November 21, 1913] 



SCIENCE 



741 



Highways Association ; John H. Delaney, com- 

 missioner, New York State Department of 

 Efficiency and Economy; A. W. Dow, chem- 

 ical and consulting paving engineer; H. W. 

 Durham, chief engineer of highways. Bor- 

 ough of Manhattan, New York City; C. N. 

 Forrest, chief chemist, New York Testing 

 Laboratory; Walter H. Eulweiler, chief chem- 

 ist, United Gas Improvement Company; 

 Prank B. Gilbreth, consulting engineer; 

 George P. Hemstreet, superintendent, The 

 Hastings Pavement Company; Samuel Hill, 

 president, American Road Builders' Associa- 

 tion; D. L. Hough, president, the United 

 Engineering and Contracting Company; J. 

 W. Howard, consulting engineer; Arthur N. 

 Johnson, state highway engineer of Illinois; 

 William H. Kershaw, manager. Paving and 

 Eoads Division, the Texas Company; Nelson 

 P. Lewis, chief engineer. Board of Estimate 

 and Apportionment, New York City; Harold 

 Parker, first vice-president, Hassam Paving 

 Company; Paul D. Sargent, chief engineer, 

 Maine State Highway Commission; Philip P. 

 Sharpies, chief chemist, Barrett Manufactur- 

 ing Company; Francis P. Smith, chemical 

 and consulting paving engineer; Albert Som- 

 mer, consulting chemist; George W. Tillson, 

 consulting engineer to the president of the 

 Borough of Brooklyn. 



Dr. O. W. Eichardson, F.E.S., professor of 

 physics in Princeton University, has been ap- 

 pointed to the Wheatstone chair of physics at 

 King's College, London, in succession to Pro- 

 fessor C. G. Barkla, F.E.S. 



Dr. Karl Boehm, of Heidelberg, has been 

 appointed professor of mathematics in the 

 University of Konigsberg as successor to Pro- 

 fessor G. Faber. 



DISCUSSION AND COEEESPONDENCM 

 ATOMIC IONIZATION AND ATOMIC CHARGES It will be Seen that while the ionization pro- 

 In a discussion of " The Eutherf ord Atom " duced by the /? and y rays is practically the 

 in Science for August 22 Mr. Fulcher gives same, that produced by the a rays is much 

 Kleeman's table of the relative ionization of less. In either case, however, there is a con- 

 different elements by the y8 and y radiation stant relation between the ionic charges and 

 and concludes that " atomic ionization seems the amount of ionization, showing that the 

 to depend primarily upon the atomic weight, greater the negative charge of the atom the 



which is probably proportional to the number 

 of electrons in the atom." 



Whatever theory of atomic structure we may 

 adopt, it seems certain that electrons are held 

 to their atoms by electrical forces in which 

 the mass of the atom can play no part. H a 

 relation exists between the mass of an atom 

 and its electrical charge, then a corresponding 

 relation should exist between its mass and its 

 attraction for electrons. Since the ionization 

 investigated by Kleeman consisted in the sep- 

 aration of electrons from their atoms by the 

 discharge of a, P and y radiation through the 

 substance, it seems probable that the weaker 

 the hold of the atoms upon their electrons the 

 greater would be their ionization. 



Elsewhere I have tried to show that it is 

 possible to calculate the electrical charges of 

 a number of free atoms from their atomic 

 mass and their velocity in electrolysis. If 

 the above reasoning is correct, the charges cal- 

 culated in this way should bear a definite re- 

 lation to the ionization in Kleeman's investi- 

 gation. 



Unfortunately, the atomic charges can be 

 calculated in this way for only four of the ele- 

 ments in Kleeman's table, but the indications 

 given by these four seem so conclusive that I 

 have thought it worth while to present them 

 here. The four elements referred to are hydro- 

 gen, chlorine, bromine and iodine. Their 

 relative ionization by the different rays and 

 their charges as electrolytic ions are given in 

 the table below. 



