SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE 

 OFFICIAL NOTICES AND PROCEEDINGS OF THE AMERICAN ASSOCIATION 

 FOR THE ADVANCEMENT OF SCIENCE. 



Friday, April 14, 1905. 



CO^TE'NTS. 



Penci rating Radiation associated with X- 

 rays: Professor Carl Barus 561 



The Biological Laboratory of the Bureau of 

 Fisheries at Woods Hole, Mass., Report of 

 Work for the Sii miner of 190 'f: Professor 

 Francis B. Sumner 566 



Albatross Expedition to the Eastern Pacific: 

 Alexander Agassiz 572 



Scientific Books: — 



Gierke's Problems in Astrophysics: Pro- 

 fessor Edwin B. Frost. Lacroix on Jm 

 Montaigne Pelee et ses eruptions: Ernest 

 Howe 574 



Scientific Journals and Articles 578 



Societies and Academies : — 



The New York Academy of Sciences, Sec- 

 tion of Astronomy, Physics and Chemistry : 

 Professor C. C. Trowbridge. Section of 

 Biology: Professor jNI. A. Bigelow. The 

 Society for Experimental Biology and Med- 

 icine: Dr. William J. Gies. The Geolog- 

 ical Society of Washington: Dr. Geo. Otis 

 Smith 579 



Discussion and Correspondence: — 



The Western Sierra Madre Mountains : 

 Dr. Edmund Otis Hovey. The Metric Sys- 

 tem again: Dr. W. J. Spillman. New 

 American Ostracoda : Arthur E. Beardsley 585 



Special Articles: — 



TJie Distribution of Fresh-Water Faunas as 

 an Evidence of Drainage Modifications : 

 Dr. Douglas Wilson Johnson 588 



Current Notes on Meteorology : — 



Long-range Weather Forecasts; The Low 

 Relative Humidity of Winnipeg in Winter; 

 Jelinek's Meteorologi<ial Instructions ; 

 Hann's Lehrhuch der Meteorologie; A New 

 Rain (lauge: The Micro-barograph; Notes: 

 Professor Pv. DeC. Ward 592 



A Comtemplated Magnetic Survey of the , 

 North Pacific Ocean by the Carnegie Insti- 

 tution: Dr. L. a. Bauer 594 



The Elizabeth Thompson Science Fund: Pro- 

 fessor Charles S. Minot 596 



Medals and Awards of the Royal Geograph- 

 ical Society 597 



Professor Wilhclm Ostwald at Harvard Uni- 

 versity 598 



A Conference of Anatomists 598 



Scientific Notes and Neics 599 



University and Educational News 600 



MSS. inteuded for publicatiou aud oooks, eic. luiended 

 for review should be sent to the Editor of Science, (-iarn- 

 son-on-Hudeon, N. Y. 



PENETRATING RADIATION ASSOCIATED 

 WITH THE X-RAYS. 



As the following investigation is made 

 with the aid of nuclei, certain of their 

 properties bearing on the present subject 

 will first have to be specified. Exhaustions 

 are preferably made at a pressure differ- 

 ence (Bp) just below the point (to be called 

 fog limit) at which dust-free non-energized 

 saturated air condenses without foreign 

 nuclei. 8p depends on the particular ap- 

 paratus used. 



1. Fleeting Nuclei.— het the X-radiation 

 to which the dust-free air is exposed be 

 relatively weak, so that the density of ion- 

 ization may remain below a certain critical 

 value. The nuclei observed on condensa- 

 tion are then very small and they require a 

 high ordei* of exhaustion, approaching the 

 fog-limit of non-energized air. They are 

 usually instantaneously generated (within 

 a second) by the radiation, so that their 

 number is definite independent of the time 

 of exposure. They decay in a few seconds 

 after the radiation ceases; /. e., roughly to 

 one half their number in two seconds, to 

 one fifth in twenty seconds in the iisual 

 exponential way. I fancy that these nuclei 

 are what most physicists would call ions; 

 but nevertheless the particles are not of a 



