April 15, 1921] 



SCIENCE 



363 



the Bureau of Standards, on Saturday, 

 April 23. If the length of the program re- 

 quires it, there wiU also be sessions on Friday, 

 April 22. Other meetings for the current 

 season are as follows: August 4, 5, Pacific 

 Coast Section at Berkeley; November 25, 26, 

 Chicago, December 27-31, Toronto, annual 

 meeting. 



Penikese Island, Blizzards Bay, was aban- 

 doned as a leper colony on March 10. The 

 thirteen lepers on the island with three from 

 Bridgeport, Conn., and two from Richmond, 

 Va., were transferred to the federal lepro- 

 sarium recently established at Carville, La. 



UNIVERSITY AND EDUCATIONAL 

 NEWS 



A BUILDING plan for its medical school in 

 Chicago has been adopted by the University 

 of Illinois in cooperation with the state de- 

 partment of public welfare. What was form- 

 erly a ball park, just south of the Cook County 

 Hospital, Chicago, is to become the campus. 

 The buildings now under construction are a 

 clinical institute, a new building for the Illi- 

 nois Charitable Eye and Ear Infirmary, a psy- 

 chiatric institute and an institute for crippled 

 children. Later; the clinical institute and the 

 orthopedic institute will be enlarged and addi- 

 tional buildings will be erected for infectious 

 diseases, venereal diseases, a research institute, 

 a library, class rooms, research laboratories 

 and a dental institute. The Elizabethan 

 style of architecture has been selected. 



The Senate of the University of London 

 has adopted a resolution to continue the phys- 

 iological laboratory at South Kensington until 

 the end of 1923. 



Dr. L. Emmett Holt, Carpentier professor 

 sf the diseases of children at the College of 

 Physicians and Surgeons, Columbia Univer- 

 sity, has resigned this chair and the adminis- 

 trative conduct of the department, and has 

 been appointed chemical professor of the dis- 

 eases of children. 



At the Harvard Medical School Dr. Philip 

 Drinker, of the Buffalo Foundry and Machine 



Co. and Dr. Douglas A. Thom have become 

 instructors of applied physiology and psy- 

 chiati'y, respectively. Dr. Frederick L. Wells, 

 director of the Psychological Department of 

 the Psychopathic Hospital, Boston, has been 

 given an appointment as instructor in experi- 

 mental psychopathology. 



Mr. F. C. Thompson, Sorby research fellow 

 of the Royal Society, has been appointed to 

 the chair of metallurgy in the University of 

 Manchester. 



DISCUSSION AND CORRESPONDENCE 



POSITIVE RAY ANALYSIS OF LITHIUM 



Applying the method of positive ray 

 analysis previously used^ to the element 

 lithium, I have recently found that it is com- 

 posed of two isotoi)es. With positive ions 

 from heated lithium salts G. P. Thomson 

 and F. W. Aston have also obtained two 

 components.^ In my experiments the metal 

 itself was evaporated in a small iron capsule, 

 heated electrically. The two rays correspond- 

 ing to atomic weights 6 and 7 were widely 

 separated and appeared simultaneously as the 

 heating current was increased. The absolute 

 atomic weights could be checked by compar- 

 ison with hydrogen atoms which were driven 

 off from the metal; the setting on the maxima 

 of the two components was so accurate that 

 assuming a molecular weight of exactly 6 for 

 the lighter, the heavier atomic weight was 7.00 

 within 2 units in the second decimal place, 

 thus excluding the possibility of a simple ele- 

 ment with the chemical atomic weight 6.94. 

 Any further isotopes at 4, 5, 8 or 9 must be 

 less than 2 per cent, of that at 7. 



It was also observed that the proportion of 

 the two components varies with the experi- 

 mental conditions. The lighter at 6 is some- 

 times one quarter as strong as that at 7, but 

 under other conditions of heating and pres- 

 sure, it appears weaker and sometimes is only 

 one twelfth as strong. To obtain a mean 

 atomic weight of 6.94 the lighter should be 

 only one sixteenth as strong as the heavier, 



1 Science, Deeemher 10, 1920. 



2 Nature, February 24, 1921. 



