Deckmber 18, 1903.] 



SCIENCE. 



783 



periiiicnts that we have made, it was found 

 that, like radium, it causes the diamond to 

 phosphoresce, and exerts the same action 

 as radium upon kunzite and willeniite, 

 with the possible exception that the emana- 

 tions from the small quantity of substance 

 seemed to become luminous before they 

 touched the willemite itself. The surface 

 that was affected measured two square 

 inches, many times the surface of the 

 actinium. The effect produced on wil- 

 lemite was somewhat different from that 

 due to radium ; the luminescence ap- 

 parently penetrated the willemite, and at 

 the same time it almost seemed as if a 

 huninous emanation left the material. 



It was also found that on applying some 

 powdered and granulated willemite to the 

 inside of a closed jar, 12 cms. high, and 

 putting this over the actinium, which was 

 in a paper, the emanations made the en- 

 tire interior of the jar luminous. 



On the other hand, they do not appear 

 to possess the penetrating power through 

 glass that the radium compounds show ; 

 for in the same experiment they failed to 

 affect the willemite on the outside of the 

 jar, although the glass was only 11 mm. in 

 thickness. 



A platiiuuu-barium-cyanide screen im- 

 mediately responded when the actinium 

 was held against the black paper on the 

 back. The abundance of emanations from 

 the substance, rather than their penetrative 

 quality, seemed to be its characteristic. 



One of the properties of actinium which 

 Professor Curie mentions in his letters, is 

 the emitting of many emanations, which 

 last for some minutes. This last feature, 

 of endurance, was not observed. On 

 the other hand, a peculiarity of actinium, 

 as compared with radium, is that the eman- 

 ations, although much more profuse, dis- 

 appear in a few seconds. Another marked 

 feature is a certain visibility or materiality 

 of the emanation.s. This has been already 



referred to in some of the experiments 

 above described in connection with wil- 

 lemite. 



If actinium is placed in a paper over a 

 screen of the phosphorescent sidphide. of 

 zinc (Sidot's blende), the screen will be- 

 come illuminated, and on slightly blowing, 

 so as to produce a current of air, the light 

 is carried along the screen with the emana- 

 tions. It was found that the diamond was 

 affected quite as permanently as with 

 radium; so was the spodumene variety, 

 kunzite, and a specimen of willemite more 

 than two inches square. Emanations of 

 the actinium, which was in a double paper, 

 n se in a cone-shaped form and spread out 

 in an inverted cone on the base of the 

 willemite, illuminating both. 



George F. Kunz, 

 Charles Baskerville. 



AMKIUCAX ORXITBOWOISTS' U\IOX. 



The twenty-first congress of the Amer- 

 ican Ornithologists' Union convened in 

 Philadelphia, ]\Ionday evening, November 

 16. The business meeting was held in the 

 council room, and the public sessions, com- 

 mencing Tuesday, November 17, and last- 

 ing three days, were held in the lecture hall 

 of the Academy of Natural Sciences. 



Charles B. Cory, of Boston, was elected 

 president, Charles F. Batchulder, of Cam- 

 bridge, Mass., and E. "W. Nelson, of Wash- 

 ington, D. C, vice-presidents: John H. 

 Sage, of Portland, Conn., secretary; Dr. 

 Jonathan Dwight, Jr., of New York City, 

 treasurer; Frank I\I. Chapman, Ruthven 

 Deane, A. K. Fisher, Thos. S. Roberts, Wit- 

 mcr Stone, William Duteher and Charles 

 W. Richmond, members of the council. 



The ex-presidents of the union, Drs. J. 

 A. Allen and C. Hart Merriam, and Messrs. 

 William Brewster, D. G. Elliot and Robert 

 Ridgway are ex-officio members of the 

 council. 



Dr. Samuel W. Woodhouse, of Philadel- 



