in another 

 experiment when bismuth was substituted for 

 barium. A number of the rare earths, such as 

 thorium, erbium, didymium, cerium and lan- 

 thanum, are capable of receiving an induced 

 activity from uranium, and the same is true, 

 not only of barium, but also of strontium 

 and calcium. Activity is very slightly induced 

 in yttrium and not at all in giucinum and 

 zirconium. Lead receives a weak activity 

 when precipitated from the uranium solution 

 with sulfuric acid, but none at all when the 

 precipitant is caustic potash. 



The same number of the Berichte contains 

 a paper by Stock and Doht continuing their 

 investigations of stibin, SbH,. This hydrid 

 of antimony was obtained in the solid state 

 some years ago by Olszewski, but great diffi- 

 culty had been experienced by him and by 

 them in obtaining more than a very small 

 trace of the gas from the materials used. The 



